Science.gov

Sample records for air conditioning assembly

  1. REACH. Air Conditioning Units.

    ERIC Educational Resources Information Center

    Garrison, Joe; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of air conditioning. The instructional units focus on air conditioning fundamentals, window air conditioning, system and installation, troubleshooting and…

  2. Air bearing vacuum seal assembly

    DOEpatents

    Booth, Rex

    1978-01-01

    An air bearing vacuum seal assembly capable of rotating at the speed of several thousand revolutions per minute using an air cushion to prevent the rotating and stationary parts from touching, and a two stage differential pumping arrangement to maintain the pressure gradient between the air cushion and the vacuum so that the leak rate into the vacuum is, for example, less than 1 .times. 10.sup.-4 Pa m.sup.3 /s. The air bearing vacuum seal has particular application for mounting rotating targets to an evacuated accelerator beam tube for bombardment of the targets with high-power charged particle beams in vacuum.

  3. Air-Conditioning Mechanic.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the skills needed by air conditioning mechanics. Addressed in the four chapters, or lessons, of the manual are the following topics: principles of air conditioning, refrigeration components as…

  4. High efficiency air cycle air conditioning system

    SciTech Connect

    Rannenberg, G. C.

    1985-11-19

    An air cycle air conditioning system is provided with regenerative heat exchangers upstream and downstream of an expansion turbine. A closedloop liquid circulatory system serially connects the two regenerative heat exchangers for regeneration without the bulk associated with air-to-air heat exchange. The liquid circulatory system may also provide heat transport to a remote sink heat exchanger and from a remote load as well as heat exchange within the sink heat exchanger and load for enhanced compactness and efficiency.

  5. Air Conditioning Does Reduce Air Pollution Indoors

    ERIC Educational Resources Information Center

    Healy, Bud

    1970-01-01

    Report of the winter meeting of the American Society of Heating, Refrigerating and Air-Conditioning Engineers. Subjects covered are--(1) title subject, (2) predictions for the human habitat in 1994, (3) fans, and (4) fire safety in buildings. (JW)

  6. Air conditioned suit

    NASA Technical Reports Server (NTRS)

    Carl, G. R. (Inventor)

    1973-01-01

    An environmentally controlled suit is described consisting of an airtight outergarment attached by an airtight bellows to the wall of a sterile chamber, an undergarment providing for circulation of air near the skin of the wearer, and a circulation system comprised of air supply and distribution to the extremities of the undegarment and central collection and exhaust of air from the midsection of the undergarment. A workman wearing the undergarment and attached circulation system enters the outer garment through a tunnel in the chamber wall and the attached bellows to work in the chamber without any danger of spreading bacteria.

  7. Air conditioning system

    DOEpatents

    Lowenstein, Andrew; Miller, Jeffrey; Gruendeman, Peter; DaSilva, Michael

    2005-02-01

    An air conditioner comprises a plurality of plates arranged in a successively stacked configuration with portions thereof having a spaced apart arrangement, and defining between successive adjacent pairs of plates at the spaced apart portions a first and second series of discrete alternating passages wherein a first air stream is passed through the first series of passages and a second air stream is passed through the second series of passages; and said stacked configuration of plates forming integrally therewith a liquid delivery means for delivering from a source a sufficient quantity of a liquid to the inside surfaces of the first series of fluid passages in a manner which provides a continuous flow of the liquid from a first end to a second end of the plurality of plates while in contact with the first air stream.

  8. Air Conditioning Overflow Sensor

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Technology Transfer Office at Stennis Space Center helped a local inventor develop a prototype of an attachment for central air conditioners and heat pumps that helps monitor water levels to prevent condensation overflow. The sensor will indicate a need for drain line maintenance and prevent possible damage caused by drain pan water spillover. An engineer in the Stennis Space Center prototype Development Laboratory used SSC sensor technology in the development of the sensor.

  9. Air conditioning and refrigeration engineering

    SciTech Connect

    Kreith, F.

    1999-12-01

    This book supplies the basics of design, from selecting the optimum system and equipment to preparing the drawings and specifications. It discusses the four phases of preparing a project: gathering information, developing alternatives, evaluating alternatives, and selling the best solution. In addition, the author breaks down the responsibilities of the engineer design documents, computer aided design, and government codes and standards. It provides you with an easy reference to all aspects of the topic. This resource addresses the most current areas of interest, such as computer aided design and drafting, desiccant air conditioning and energy conservation. It is a thorough and convenient guide to air conditioning and refrigeration engineering. Contents include: introduction; psychrometrics; air-conditioning processes and cycles; refrigerants and refrigeration cycles; outdoor design conditions and indoor design criteria; load calculations; air handling units and packaged units; refrigeration components and evaporative coolers; water systems; heating systems; refrigeration systems; thermal storage system; air system basics; absorption systems; air-conditioning systems and selection; and desiccant dehumidification and air-conditioning.

  10. Computer Developments in Air Conditioning.

    ERIC Educational Resources Information Center

    Pancoast, Ferendino, Grafton and Skeels, Architects, Miami, FL.

    Proceedings of a conference on the present and future uses of computer techniques in the air conditioning field. The recommendation of this report is, for the most part, negative insofar as it applies to the use of computers for design by the small office. However, there should be an awareness of their usefulness in controlling the environmental…

  11. High Energy Efficiency Air Conditioning

    SciTech Connect

    Edward McCullough; Patrick Dhooge; Jonathan Nimitz

    2003-12-31

    This project determined the performance of a new high efficiency refrigerant, Ikon B, in a residential air conditioner designed to use R-22. The refrigerant R-22, used in residential and small commercial air conditioners, is being phased out of production in developed countries beginning this year because of concerns regarding its ozone depletion potential. Although a replacement refrigerant, R-410A, is available, it operates at much higher pressure than R-22 and requires new equipment. R-22 air conditioners will continue to be in use for many years to come. Air conditioning is a large part of expensive summer peak power use in many parts of the U.S. Previous testing and computer simulations of Ikon B indicated that it would have 20 - 25% higher coefficient of performance (COP, the amount of cooling obtained per energy used) than R-22 in an air-cooled air conditioner. In this project, a typical new R-22 residential air conditioner was obtained, installed in a large environmental chamber, instrumented, and run both with its original charge of R-22 and then with Ikon B. In the environmental chamber, controlled temperature and humidity could be maintained to obtain repeatable and comparable energy use results. Tests with Ikon B included runs with and without a power controller, and an extended run for several months with subsequent analyses to check compatibility of Ikon B with the air conditioner materials and lubricant. Baseline energy use of the air conditioner with its original R-22 charge was measured at 90 deg F and 100 deg F. After changeover to Ikon B and a larger expansion orifice, energy use was measured at 90 deg F and 100 deg F. Ikon B proved to have about 19% higher COP at 90 deg F and about 26% higher COP at 100 deg F versus R-22. Ikon B had about 20% lower cooling capacity at 90 deg F and about 17% lower cooling capacity at 100 deg F versus R-22 in this system. All results over multiple runs were within 1% relative standard deviation (RSD). All of these

  12. Initial condition of stochastic self-assembly.

    PubMed

    Davis, Jason K; Sindi, Suzanne S

    2016-02-01

    The formation of a stable protein aggregate is regarded as the rate limiting step in the establishment of prion diseases. In these systems, once aggregates reach a critical size the growth process accelerates and thus the waiting time until the appearance of the first critically sized aggregate is a key determinant of disease onset. In addition to prion diseases, aggregation and nucleation is a central step of many physical, chemical, and biological process. Previous studies have examined the first-arrival time at a critical nucleus size during homogeneous self-assembly under the assumption that at time t=0 the system was in the all-monomer state. However, in order to compare to in vivo biological experiments where protein constituents inherited by a newly born cell likely contain intermediate aggregates, other possibilities must be considered. We consider one such possibility by conditioning the unique ergodic size distribution on subcritical aggregate sizes; this least-informed distribution is then used as an initial condition. We make the claim that this initial condition carries fewer assumptions than an all-monomer one and verify that it can yield significantly different averaged waiting times relative to the all-monomer condition under various models of assembly.

  13. Initial condition of stochastic self-assembly

    NASA Astrophysics Data System (ADS)

    Davis, Jason K.; Sindi, Suzanne S.

    2016-02-01

    The formation of a stable protein aggregate is regarded as the rate limiting step in the establishment of prion diseases. In these systems, once aggregates reach a critical size the growth process accelerates and thus the waiting time until the appearance of the first critically sized aggregate is a key determinant of disease onset. In addition to prion diseases, aggregation and nucleation is a central step of many physical, chemical, and biological process. Previous studies have examined the first-arrival time at a critical nucleus size during homogeneous self-assembly under the assumption that at time t =0 the system was in the all-monomer state. However, in order to compare to in vivo biological experiments where protein constituents inherited by a newly born cell likely contain intermediate aggregates, other possibilities must be considered. We consider one such possibility by conditioning the unique ergodic size distribution on subcritical aggregate sizes; this least-informed distribution is then used as an initial condition. We make the claim that this initial condition carries fewer assumptions than an all-monomer one and verify that it can yield significantly different averaged waiting times relative to the all-monomer condition under various models of assembly.

  14. Air conditioning system with supplemental ice storing and cooling capacity

    DOEpatents

    Weng, Kuo-Lianq; Weng, Kuo-Liang

    1998-01-01

    The present air conditioning system with ice storing and cooling capacity can generate and store ice in its pipe assembly or in an ice storage tank particularly equipped for the system, depending on the type of the air conditioning system. The system is characterized in particular in that ice can be produced and stored in the air conditioning system whereby the time of supplying cooled air can be effectively extended with the merit that the operation cycle of the on and off of the compressor can be prolonged, extending the operation lifespan of the compressor in one aspect. In another aspect, ice production and storage in great amount can be performed in an off-peak period of the electrical power consumption and the stored ice can be utilized in the peak period of the power consumption so as to provide supplemental cooling capacity for the compressor of the air conditioning system whereby the shift of peak and off-peak power consumption can be effected with ease. The present air conditioning system can lower the installation expense for an ice-storing air conditioning system and can also be applied to an old conventional air conditioning system.

  15. Concentrated Solar Air Conditioning for Buildings Project

    NASA Technical Reports Server (NTRS)

    McLaughlin, Rusty

    2010-01-01

    This slide presentation reviews project to implement the use of solar power to provide air conditioning for NASA buildings. Included is an overall conceptual schematic, and an diagram of the plumbing and instrumentation for the project. The use of solar power to power air conditioning in buildings, particularly in the Southwest, could save a significant amount of money. DOD studies have concluded that air conditioning accounts for 30-60% of total energy expenditures.

  16. Air Conditioning and Heating Technology--II.

    ERIC Educational Resources Information Center

    Gattone, Felix

    Twenty-eight chapters and numerous drawings provide information for instructors and students of air conditioning and heating technology. Chapter 1 lists the occupational opportunities in the field. Chapter 2 covers the background or development of the industry of air conditioning and heating technology. Chapter 3 includes some of the principle…

  17. HEATING AND AIR CONDITIONING EDUCATIONAL PROGRAM.

    ERIC Educational Resources Information Center

    Lennox Industries, Inc., Marshalltown, IA.

    INCREASED MOTIVATION, INCREASED INITIAL COMPREHENSION, AND INCREASED RETENTION ARE THE PRIME GOALS OF THE LENNOX HEATING AND AIR CONDITIONING EDUCATION PROGRAM. IT IS A COMPLETE PROGRAM WITH ALL THE TEACHING TOOLS REQUIRED TO PRODUCE A KNOWLEDGEABLE HEATING AND AIR-CONDITIONING INSTALLER OR SERVICE MAN. THIS INSTRUCTIONAL PROGRAM IS DESIGNED…

  18. Air Conditioning. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Long, William

    Several intermediate performance objectives and corresponding criterion measures are listed for each of seven terminal objectives for an intermediate air conditioning course. The titles of the seven terminal objectives are Refrigeration Cycle, Job Requirement Skills, Air Conditioning, Trouble Shooting, Performance Test, Shop Management, and S.I.E.…

  19. Air Conditioning. FOS: Fundamentals of Service.

    ERIC Educational Resources Information Center

    Employment and Training Administration (DOL), Washington, DC. Office of Youth Programs.

    This manual on air conditioning is one of a series of power mechanics texts and visual aids covering theory of operation, diagnosis, and repair. Information is presented for use by vocational students and teachers as well as shop servicemen and laymen. Focus is on air conditioning systems for mobile machines, but most of the information also…

  20. Breakthrough Video: Desiccant Enhanced Evaporative Air Conditioning

    SciTech Connect

    2012-01-01

    Researchers at the National Renewable Energy Laboratory (NREL) invented a breakthrough technology that improves air conditioning in a novel way—with heat. NREL combined desiccant materials, which remove moisture from the air using heat, and advanced evaporative technologies to develop a cooling unit that uses 90% less electricity and up to 80% less total energy than traditional air conditioning (AC). This solution, called the desiccant enhanced evaporative air conditioner (DEVAP), also controls humidity more effectively to improve the comfort of people in buildings.

  1. Zoned heating and air conditioning system

    SciTech Connect

    Beachboard, S.A.

    1987-06-16

    This patent describes a zoned heating and air conditioning system comprising: a central air handling system with an air heating means and an air cooling means and a blower connected to an air duct system; thermostats each have heating and cooling set points, respectively associated with and located in different zones of a building; dampers respectively associated with each building zone positioned in the air duct system. Each damper has an open position allowing air into the respective zone from the duct system and a closed position; relay means for connecting one thermostat to the air handling system upon a call for heating or cooling by one thermostat and disconnecting all other thermostats by connecting one thermostat's connections between the thermostat and air handling system. Only one thermostat is connected to the air handling system at a time and the relay means disconnects one thermostat from the air handling system after one thermostat is satisified; and damper actuating means for unlocking each damper in one building zone responsive actuated by a respective zone thermostat connected to the air handling system by the relay means. The damper actuates means including a damper solenoid for each damper located adjacent each damper and connected to a respective zone thermostat. It unlocks each damper in one building zone responsive to being actuated by the respective zone thermostat and unlocks the dampers in one building zone when one thermostat is actuated while preventing the dampers in another thermostat's building zone from unlocking.

  2. Reduced bleed air extraction for DC-10 cabin air conditioning

    NASA Technical Reports Server (NTRS)

    Newman, W. H.; Viele, M. R.; Hrach, F. J.

    1980-01-01

    It is noted that a significant fuel savings can be achieved by reducing bleed air used for cabin air conditioning. Air in the cabin can be recirculated to maintain comfortable ventilation rates but the quality of the air tends to decrease due to entrainment of smoke and odors. Attention is given to a development system designed and fabricated under the NASA Engine Component Improvement Program to define the recirculation limit for the DC-10. It is shown that with the system, a wide range of bleed air reductions and recirculation rates is possible. A goal of 0.8% fuel savings has been achieved which results from a 50% reduction in bleed extraction from the engine.

  3. Magnetic Refrigeration Technology for High Efficiency Air Conditioning

    SciTech Connect

    Boeder, A; Zimm, C

    2006-09-30

    Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate

  4. [Air quality control systems: heating, ventilating, and air conditioning (HVAC)].

    PubMed

    Bellucci Sessa, R; Riccio, G

    2004-01-01

    After a brief illustration of the principal layout schemes of Heating, Ventilating, and Air Conditioning (HVAC), the first part of this paper summarizes the standards, both voluntary and compulsory, regulating HVAC facilities design and installation with regard to the question of Indoor Air Quality (IAQ). The paper then examines the problem of ventilation systems maintenance and the essential hygienistic requirements in whose absence HVAC facilities may become a risk factor for people working or living in the building. Lastly, the paper deals with HVAC design strategies and methods, which aim not only to satisfy comfort and air quality requirements, but also to ensure easy and effective maintenance procedures.

  5. The Effect of Computers on School Air-Conditioning.

    ERIC Educational Resources Information Center

    Fickes, Michael

    2000-01-01

    Discusses the issue of increased air-conditioning demand when schools equip their classrooms with computers that require enhanced and costlier air-conditioning systems. Air-conditioning costs are analyzed in two elementary schools and a middle school. (GR)

  6. ALTERNATIVE TECHNOLOGIES FOR REFRIGERATION AND AIR-CONDITIONING APPLICATIONS

    EPA Science Inventory

    The report gives results of an assessment of refrigeration technologies that are alternatives to vapor compression refrigeration for use in five application categories: domestic air conditioning, commercial air conditioning, mobile air conditioning, domestic refrigeration, and co...

  7. Air Conditioning and Refrigeration Book IV.

    ERIC Educational Resources Information Center

    Eckes, William; Fulkerson, Dan

    This publication is the concluding text in a four-part curriculum for air conditioning and refrigeration. Materials in Book 4 are designed to complement theoretical and functional elements in Books 1-3. Instructional materials in this publication are written in terms of student performance using measurable objectives. The course includes six…

  8. Readings in Air Conditioning and Refrigeration.

    ERIC Educational Resources Information Center

    Uberto, Jeffrey A.

    Designed to encourage vocational high school students to read by offering reading materials relevant to their vocational goals, this document contains thirty-seven articles related to air conditioning and refrigeration which have been selected from trade journals, magazines, and newspapers and adapted to the students' reading capabilities. A…

  9. Air Conditioning and Refrigeration Book III.

    ERIC Educational Resources Information Center

    Eckes, William; Fulkerson, Dan

    Designed to present theory as a functional aspect, this air conditioning and refrigeration curriculum guide is comprised of nine units of instruction. Unit titles include (1) Job Orientation, (2) Applying for a Job, (3) Customer Relations, (4) Business Management, (5) Psychometrics, (6) Residential Heat Loss and Heat Gain, (7) Duct Design and…

  10. Fundamentals of Air Conditioning and Refrigeration.

    ERIC Educational Resources Information Center

    Clemons, Mark

    This set of instructional materials provides secondary and postsecondary students with a state-of-the-art curriculum for the air conditioning and refrigeration industry that includes the many changes brought by new Environmental Protection Agency (EPA) regulations. Introductory materials explain the use of this publication and provide the…

  11. Air Conditioning and Refrigeration. Book One.

    ERIC Educational Resources Information Center

    Wantiez, Gary W.

    Designed to provide students with the basic skills for an occupation in air conditioning and refrigeration, this curriculum guide includes seven major areas, each consisting of one or more units of instruction. These areas and their respective units are titled as follows: Orientation (history and development, and job opportunities), Safety…

  12. Air Conditioning and Refrigeration. Book Two.

    ERIC Educational Resources Information Center

    Wantiez, Gary W.

    This curriculum guide (book II), along with book I, is designed to provide students with the basic skills for an occupation in air conditioning and refrigeration. Six major areas are included, each consisting of one or more units of instruction. These areas and their respective units are titled as follows: Electricity (fundamentals of electricity,…

  13. MOBILE AIR-CONDITIONING RECYCLING MANUAL

    EPA Science Inventory

    The report gives guidelines on the recovery and recycle of the chlorofluorocarbon (CFC), dichlorodifluoromethane (CFC-12), from mobile air conditions. It is intended for wide distribution internationally and is especially for use by developing countries and the World Bank to ass...

  14. Air Conditioning and Refrigeration Supplementary Units.

    ERIC Educational Resources Information Center

    Winston, Del; And Others

    This document contains supplemental materials for special needs high school students intended to facilitate their mainstreaming in regular air conditioning and refrigeration courses. Teacher's materials precede the materials for students and include general notes for the instructor, additional suggestions, two references, a questionnaire on the…

  15. Standardized Curriculum for Heating and Air Conditioning.

    ERIC Educational Resources Information Center

    Mississippi State Dept. of Education, Jackson. Office of Vocational, Technical and Adult Education.

    Standardized vocational education course titles and core contents for two courses in Mississippi are provided: heating and air conditioning I and II. The first course contains the following units: (1) orientation; (2) safety; (3) refrigeration gauges and charging cylinder; (4) vacuum pump service operations; (5) locating refrigerant leaks; (6)…

  16. Thermal conditions and perceived air quality in an air-conditioned auditorium

    NASA Astrophysics Data System (ADS)

    Polednik, Bernard; Guz, Łukasz; Skwarczyński, Mariusz; Dudzińska, Marzenna R.

    2016-07-01

    The study reports measurements of indoor air temperature (T) and relative humidity (RH), perceived air quality (PAQ) and CO2, fine aerosol particle number (PN) and mass (PM1) concentrations in an air conditioned auditorium. The measurements of these air physical parameters have been carried out in the unoccupied auditorium with the air conditioning system switched off (AC off mode) and in the unoccupied and occupied auditorium with the air conditioning system switched off during the night and switched on during the day (AC on/off mode). The average indoor air thermal parameters, CO2 concentration and the PAQ value (in decipols) were elevated, while average PM1 concentration was lower in the AC on/off mode. A statistically significant (p < 0.001) positive correlation has been observed between T and PAQ values and CO2 concentrations (r = 0.66 and r = 0.59, respectively) in that AC mode. A significant negative correlation has been observed between T and PN and PM1 concentrations (r = -0.38 and r = -0.49, respectively). In the AC off mode the above relations between T and the particle concentrations were not that unequivocal. These findings may be of importance as they indicate that in certain AC operation modes the indoor air quality deteriorates along with the variation of the indoor air microclimate and room occupation. This, in turn, may adversely affect the comfort and productivity of the users of air conditioned premises.

  17. Smart sensors enable smart air conditioning control.

    PubMed

    Cheng, Chin-Chi; Lee, Dasheng

    2014-01-01

    In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants' information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans' intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be controlled accurately with errors of less than ±0.1 °C. Rapid cool down can be achieved within 2 min to the optimized indoor capacity after occupants enter a room. It's also noted that within two-hour operation the total compressor output of the smart air conditioner is 48.4% less than that of the one using On-Off control. The smart air conditioner with wearable devices could detect the human temperature and activity during sleep to determine the sleeping state and adjusting the sleeping function flexibly. The sleeping function optimized by the smart air conditioner with wearable devices could reduce the energy consumption up to 46.9% and keep the human health. The presented smart air conditioner could provide a comfortable environment and achieve the goals of energy conservation and environmental protection. PMID:24961213

  18. Smart sensors enable smart air conditioning control.

    PubMed

    Cheng, Chin-Chi; Lee, Dasheng

    2014-06-24

    In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants' information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans' intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be controlled accurately with errors of less than ±0.1 °C. Rapid cool down can be achieved within 2 min to the optimized indoor capacity after occupants enter a room. It's also noted that within two-hour operation the total compressor output of the smart air conditioner is 48.4% less than that of the one using On-Off control. The smart air conditioner with wearable devices could detect the human temperature and activity during sleep to determine the sleeping state and adjusting the sleeping function flexibly. The sleeping function optimized by the smart air conditioner with wearable devices could reduce the energy consumption up to 46.9% and keep the human health. The presented smart air conditioner could provide a comfortable environment and achieve the goals of energy conservation and environmental protection.

  19. Smart Sensors Enable Smart Air Conditioning Control

    PubMed Central

    Cheng, Chin-Chi; Lee, Dasheng

    2014-01-01

    In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants' information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans' intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be controlled accurately with errors of less than ±0.1 °C. Rapid cool down can be achieved within 2 min to the optimized indoor capacity after occupants enter a room. It's also noted that within two-hour operation the total compressor output of the smart air conditioner is 48.4% less than that of the one using On-Off control. The smart air conditioner with wearable devices could detect the human temperature and activity during sleep to determine the sleeping state and adjusting the sleeping function flexibly. The sleeping function optimized by the smart air conditioner with wearable devices could reduce the energy consumption up to 46.9% and keep the human health. The presented smart air conditioner could provide a comfortable environment and achieve the goals of energy conservation and environmental protection. PMID:24961213

  20. Alternative Air Conditioning Technologies: Underfloor AirDistribution (UFAD)

    SciTech Connect

    Webster, Tom

    2004-06-01

    Recent trends in today's office environment make it increasingly more difficult for conventional centralized HVAC systems to satisfy the environmental preferences of individual officer workers using the standardized approach of providing a single uniform thermal and ventilation environment. Since its original introduction in West Germany during the 1950s, the open plan office containing modular workstation furniture and partitions is now the norm. Thermostatically controlled zones in open plan offices typically encompass relatively large numbers of workstations in which a diverse work population having a wide range of preferred temperatures must be accommodated. Modern office buildings are also being impacted by a large influx of heat-generating equipment (computers, printers, etc.) whose loads may vary considerably from workstation to workstation. Offices are often reconfigured during the building's lifetime to respond to changing tenant needs, affecting the distribution of within-space loads and the ventilation pathways among and over office partitions. Compounding this problem, there has been a growing awareness of the importance of the comfort, health, and productivity of individual office workers, giving rise to an increased demand among employers and employees for a high-quality work environment. During recent years an increasing amount of attention has been paid to air distribution systems that individually condition the immediate environments of office workers within their workstations to address the issues outlined above. As with task/ambient lighting systems, the controls for the ''task'' components of these systems are partially or entirely decentralized and under the control of the occupants. Typically, the occupant has control over the speed and direction, and in some cases the temperature, of the incoming air supply. Variously called ''task/ambient conditioning,'' ''localized thermal distribution,'' and ''personalized air conditioning'' systems, these

  1. Innovative Air Conditioning and Climate Control

    NASA Technical Reports Server (NTRS)

    Graf, John

    2015-01-01

    NASA needed to develop a desiccant wheel based humidity removal system to enable the long term testing of the Orion CO2 scrubber on the International Space Station. In the course of developing that system, we learned three things that are relevant to energy efficient air conditioning of office towers. NASA developed a conceptual design for a humidity removal system for an office tower environment. We are looking for interested partners to prototype and field test this concept.

  2. Seminar 14 - Desiccant Enhanced Air Conditioning: Desiccant Enhanced Evaporative Air Conditioning (Presentation)

    SciTech Connect

    Kozubal, E.

    2013-02-01

    This presentation explains how liquid desiccant based coupled with an indirect evaporative cooler can efficiently produce cool, dry air, and how a liquid desiccant membrane air conditioner can efficiently provide cooling and dehumidification without the carryover problems of previous generations of liquid desiccant systems. It provides an overview to a liquid desiccant DX air conditioner that can efficiently provide cooling and dehumidification to high latent loads without the need for reheat, explains how liquid desiccant cooling and dehumidification systems can outperform vapor compression based air conditioning systems in hot and humid climates, explains how liquid desiccant cooling and dehumidification systems work, and describes a refrigerant free liquid desiccant based cooling system.

  3. Automatic air flow control in air conditioning ducts

    NASA Technical Reports Server (NTRS)

    Obler, H. D.

    1972-01-01

    Device is designed which automatically selects air flow coming from either of two directions and which can be adjusted to desired air volume on either side. Device uses one movable and two fixed scoops which control air flow and air volume.

  4. Alternative non-CFC mobile air conditioning

    SciTech Connect

    Mei, V.C.; Chen, F.C.; Kyle, D.M.

    1992-09-01

    Concern about the destruction of the global environment by chlorofluorocarbon (CFC) fluids has become an impetus in the search for alternative, non-CFC refrigerants and cooling methods for mobile air conditioning (MAC). While some alternative refrigerants have been identified, they are not considered a lasting solution because of their high global warming potential, which could result in their eventual phaseout. In view of this dilemma, environmentally acceptable alternative cooling methods have become important. This report, therefore, is aimed mainly at the study of alternative automotive cooling methodologies, although it briefly discusses the current status of alternative refrigerants. The alternative MACs can be divided into work-actuated and heat-actuated systems. Work-actuated systems include conventional MAC, reversed Brayton air cycle, rotary vane compressor air cycle, Stirling cycle, thermoelectric (TE) cooling, etc. Heat-actuated MACs include metal hydride cooling, adsorption cooling, ejector cooling, absorption cycle, etc. While we are better experienced with some work-actuated cycle systems, heat-actuated cycle systems have a high potential for energy savings with possible waste heat applications. In this study, each altemative cooling method is discussed for its advantages and its limits.

  5. Thickness and air gap measurement of assembled IR objectives

    NASA Astrophysics Data System (ADS)

    Lueerss, B.; Langehanenberg, P.

    2015-05-01

    A growing number of applications like surveillance, thermography, or automotive demand for infrared imaging systems. Their imaging performance is significantly influenced by the alignment of the individual lens elements. Besides the lateral orientation of lenses, the air spacing between the lenses is a crucial parameter. Because of restricted mechanical accessibility within an assembled objective, a non-contact technique is required for the testing of these parameters. So far commercial measurement systems were not available for testing of IR objectives since many materials used for infrared imaging are non-transparent at wavelengths below 2 μm. We herewith present a time-domain low coherent interferometer capable of measuring any kind of infrared material (e.g., Ge, Si, etc.) as well as VIS materials. The fiber-optic set-up is based on a Michelson-Interferometer in which the light from a broadband super-luminescent diode is split into a reference arm with a variable optical delay and a measurement arm where the sample is placed. On a photo detector, the reflected signals from both arms are superimposed and recorded as a function of the variable optical path. Whenever the group delay difference is zero, a coherence peak occurs and the relative lens' surface distances are derived from the optical delay. In order to penetrate IR materials, the instrument operates at 2.2 μm. The set-up allows the contactless determination of thicknesses and air gaps inside of assembled infrared objective lenses with accuracy in the micron range. It therefore is a tool for the precise manufacturing or quality control.

  6. Thickness and air gap measurement of assembled IR objectives

    NASA Astrophysics Data System (ADS)

    Lueerss, B.; Langehanenberg, P.

    2015-10-01

    A growing number of applications like surveillance, thermography, or automotive demand for infrared imaging systems. Their imaging performance is significantly influenced by the alignment of the individual lenses. Besides the lateral orientation of lenses, the air spacing between the lenses is a crucial parameter. Because of restricted mechanical accessibility within an assembled objective, a non-contact technique is required for the testing of these parameters. So far, commercial measurement systems were not available for testing of IR objectives since most materials used for infrared imaging are non-transparent at wavelengths below 2 μm. We herewith present a time-domain low coherent interferometer capable of measuring any kind of infrared material (e.g., Ge, Si, etc.) as well as VIS materials. The set-up is based on a Michelson interferometer in which the light from a broadband superluminescent diode is split into a reference arm with a variable optical delay and a measurement arm where the sample is placed. On a detector, the reflected signals from both arms are superimposed and recorded as a function of the variable optical path. Whenever the group delay difference is zero, a coherence peak occurs and the relative distances of the lens surfaces are derived from the optical delay. In order to penetrate IR materials, the instrument operates at 2.2 μm. Together with an LWIR autocollimator, this technique allows for the determination of centering errors, lens thicknesses and air spacings of assembled IR objective lenses with a micron accuracy. It is therefore a tool for precision manufacturing and quality control.

  7. Aluminum-air power cell: The M4-cell assembly and initial tests

    NASA Astrophysics Data System (ADS)

    Maimoni, A.; Muelder, S. A.; Hui, W. C.

    1985-10-01

    We fabricated, assembled, and tested the modular, wedge-shaped M4 Aluminum-Air Power Cell in a system with a fluidized-bed crystallizer and hydrocyclone separator. Two M4-cell experiments validated the design premises and indicated predictable performance. The combined duration of the M4-1 and M4-2 experiments was almost 9 h. Conductive epoxy bonds are inadequate for bonding the air-cathode metal screen to current collectors; soldered joints using low melting (93C) Indium solder performed satisfactorily. Both experiments were terminated because of problems directly traceable to metallic tin deposited by the stannate corrosion inhibitor. Apart from problems caused by metallic tin, the M4-2 test system performed very satisfactorily. Individual cell pods are readily assembled into single or multicell stacks; it is easy to disassemble the cells after a run to determine cell condition. Air-cathode assembly is the most cumbersome aspect of the M4 cell. We obtained valuable information regarding the evolution of particle-size distribution. We did not observe substantial agglomeration of the smaller crystals. A simple model of secondary nucleation gave a reasonably good fit to the secondary nucleation observed in the M3-3 experiment.

  8. Indoor air quality investigation at air-conditioned and non-air-conditioned markets in Hong Kong.

    PubMed

    Guo, H; Lee, S C; Chan, L Y

    2004-05-01

    To characterize indoor air quality at the markets in Hong Kong, three non-air-conditioned and two air-conditioned markets were selected for this study. The indoor air pollutants measured included PM(10) (particulate matters with aerodynamic diameter less than 10 microm), total bacteria count (TBC), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO(2)) and sulfur dioxide (SO(2)). The indoor and outdoor concentrations of these target air pollutants at these markets were measured and compared. The effects of air conditioning, temperature/relative humidity variation and different stalls on the indoor air quality were also investigated. The results indicated that all of the average indoor concentrations of PM(10), TBC, CO and NO(2) at the markets were below the Hong Kong Indoor Air Quality Objectives (HKIAQO) standards with a few exceptions for PM(10) and TBC. The elevated PM(10) concentrations at Hung Hom, Ngau Tau Kok and Wan Chai markets were probably due to the air filtration of outdoor airborne particulates emitted from vehicular exhaust, whereas high concentrations of airborne bacteria at Sai Ying Pun and Tin Shing markets were linked to the use of air conditioning. Correlation analysis demonstrated that indoor bacteria concentrations were correlated with temperature and relative humidity. The operation of air conditioning did not significantly reduce the levels of air pollutants at the markets. However, the higher indoor/outdoor ratios demonstrated that the operation of air conditioning had influence on the levels of bacteria at the markets. It was found that average PM(10) concentration at poultry stalls was higher than the HKIAQO standard of 180 microg/m(3), and was over two times that measured at vegetable, fish and meat stalls. Furthermore, the concentration of airborne bacteria at the poultry stalls was as high as 1031 CFU/m(3), which was above the HKIAQO standard of 1000 CFU/m(3). The bacteria levels at other three stalls were all below the

  9. Refrigeration, Heating & Air Conditioning. Post Secondary Curriculum Guide.

    ERIC Educational Resources Information Center

    Garrison, Joe C.; And Others

    This curriculum guide was designed for use in postsecondary refrigeration, heating and air conditioning education programs in Georgia. Its purpose is to provide for the development of entry level skills in refrigeration, heating, and air conditioning in the areas of air conditioning knowledge, theoretical structure, tool usage, diagnostic ability,…

  10. Self-Assembled Silicon Nanotubes under Supercritically Hydrothermal Conditions

    NASA Astrophysics Data System (ADS)

    Tang, Y. H.; Pei, L. Z.; Chen, Y. W.; Guo, C.

    2005-09-01

    Self-assembled silicon nanotubes with one-dimensional structure have been synthesized from silicon monoxide powder under supercritically hydrothermal conditions with a temperature of 470 °C and a pressure of 6.8 MPa. The silicon nanotubes were identified by transmission electron microscopy and high-resolution transmission electron microscopy. The results show that the silicon nanotubes (SiNT) have closed caps. The structures of the silicon nanotubes are hollow inner pore, crystalline silicon wall layers with a 0.31 nm interplanar spacing and 2-3 nm amorphous silica outer layers. Pure crystalline silicon nanotubes survive after etching the silicon nanotubes with 5% HF acid for enough time to imply that the self-assembled silicon nanotubes are stable. A possible theoretical reason for the growth of SiNTs from SiO under supercritically hydrothermal conditions was also proposed.

  11. Heating, ventilation and air conditioning systems

    SciTech Connect

    Kyle, D.M.; Sullivan, R.A.

    1993-02-01

    A study is made of several outstanding issues concerning the commercial development of environmental control systems for electric vehicles (EVs). Engineering design constraints such as federal regulations and consumer requirements are first identified. Next, heating and cooling loads in a sample automobile are calculated using a computer model available from the literature. The heating and cooling loads are then used as a basis for estimating the electrical consumption that is to be expected for heat pumps installed in EVs. The heat pump performance is evaluated using an automobile heat pump computer model which has been developed recently at Oak Ridge National Laboratory (ORNL). The heat pump design used as input to the model consists of typical finned-tube heat exchangers and a hermetic compressor driven by a variable-speed brushless dc motor. The simulations suggest that to attain reasonable system efficiencies, the interior heat exchangers that are currently installed as automobile air conditioning will need to be enlarged. Regarding the thermal envelope of the automobile itself, calculations are made which show that considerable energy savings will result if steps are taken to reduce {open_quote}hot soak{close_quote} temperatures and if the outdoor air ventilation rate is well controlled. When these changes are made, heating and cooling should consume less than 10% of the total stored electrical energy for steady driving in most U.S. climates. However, this result depends strongly upon the type of driving: The fraction of total power for heating and cooling ({open_quote}range penalty{close_quote}) increases sharply for driving scenarios having low average propulsion power, such as stop-and-go driving.

  12. Orientation-controlled parallel assembly at the air-water interface

    NASA Astrophysics Data System (ADS)

    Park, Kwang Soon; Hao Hoo, Ji; Baskaran, Rajashree; Böhringer, Karl F.

    2012-10-01

    This paper presents an experimental and theoretical study with statistical analysis of a high-yield, orientation-specific fluidic self-assembly process on a preprogrammed template. We demonstrate self-assembly of thin (less than few hundred microns in thickness) parts, which is vital for many applications in miniaturized platforms but problematic for today's pick-and-place robots. The assembly proceeds row-by-row as the substrate is pulled up through an air-water interface. Experiments and analysis are presented with an emphasis on the combined effect of controlled surface waves and magnetic force. For various gap values between a magnet and Ni-patterned parts, magnetic force distributions are generated using Monte Carlo simulation and employed to predict assembly yield. An analysis of these distributions shows that a gradual decline in yield following the probability density function can be expected with degrading conditions. The experimentally determined critical magnetic force is in good agreement with a derived value from a model of competing forces acting on a part. A general set of design guidelines is also presented from the developed model and experimental data.

  13. Air Conditioner Charging. Automotive Mechanics. Air Conditioning. Instructor's Guide [and] Student Guide.

    ERIC Educational Resources Information Center

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automobile air conditioning, consists of a student guide and an instructor guide dealing with air conditioning charging. Covered in the module are checking the air conditioning system for leaks, checking and adding refrigerant oil as needed, evacuating the system,…

  14. Microtrap assembly for greenhouse gas and air pollution monitoring

    SciTech Connect

    Mitra, Somenath; Saridara, Chutarat

    2015-08-25

    A microtrap assembly includes a carbon nanotube sorbent. The microtrap assembly may be employed as a preconcentrator operable to deliver a sample to an analytical device to measure the concentrations of greenhouse gases. A system includes a microtrap having a carbon nanotube sorbent for measuring the concentrations of greenhouse gases in a sample.

  15. Possible Economies in Air-Conditioning by Accepting Temperature Swings.

    ERIC Educational Resources Information Center

    Loudon, A. G.; Petherbridge, P.

    Public building air conditioning systems, which use constant and varying heat and cooling loads, are compared and investigated. Experiments indicated that constant temperature controls based on outside air temperature alone were inefficient. Ventilating a building with outside air and the methods of doing so are cited as being the most economical…

  16. Repair Air Conditioning, COC Bldg 2605, First Floor Plan. By ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Repair Air Conditioning, COC Bldg 2605, First Floor Plan. By Strategic Air Command, Civil Engineering. Drawing no. R-156, sheet no. 2 of 4, 15 August 1968; project no. MAR-125-8;CE-572; file drawer 2605-6. Scale one-eighth inch to one foot. 29x41 inches. pencil on paper 405 - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  17. Repair Air Conditioning, COC Bldg 2605, Basement Plan. By Strategic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Repair Air Conditioning, COC Bldg 2605, Basement Plan. By Strategic Air Command, Civil Engineering. Drawing no. R-156, sheet no. 1 of 4, 15 August 1968; project no. MAR-125-8;CE-572; file drawer 2605-5. Last revised 31 August 1968?. Scale one-eighth inch and one-quarter inch to one foot. 29x41 inches. pencil on paper - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  18. Solar-powered air-conditioning

    NASA Technical Reports Server (NTRS)

    Clark, D. C.; Rousseau, J.

    1977-01-01

    Report focuses on recent study on development of solar-powered residential air conditioners and is based on selected literature through 1975. Its purposes are to characterize thermal and mechanical systems that might be useful in development of Rankine-cycle approach to solar cooling and assessment of a Lithium Bromide/Water absorption cycle system.

  19. The Influence of Meteorological Conditions on Air Pollution

    ERIC Educational Resources Information Center

    Campbell, N. A.; Gipps, J.

    1975-01-01

    Explains the distribution of air pollutants as related to such meteorological conditions as temperature inversions, ground inversion, and wind velocity. Uses a power station to illustrate the effect of some of the meteorological conditions mentioned. (GS)

  20. Air Conditioning and Refrigeration Program Articulation, 1981-1982.

    ERIC Educational Resources Information Center

    Dallas County Community Coll. District, TX.

    Based on a survey of high school programs and courses in the Dallas County Community College District (DCCCD), this articulated program is designed to prepare students for entry-level employment in the air conditioning and refrigeration industry, including residential and commercial air conditioning and commercial refrigeration. The skills and…

  1. Thermal Environment for Classrooms. Central System Approach to Air Conditioning.

    ERIC Educational Resources Information Center

    Triechler, Walter W.

    This speech compares the air conditioning requirements of high-rise office buildings with those of large centralized school complexes. A description of one particular air conditioning system provides information about the system's arrangement, functions, performance efficiency, and cost effectiveness. (MLF)

  2. Energy Efficiency for Heating, Ventilating, Air-Conditioning Instructors.

    ERIC Educational Resources Information Center

    Scharmann, Larry, Ed.; Lay, Gary, Ed.

    Intended primarily but not solely for use at the postsecondary level, this curriculum guide contains five units on energy efficiency that were designed to be incorporated into an existing program in heating, ventilating, and air-conditioning. The following topics are examined: how energy conservation pays, heating, ventilation, air-conditioning,…

  3. Heating, Ventilation, and Air Conditioning Series. Duty Task List.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This task list is intended for use in planning and/or evaluating a competency-based course in heating, ventilation, and air conditioning. The guide outlines the tasks entailed in eight different duties typically required of employees in the following occupations: residential installer, domestic refrigeration technician, air conditioning and…

  4. Mountain Plains Learning Experience Guide: Heating, Refrigeration, & Air Conditioning.

    ERIC Educational Resources Information Center

    Carey, John

    This Heating, Refrigeration, and Air Conditioning course is comprised of eleven individualized units: (1) Refrigeration Tools, Materials, and Refrigerant; (2) Basic Heating and Air Conditioning; (3) Sealed System Repairs; (4) Basic Refrigeration Systems; (5) Compression Systems and Compressors; (6) Refrigeration Controls; (7) Electric Circuit…

  5. BEETIT: Building Cooling and Air Conditioning

    SciTech Connect

    2010-09-01

    BEETIT Project: The 14 projects that comprise ARPA-E’s BEETIT Project, short for “Building Energy Efficiency Through Innovative Thermodevices,” are developing new approaches and technologies for building cooling equipment and air conditioners. These projects aim to drastically improve building energy efficiency and reduce greenhouse gas emissions such as carbon dioxide (CO2) at a cost comparable to current technologies.

  6. Diagnostic device for monitoring the technical condition of mechanical assemblies

    NASA Technical Reports Server (NTRS)

    Osovskiy, V. I.; Shergin, V. V.; Shumilin, V. I.

    1973-01-01

    An automatic diagnostic device for monitoring the condition of tractor transmission gears is described. The structural noise spectrum of the gearshift box and rear axle of the tractor were analyzed in a digital computer, by an algorithm based on the multiple correlation method. The optimum assembly of operating frequencies, by use of which the errors in measurement were minimized, was selected from the entire frequency spectrum. Selected frequencies are necessary for choosing the measurement range of the diagnostic device. It turned out that, to obtain a relative error of no more than 2%, it was sufficient to use two filters, vibrating only at the frequencies carrying the maximum data of the mechanical parameter being investigated. The measurement system consists of frequency-selection filters, amplifiers and quadratic detectors, at the outlets of which constant voltages are created, which are proportional to the signal level at the frequencies selected.

  7. Air conditioning system and component therefore distributing air flow from opposite directions

    NASA Technical Reports Server (NTRS)

    Obler, H. D.; Bauer, H. B. (Inventor)

    1974-01-01

    The air conditioning system comprises a plurality of separate air conditioning units coupled to a common supply duct such that air may be introduced into the supply duct in two opposite flow directions. A plurality of outlets such as registers or auxiliary or branch ducts communicate with the supply duct and valve means are disposed in the supply duct at at least some of the outlets for automatically channelling a controllable amount of air from the supply duct to the associated outlet regardless of the direction of air flow within the supply duct. The valve means comprises an automatic air volume control apparatus for distribution within the air supply duct into which air may be introduced from two opposite directions. The apparatus incorporates a freely swinging movable vane in the supply duct to automatically channel into the associated outlet only the deflected air flow which has the higher relative pressure.

  8. Air-conditioning in the human nasal cavity.

    PubMed

    Elad, David; Wolf, Michael; Keck, Tilman

    2008-11-30

    Healthy humans normally breathe through their nose even though its complex geometry imposes a significantly higher resistance in comparison with mouth breathing. The major functional roles of nasal breathing are defense against infiltrating particles and conditioning of the inspired air to nearly alveolar conditions in order to maintain the internal milieu of the lung. The state-of-the-art of the existing knowledge on nasal air-conditioning will be discussed in this review, including in vivo measurements in humans and computational studies on nasal air-conditioning capacity. Areas where further studies will improve our understanding and may help medical diagnosis and intervention in pathological states will be introduced. PMID:18565805

  9. International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Failures and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Balistreri, Steven F.; Shaw, Laura A.; Laliberte, Yvon

    2010-01-01

    The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within in the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings and potential remediation techniques will also be discussed.

  10. Desiccant Enhanced Evaporative Air Conditioning: Parametric Analysis and Design; Preprint

    SciTech Connect

    Woods, J.; Kozubal, E.

    2012-10-01

    This paper presents a parametric analysis using a numerical model of a new concept in desiccant and evaporative air conditioning. The concept consists of two stages: a liquid desiccant dehumidifier and a dew-point evaporative cooler. Each stage consists of stacked air channel pairs separated by a plastic sheet. In the first stage, a liquid desiccant film removes moisture from the process (supply-side) air through a membrane. An evaporatively-cooled exhaust airstream on the other side of the plastic sheet cools the desiccant. The second-stage indirect evaporative cooler sensibly cools the dried process air. We analyze the tradeoff between device size and energy efficiency. This tradeoff depends strongly on process air channel thicknesses, the ratio of first-stage to second-stage area, and the second-stage exhaust air flow rate. A sensitivity analysis reiterates the importance of the process air boundary layers and suggests a need for increasing airside heat and mass transfer enhancements.

  11. Assemblies of protective anion exchange membrane on air electrode for its efficient operation in aqueous alkaline electrolyte

    NASA Astrophysics Data System (ADS)

    Bertolotti, Bruno; Chikh, Linda; Vancaeyzeele, Cédric; Alfonsi, Séverine; Fichet, Odile

    2015-01-01

    Aqueous alkaline metal-air batteries represent promising energy storage devices when supplied with atmospheric air. However, under this condition, the air electrode shows a very short life time (i.e. 50 h of operation in 5 M LiOH at -10 mA cm-2), mainly due to the precipitation of carbonates inside the electrode porosity. The air electrode can then be protected by an anion exchange membrane on the electrolyte side. In this paper, we demonstrate that the efficiency of this protective membrane depends on the assembly method on the electrode. When a modified poly(epichlorohydrin) (PECH) network is synthesized directly on the electrode, the polymer seeps inside the electrode porosity, and a suitable interface inducing negligible additional polarization in comparison with classical pressure-assembled membranes is obtained. This protected electrode shows improved stability of up to 160 h of operation in 5 M LiOH. This performance is improved to 350 h by adjusting the conductivity and the ionic exchange capacity. Finally, the interest of interpenetrating polymer network (IPN) architecture compared to a single network is confirmed. Indeed, an electrode protected with a PECH/poly(2-hydroxyethyl methacrylate) (PHEMA) IPN is stable for 650 h in 5 M LiOH. In addition, degradation process becomes reversible since the assembly can be regenerated, which is not possible for the bare electrode.

  12. Particle impactor assembly for size selective high volume air sampler

    DOEpatents

    Langer, Gerhard

    1988-08-16

    Air containing entrained particulate matter is directed through a plurality of parallel, narrow, vertically oriented impactor slots of an inlet element toward an adjacently located, relatively large, dust impaction surface preferably covered with an adhesive material. The air flow turns over the impaction surface, leaving behind the relatively larger particles according to the human thoracic separation system and passes through two elongate exhaust apertures defining the outer bounds of the impaction collection surface to pass through divergent passages which slow down and distribute the air flow, with entrained smaller particles, over a fine filter element that separates the fine particles from the air. The elongate exhaust apertures defining the impaction collection surface are spaced apart by a distance greater than the lengths of elongate impactor slots in the inlet element and are oriented to be normal thereto. By appropriate selection of dimensions and the number of impactor slots air flow through the inlet element is provided a nonuniform velocity distribution with the lower velocities being obtained near the center of the impactor slots, in order to separate out particles larger than a certain predetermined size on the impaction collection surface. The impaction collection surface, even in a moderately sized apparatus, is thus relatively large and permits the prolonged sampling of air for periods extending to four weeks.

  13. Air Conditioning. Trade and Industrial Education Trade Preparatory Training Guide.

    ERIC Educational Resources Information Center

    Nebraska State Dept. of Education, Lincoln. Div. of Vocational Education.

    One of a series of curriculum guides prepared for the building occupations cluster of the construction/fabrication occupational group, this guide identifies the essentials of the air conditioning trade as recommended by the successful air conditioner. An instructional program based upon the implementation of the guide is expected to prepare a…

  14. The Sensing Technology for Air-Conditioning Equipments

    NASA Astrophysics Data System (ADS)

    Matsuzaka, Takashi

    Various kinds of sensor are used for control of air-conditioning equipments. In this paper, examples of control system using some kinks of sensor about improvement of amenity are introduced. Humidity control methods using ceramic humidity sonsor, temperature-radiation-air flow control methods using amenity sensor, zone control methods using human detecting sensor and IAQ control methods using gas sensor, are discussed.

  15. Specific features of operation of a membrane-electrode assembly of an air-hydrogen fuel cell

    NASA Astrophysics Data System (ADS)

    Nechitailov, A. A.; Glebova, N. V.; Koshkina, D. V.; Tomasov, A. A.; Zelenina, N. K.; Terukova, E. E.

    2013-09-01

    Specific features of the operation of the membrane-electrode assembly with high catalytic activity that are a part of the simplified design of a low-temperature air-hydrogen fuel cell under conditions of forced and natural convection of air on the cathode are studied. The governing effect of water balance on the specific power of the fuel cell in the stationary mode (˜1 h) is shown, and the range of the operating conditions of the cell with self-control is determined. The power of the fuel cell at an efficiency of ˜50% and the surface density of platinum on a cathode of ≈0.2 mg/cm2 is 200-250 and 100 mW/cm2 in the forced and natural air-convection modes, respectively, which is comparable with the advanced results.

  16. Extreme conditions in a dissolving air nanobubble.

    PubMed

    Yasui, Kyuichi; Tuziuti, Toru; Kanematsu, Wataru

    2016-07-01

    Numerical simulations of the dissolution of an air nanobubble in water have been performed taking into account the effect of bubble dynamics (inertia of the surrounding liquid). The presence of stable bulk nanobubbles is not assumed in the present study because the bubble radius inevitably passes the nanoscale in the complete dissolution of a bubble. The bubble surface is assumed to be clean because attachment of hydrophobic materials on the bubble surface could considerably change the gas diffusion rate. The speed of the bubble collapse (the bubble wall speed) increases to about 90 m/s or less. The shape of a bubble is kept nearly spherical because the amplitude of the nonspherical component of the bubble shape is negligible compared to the instantaneous bubble radius. In other words, a bubble never disintegrates into daughter bubbles during the dissolution. At the final moment of the dissolution, the temperature inside a bubble increases to about 3000 K due to the quasiadiabatic compression. The bubble temperature is higher than 1000 K only for the final 19 ps. However, the Knudsen number is more than 0.2 for this moment, and the error associated with the continuum model should be considerable. In the final 2.3 ns, only nitrogen molecules are present inside a bubble as the solubility of nitrogen is the lowest among the gas species. The radical formation inside a bubble is negligible because the probability of nitrogen dissociation is only on the order of 10^{-15}. The pressure inside a bubble, as well as the liquid pressure at the bubble wall, increases to about 5 GPa at the final moment of dissolution. The pressure is higher than 1 GPa for the final 0.7 ns inside a bubble and for the final 0.6 ns in the liquid at the bubble wall. The liquid temperature at the bubble wall increases to about 360 K from 293 K at the final stage of the complete dissolution. PMID:27575216

  17. Extreme conditions in a dissolving air nanobubble

    NASA Astrophysics Data System (ADS)

    Yasui, Kyuichi; Tuziuti, Toru; Kanematsu, Wataru

    2016-07-01

    Numerical simulations of the dissolution of an air nanobubble in water have been performed taking into account the effect of bubble dynamics (inertia of the surrounding liquid). The presence of stable bulk nanobubbles is not assumed in the present study because the bubble radius inevitably passes the nanoscale in the complete dissolution of a bubble. The bubble surface is assumed to be clean because attachment of hydrophobic materials on the bubble surface could considerably change the gas diffusion rate. The speed of the bubble collapse (the bubble wall speed) increases to about 90 m/s or less. The shape of a bubble is kept nearly spherical because the amplitude of the nonspherical component of the bubble shape is negligible compared to the instantaneous bubble radius. In other words, a bubble never disintegrates into daughter bubbles during the dissolution. At the final moment of the dissolution, the temperature inside a bubble increases to about 3000 K due to the quasiadiabatic compression. The bubble temperature is higher than 1000 K only for the final 19 ps. However, the Knudsen number is more than 0.2 for this moment, and the error associated with the continuum model should be considerable. In the final 2.3 ns, only nitrogen molecules are present inside a bubble as the solubility of nitrogen is the lowest among the gas species. The radical formation inside a bubble is negligible because the probability of nitrogen dissociation is only on the order of 10-15. The pressure inside a bubble, as well as the liquid pressure at the bubble wall, increases to about 5 GPa at the final moment of dissolution. The pressure is higher than 1 GPa for the final 0.7 ns inside a bubble and for the final 0.6 ns in the liquid at the bubble wall. The liquid temperature at the bubble wall increases to about 360 K from 293 K at the final stage of the complete dissolution.

  18. Extreme conditions in a dissolving air nanobubble.

    PubMed

    Yasui, Kyuichi; Tuziuti, Toru; Kanematsu, Wataru

    2016-07-01

    Numerical simulations of the dissolution of an air nanobubble in water have been performed taking into account the effect of bubble dynamics (inertia of the surrounding liquid). The presence of stable bulk nanobubbles is not assumed in the present study because the bubble radius inevitably passes the nanoscale in the complete dissolution of a bubble. The bubble surface is assumed to be clean because attachment of hydrophobic materials on the bubble surface could considerably change the gas diffusion rate. The speed of the bubble collapse (the bubble wall speed) increases to about 90 m/s or less. The shape of a bubble is kept nearly spherical because the amplitude of the nonspherical component of the bubble shape is negligible compared to the instantaneous bubble radius. In other words, a bubble never disintegrates into daughter bubbles during the dissolution. At the final moment of the dissolution, the temperature inside a bubble increases to about 3000 K due to the quasiadiabatic compression. The bubble temperature is higher than 1000 K only for the final 19 ps. However, the Knudsen number is more than 0.2 for this moment, and the error associated with the continuum model should be considerable. In the final 2.3 ns, only nitrogen molecules are present inside a bubble as the solubility of nitrogen is the lowest among the gas species. The radical formation inside a bubble is negligible because the probability of nitrogen dissociation is only on the order of 10^{-15}. The pressure inside a bubble, as well as the liquid pressure at the bubble wall, increases to about 5 GPa at the final moment of dissolution. The pressure is higher than 1 GPa for the final 0.7 ns inside a bubble and for the final 0.6 ns in the liquid at the bubble wall. The liquid temperature at the bubble wall increases to about 360 K from 293 K at the final stage of the complete dissolution.

  19. 64. INTERIOR VIEW LOOKING DOWN LENGTH OF AIR CONDITIONING EQUIPMENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    64. INTERIOR VIEW LOOKING DOWN LENGTH OF AIR CONDITIONING EQUIPMENT REPAIR SHOP. - Baltimore & Ohio Railroad, Mount Clare Shops, South side of Pratt Street between Carey & Poppleton Streets, Baltimore, Independent City, MD

  20. 10. Building 105, Facilities Engineering Building, 1830, interior, air condition ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Building 105, Facilities Engineering Building, 1830, interior, air condition repair shop, S end of building, looking N. - Watervliet Arsenal, Building 105, South Broadway, on Hudson River, Watervliet, Albany County, NY

  1. Application of solar energy to air conditioning systems

    NASA Technical Reports Server (NTRS)

    Nash, J. M.; Harstad, A. J.

    1976-01-01

    The results of a survey of solar energy system applications of air conditioning are summarized. Techniques discussed are both solar powered (absorption cycle and the heat engine/Rankine cycle) and solar related (heat pump). Brief descriptions of the physical implications of various air conditioning techniques, discussions of status, proposed technological improvements, methods of utilization and simulation models are presented, along with an extensive bibliography of related literature.

  2. The microbiological quality of air improves when using air conditioning systems in cars

    PubMed Central

    2010-01-01

    Background Because of better comfort, air conditioning systems are a common feature in automobiles these days. However, its impact on the number of particles and microorganisms inside the vehicle - and by this its impact on the risk of an allergic reaction - is yet unknown. Methods Over a time period of 30 months, the quality of air was investigated in three different types of cars (VW Passat, VW Polo FSI, Seat Alhambra) that were all equipped with a automatic air conditioning system. Operation modes using fresh air from outside the car as well as circulating air from inside the car were examined. The total number of microorganisms and the number of mold spores were measured by impaction in a high flow air sampler. Particles of 0.5 to 5.0 μm diameter were counted by a laser particle counter device. Results Overall 32 occasions of sampling were performed. The concentration of microorganisms outside the cars was always higher than it was inside the cars. Few minutes after starting the air conditioning system the total number of microorganisms was reduced by 81.7%, the number of mold spores was reduced by 83.3%, and the number of particles was reduced by 87.8%. There were no significant differences neither between the types of cars nor between the types of operation mode of the air conditioning system (fresh air vs. circulating air). All parameters that were looked for in this study improved during utilization of the car's air conditioning system. Conclusions We believe that the risk of an allergic reaction will be reduced during use also. Nevertheless, we recommend regular maintenance of the system and replacement of older filters after defined changing intervals. PMID:20515449

  3. Impact of Air-Filter Condition on HVAC Equipment

    SciTech Connect

    Jung, L.

    1987-01-01

    An analysis was performed of changes in energy consumption caused by dirty filters for heating, ventilation, and air-conditioning systems during both heating and cooling cycles. Basic heat-transfer fundamentals and the vapor-compression refrigeration cycle for air conditioners were used. The energy cost savings between a dirty and a clean filter were small and were mainly offset by the filter cost. However, the consequences of deferring filter replacement could be very costly because of early equipment failures.

  4. Duct System Flammability and Air Sealing Fire Separation Assemblies in the International Residential Code

    SciTech Connect

    Rudd, A.; Prahl, D.

    2014-12-01

    IBACOS identified two barriers that limit the ability of builders to cost-effectively achieve higher energy efficiency levels in housing. These are the use of duct system materials that inherently achieve airtightness and are appropriately sized for low-load houses and the ability to air seal fire separation assemblies. The issues identified fall into a gray area of the codes.

  5. Duct System Flammability and Air Sealing Fire Separation Assemblies in the International Residential Code

    SciTech Connect

    Rudd, A.; Prahl, D.

    2014-12-01

    IBACOS identified two barriers that limit the ability of builders to cost-effectively achieve higher energy efficiency levels in housing. These are (1) the use of duct system materials that inherently achieve airtightness and are appropriately sized for low-load houses and (2) the ability to air seal fire separation assemblies. The issues identified fall into a gray area of the codes.

  6. Ground performance of air conditioning and water recycle system for a space plant box

    NASA Astrophysics Data System (ADS)

    Tani, A.; Okuma, T.; Goto, E.; Kitaya, Y.; Saito, T.; Takahashi, H.

    Researchers from 5 Japanese universities have developed a plant growth facility (Space Plant Box) for seed to seed experiments under microgravity. The breadboard model of the Space Plant Box was fabricated by assembling subsystems developed for microgravity. The subsystems include air conditioning and water recycle system, air circulation system, water and nutrient delivery system, lighting system and plant monitoring system. The air conditioning and water recycle system is simply composed of a single heat exchanger, two fans and hydrophilic fibrous strings. The strings allow water movement from the cooler fin in the Cooling Box to root supporting materials in the Plant Growth Chamber driven by water potential deficit. Relative humidity in the Plant Growth Chamber can be changed over a wide range by controlling the ratio of latent heat exchange to sensible heat exchange on the cooling fin of the heat exchanger. The transpiration rate was successfully measured by circulating air inside the Plant Growth Chamber only. Most water was recycled and a small amount of water needed to be added from the outside. The simple, air conditioning and water recycle system for the Space Plant Box showed good performance through a barley ( Hordeum vulgare L.) growth experiment.

  7. Ground performance of air conditioning and water recycle system for a Space Plant Box.

    PubMed

    Tani, A; Okuma, T; Goto, E; Kitaya, Y; Saito, T; Takahashi, H

    2001-01-01

    Researchers from 5 Japanese universities have developed a plant growth facility (Space Plant Box) for seed to seed experiments under microgravity. The breadboard model of the Space Plant Box was fabricated by assembling subsystems developed for microgravity. The subsystems include air conditioning and water recycle system, air circulation system, water and nutrient delivery system, lighting system and plant monitoring system. The air conditioning and water recycle system is simply composed of a single heat exchanger, two fans and hydrophilic fibrous strings. The strings allow water movement from the cooler fin in the Cooling Box to root supporting materials in the Plant Growth Chamber driven by water potential deficit. Relative humidity in the Plant Growth Chamber can be changed over a wide range by controlling the ratio of latent heat exchange to sensible heat exchange on the cooling fin of the heat exchanger. The transpiration rate was successfully measured by circulating air inside the Plant Growth Chamber only. Most water was recycled and a small amount of water needed to be added from the outside. The simple, air conditioning and water recycle system for the Space Plant Box showed good performance through a barley (Hordeum vulgare L.) growth experiment.

  8. Development of the anode bipolar plate/membrane assembly unit for air breathing PEMFC stack using silicone adhesive bonding

    NASA Astrophysics Data System (ADS)

    Kim, Minkook; Lee, Dai Gil

    2016-05-01

    Polymer electrolyte membrane fuel cells (PEMFC) exhibit a wide power range, low operating temperature, high energy density and long life time. These advantages favor PEMFC for applications such as vehicle power sources, portable power, and backup power applications. With the push towards the commercialization of PEMFC, especially for portable power applications, the overall balance of plants (BOPs) of the systems should be minimized. To reduce the mass and complexity of the systems, air-breathing PEMFC stack design with open cathode channel configuration is being developed. However, the open cathode channel configuration incurs hydrogen leakage problem. In this study, the bonding strength of a silicon adhesive between the Nafion membrane and the carbon fiber/epoxy composite bipolar plate was measured. Then, an anode bipolar plate/membrane assembly unit which was bonded with the silicone adhesive was developed to solve the hydrogen leakage problem. The reliability of the anode bipolar plate/membrane assembly unit was estimated under the internal pressure of hydrogen by the FE analysis. Additionally, the gas sealability of the developed air breathing PEMFC unit cell was experimentally measured. Finally, unit cell performance of the developed anode bipolar plate/membrane assembly unit was tested and verified under operating conditions without humidity and temperature control.

  9. Study of long term options for electric vehicle air conditioning

    SciTech Connect

    Dieckmann, J.; Mallory, D. , Inc., Cambridge, MA )

    1991-07-01

    There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an [open quotes]upsized[close quotes] condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.

  10. Study of long term options for electric vehicle air conditioning

    SciTech Connect

    Dieckmann, J.; Mallory, D.

    1991-07-01

    There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an {open_quotes}upsized{close_quotes} condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.

  11. Air Conditioning, Heating, and Refrigeration: Scope and Sequence.

    ERIC Educational Resources Information Center

    Nashville - Davidson County Metropolitan Public Schools, TN.

    This scope and sequence guide, developed for an air conditioning, heating, and refrigeration vocational education program, represents an initial step in the development of a systemwide articulated curriculum sequence for all vocational programs within the Metropolitan Nashville Public School System. It was developed as a result of needs expressed…

  12. Heating, Air-Conditioning, and Refrigeration Technician. National Skill Standards.

    ERIC Educational Resources Information Center

    Vocational Technical Education Consortium of States, Decatur, GA.

    This guide contains information on the knowledge and skills identified by industry as essential to the job performance of heating, air-conditioning, and refrigeration technicians. It is intended to assist training providers in public and private institutions, as well as in industry, to develop and implement training that will provide workers with…

  13. An Analysis of the Air Conditioning, Refrigerating and Heating Occupation.

    ERIC Educational Resources Information Center

    Frass, Melvin R.; Krause, Marvin

    The general purpose of the occupational analysis is to provide workable, basic information dealing with the many and varied duties performed in the air conditioning, refrigerating, and heating occupation. The document opens with a brief introduction followed by a job description. The bulk of the document is presented in table form. Six duties are…

  14. Air Conditioning, Heating, and Refrigeration. Competency-Based Curriculum Manual.

    ERIC Educational Resources Information Center

    Gourley, Frank A., Jr.

    This manual was developed to serve as an aid to administrators and instructors involved with postsecondary air conditioning, heating, and refrigeration programs. The first of six chapters contains general information on program implementation, the curriculum design, facilities and equipment requirements, and textbooks and references. Chapter 2…

  15. State Skill Standards: Heating, Ventilation, Air Conditioning, and Refrigeration

    ERIC Educational Resources Information Center

    Ball, Larry; Soukup, Dennis

    2006-01-01

    The Department of Education has undertaken an ambitious effort to develop statewide career and technical education skill standards. The standards in this document are for Heating, Ventilation, Air Conditioning and Refrigeration (HVAC&R) programs and are designed to clearly state what the student should know and be able to do upon completion of an…

  16. Heating, Ventilating, and Air Conditioning. Energy Technology Series.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This course in heating, ventilating, and air conditioning is one of 16 courses in the Energy Technology Series developed for an Energy Conservation-and-Use Technology curriculum. Intended for use in two-year postsecondary technical institutions to prepare technicians for employment, the courses are also useful in industry for updating employees in…

  17. Modelling and simulation of air-conditioning cycles

    NASA Astrophysics Data System (ADS)

    Rais, Sandi; Kadono, Yoshinori; Murayama, Katsunori; Minakuchi, Kazuya; Takeuchi, Hisae; Hasegawa, Tatsuya

    2016-05-01

    The heat-pump cycle for air conditioning was investigated both numerically and experimentally by evaluating the coefficient of performance (COP) under Japanese Industrial Standard (JIS B 8619:1999) and ANSI/AHRI standard 750-2007 operating conditions. We used two expansion valve coefficients Cv_{(\\varphi )} = 0.12 for standard operating conditions (Case 1) approaching 1.3 MPa at high pressure and 0.2 MPa at low pressure, and Cv_{(\\varphi )} = 0.06 namely poor operating conditions (Case 2). To improve the performance of the air conditioner, we compared the performance for two outside air temperatures, 35 and 40 °C (Case 3). The simulation and experiment comparison resulted the decreasing of the COP for standard operating condition is equal to 14 %, from 3.47 to 2.95 and a decrease of the cooling capacity is equal to 18 %, from 309.72 to 253.53 W. This result was also occurred in poor operating condition which the COP was superior at 35 °C temperature.

  18. Effects of air temperature, humidity, and air movement on thermal comfort under hot and humid conditions

    SciTech Connect

    Tanabe, Shinichi; Kimura, Kenichi

    1994-12-31

    The purpose of this paper is to review and summarize the effects of air temperature, humidity, and air movement on thermal comfort under hot and humid conditions with a view toward energy conservation. Recently, ASHRAE published a new comfort envelope in Standard 55-1992. In that standard, the upper limit of relative humidity (RH) was wet at 60%. In hot and humid regions, humidity levels higher than 60% may often be observed. This upper limit of humidity is discussed based on their subjective data. In addition, the results show that under hot and humid conditions, air movement may be one of the least expensive methods of providing thermal comfort. The effect of air movement is also described in this paper.

  19. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System.

    PubMed

    Zhao, Baiwang; Peng, Na; Liang, Canzeng; Yong, Wai Fen; Chung, Tai-Shung

    2015-01-01

    In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18-22 g/m³ to a range of 13.5-18.3 g/m³. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process. PMID:26580660

  20. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System.

    PubMed

    Zhao, Baiwang; Peng, Na; Liang, Canzeng; Yong, Wai Fen; Chung, Tai-Shung

    2015-11-16

    In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18-22 g/m³ to a range of 13.5-18.3 g/m³. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  1. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System

    PubMed Central

    Zhao, Baiwang; Peng, Na; Liang, Canzeng; Yong, Wai Fen; Chung, Tai-Shung

    2015-01-01

    In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18–22 g/m3 to a range of 13.5–18.3 g/m3. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process. PMID:26580660

  2. A strategy for oxygen conditioning at high altitude: comparison with air conditioning.

    PubMed

    West, John B

    2015-09-15

    Large numbers of people live or work at high altitude, and many visit to trek or ski. The inevitable hypoxia impairs physical working capacity, and at higher altitudes there is also cognitive impairment. Twenty years ago oxygen enrichment of room air was introduced to reduce the hypoxia, and this is now used in dormitories, hotels, mines, and telescopes. However, recent advances in technology now allow large amounts of oxygen to be obtained from air or cryogenic oxygen sources. As a result it is now feasible to oxygenate large buildings and even institutions such as hospitals. An analogy can be drawn between air conditioning that has improved the living and working conditions of millions of people who live in hot climates and oxygen conditioning that can do the same at high altitude. Oxygen conditioning is similar to air conditioning except that instead of cooling the air, the oxygen concentration is raised, thus reducing the equivalent altitude. Oxygen conditioning on a large scale could transform living and working conditions at high altitude, where it could be valuable in homes, hospitals, schools, dormitories, company headquarters, banks, and legislative settings.

  3. A strategy for oxygen conditioning at high altitude: comparison with air conditioning.

    PubMed

    West, John B

    2015-09-15

    Large numbers of people live or work at high altitude, and many visit to trek or ski. The inevitable hypoxia impairs physical working capacity, and at higher altitudes there is also cognitive impairment. Twenty years ago oxygen enrichment of room air was introduced to reduce the hypoxia, and this is now used in dormitories, hotels, mines, and telescopes. However, recent advances in technology now allow large amounts of oxygen to be obtained from air or cryogenic oxygen sources. As a result it is now feasible to oxygenate large buildings and even institutions such as hospitals. An analogy can be drawn between air conditioning that has improved the living and working conditions of millions of people who live in hot climates and oxygen conditioning that can do the same at high altitude. Oxygen conditioning is similar to air conditioning except that instead of cooling the air, the oxygen concentration is raised, thus reducing the equivalent altitude. Oxygen conditioning on a large scale could transform living and working conditions at high altitude, where it could be valuable in homes, hospitals, schools, dormitories, company headquarters, banks, and legislative settings. PMID:26139219

  4. Influence of indoor air quality (IAQ) objectives on air-conditioned offices in Hong Kong.

    PubMed

    Hui, Pui-Shan; Mui, Kwok-Wai; Wong, Ling-Tim

    2008-09-01

    It is costly to sample all air pollutants of a general community. Air sampling should be conducted based on a practical assessment strategy and monitoring plan. In Hong Kong, the Environmental Protection Department (HKEPD) launched an Indoor Air Quality (IAQ) certification scheme to grade workplace IAQ as 'Excellent' or 'Good' by measuring the levels of nine common indoor air pollutants, namely carbon dioxide (CO(2)), carbon monoxide (CO), respirable suspended particulates (RSP), nitrogen dioxide (NO(2)), ozone (O(3)), formaldehyde (HCHO), total volatile organic compounds (TVOC), radon (Rn), and airborne bacteria count (ABC). Although average office IAQ performance has been improved since the implementation of this certification scheme, there are still resource issues and technical difficulties. To streamline the assessment of office IAQ performance, this study proposes a simple index of IAQ benchmarks formulated in compliance with the HKEPD requirements. In particular, three of the nine listed common air pollutants were selected as the 'representatives' for the overall satisfactory IAQ. Together with the assessment results of 422 Hong Kong air-conditioned offices, the index was evaluated in terms of test sensitivity, specificity and predictive values. Proved to be feasible to describe the IAQ of some air-conditioned offices, this IAQ index would be a useful tool for policymakers, building owners and professionals to quantify IAQ performance in offices and to make decisions on resources and manpower management for efficient mitigation actions.

  5. TEWI Evaluation for Household Refrigeration and Air-Conditioning Systems

    NASA Astrophysics Data System (ADS)

    Sobue, Atsushi; Watanabe, Koichi

    In the present study, we have quantitatively evaluated the global warming impact by household refrigerator and air-conditioning systems on the basis of reliable TEWI information. In TEWI evaluation of household refrigerators, the percentage of the impact by refrigerant released to the atmosphere (direct effect) is less than 18.6% in TEWI. In case of room air-conditioners, however, the percentage of direct effect is less than 5.4% in TEWI. Therefore, it was confirmed that impact by CO2 released as a result of the energy consumed to drive the refrigeration or air-conditioning systems throughout their lifetime (indirect effect) is far larger than direct effect by the entire system. A reduction of indirect effect by energy saving is the most effective measure in reducing the global warming impact by refrigeration and air-conditioning systems, For a realization of the energy saving, not only the advanced improvement in energy efficiency by household appliance manufacturers but also the improvement of consumer's mind in selecting the systems and a way of using are concluded important.

  6. Do residential air-conditioning rebates miss the mark?

    SciTech Connect

    Stickney, B.; Shepard, M.

    1994-12-31

    The rebates utilities provide for residential central air conditioners and heat pumps to encourage improved cooling efficiency may inadvertently reward higher peak demand in many cases. This problem could be avoided by using both efficiency and peak performance to determine eligibility for rebates. Such changes to incentive formulas would better align the utilities` DSM programs with the dual goals of improved efficiency and peak demand reduction. Improved peak performance would be especially advantageous for sunbelt utilities whose residential cooling load is highly coincident with the summer peak. Air conditioning has been called the utilities` ``load from hell,`` because it is intermittent, unpredictable, and is the largest contributor to summer peak demand, requiring massive investments in power generation and delivery capacity. It is no wonder then that more DSM programs are targeted at space cooling than at any other end use. Ironically, however, all of the residential rebate programs the authors examined for central air conditioners and heat pumps are based on the seasonal energy efficiency ratio (SEER), which provides a valuable measure of seasonal energy efficiency but is not a good indicator of peak demand. Residential central air conditioning incentive programs for eight major utilities are based exclusively on SEER and most ratchet up the incentive levels with increasing SEER. None include the measure for peak demand for residential cooling equipment, which is the so-called energy efficiency ratio, or EER.

  7. [Air conditioning units and warm air blankets in the operating room].

    PubMed

    Kerwat, Klaus; Piechowiak, Karolin; Wulf, Hinnerk

    2013-01-01

    Nowadays almost all operating rooms are equipped with air conditioning (AC units). Their main purpose is climatization, like ventilation, moisturizing, cooling and also the warming of the room in large buildings. In operating rooms they have an additional function in the prevention of infections, especially the avoidance of postoperative wound infections. This is achieved by special filtration systems and by the creation of specific air currents. Since hypothermia is known to be an unambiguous factor for the development of postoperative wound infections, patients are often actively warmed intraoperatively using warm air blankets (forced-air warming units). In such cases it is frequently discussed whether such warm air blankets affect the performance of AC units by changing the air currents or whether, in contrast, have exactly the opposite effect. However, it has been demonstrated in numerous studies that warm air blankets do not have any relevant effect on the functioning of AC units. Also there are no indications that their use increases the rate of postoperative wound infections. By preventing the patient from experiencing hypothermia, the rate of postoperative wound infections can even be decreased thereby.

  8. Solar air-conditioning-active, hybrid and passive

    SciTech Connect

    Yellott, J. I.

    1981-04-01

    After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)

  9. Methane and air mixing times under nonreacting and reacting conditions

    SciTech Connect

    Brasoveanu, D.; Gupta, A.K.

    1996-12-31

    Mixing times of methane and air under nonreacting or reacting conditions in the presence of a constant rate of temperature or pressure are examined using a mixing model based on the ideal gas law and the equation of continuity. The model is valid for low pressure ratios combustors under nonreacting conditions. The model is also valid under reacting conditions for the fresh mixture which contains only trace amounts of combustion products. The effects of initial pressure, temperature, velocity divergence and initial fluid composition on mixing time are also analyzed. Results show that under both reacting and nonreacting conditions, the mixing time is directly proportional to the initial pressure and temperature of mixture and inversely proportional to rates of pressure and temperature and to the velocity divergence. The mixing time is shorter for the case of fuel dispersing into the surrounding air, than for the case of air penetrating into the fuel flow. The rates of pressure of less than 1 atm/s alone can provide a mixing time in excess of one second which is unacceptably long for many applications, in particular gas turbine combustion. Rates of temperature produced by flame may provide mixing times of less than 0.1 s. To assure mixing times of a few milliseconds for efficient combustion, coupled with low pollutants emission, high velocity gradients between the fuel and air flows are required. The results show that a combination of several effects must be used in parallel for achieving this goal. This analysis of mixing time is intended to provide important design guidelines for the development of high intensity and high efficiency combustors having low pollutants emission.

  10. High Technology Centrifugal Compressor for Commercial Air Conditioning Systems

    SciTech Connect

    Ruckes, John

    2006-04-15

    R&D Dynamics, Bloomfield, CT in partnership with the State of Connecticut has been developing a high technology, oil-free, energy-efficient centrifugal compressor called CENVA for commercial air conditioning systems under a program funded by the US Department of Energy. The CENVA compressor applies the foil bearing technology used in all modern aircraft, civil and military, air conditioning systems. The CENVA compressor will enhance the efficiency of water and air cooled chillers, packaged roof top units, and other air conditioning systems by providing an 18% reduction in energy consumption in the unit capacity range of 25 to 350 tons of refrigeration The technical approach for CENVA involved the design and development of a high-speed, oil-free foil gas bearing-supported two-stage centrifugal compressor, CENVA encompassed the following high technologies, which are not currently utilized in commercial air conditioning systems: Foil gas bearings operating in HFC-134a; Efficient centrifugal impellers and diffusers; High speed motors and drives; and System integration of above technologies. Extensive design, development and testing efforts were carried out. Significant accomplishments achieved under this program are: (1) A total of 26 builds and over 200 tests were successfully completed with successively improved designs; (2) Use of foil gas bearings in refrigerant R134a was successfully proven; (3) A high speed, high power permanent magnet motor was developed; (4) An encoder was used for signal feedback between motor and controller. Due to temperature limitations of the encoder, the compressor could not operate at higher speed and in turn at higher pressure. In order to alleviate this problem a unique sensorless controller was developed; (5) This controller has successfully been tested as stand alone; however, it has not yet been integrated and tested as a system; (6) The compressor successfully operated at water cooled condensing temperatures Due to temperature

  11. Effect of Intake Air Filter Condition on Vehicle Fuel Economy

    SciTech Connect

    Norman, Kevin M; Huff, Shean P; West, Brian H

    2009-02-01

    The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oil and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a study aimed specifically at the effect of engine air filter condition on fuel economy. The goal of this study was to explore the effects of a clogged air filter on the fuel economy of vehicles operating over prescribed test cycles. Three newer vehicles (a 2007 Buick Lucerne, a 2006 Dodge Charger, and a 2003 Toyota Camry) and an older carbureted vehicle were tested. Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in

  12. In-Cab Air Quality of Trucks Air Conditioned and Kept in Electrified Truck Stop

    SciTech Connect

    Lee, Doh-Won; Zietsman, Josias; Farzaneh, Mohamadreza; Li, Wen-Whai; Olvera, Hector; Storey, John Morse; Kranendonk, Laura

    2009-01-01

    At night, long-haul truck drivers rest inside the cabins of their vehicles. Therefore, the in-cab air quality while air conditioning (A/C) is being provided can be a great concern to the drivers health. The effect of using different A/C methods [truck's A/C, auxiliary power unit (APU), and truck stop electrification (TSE) unit] on in-cab air quality of a heavy-duty diesel vehicle was investigated at an electrified truck stop in the El Paso, Texas, area. The research team measured the in-cabin and the ambient air quality adjacent to the parked diesel truck as well as emissions from the truck and an APU while it was providing A/C. The measured results were compared and analyzed. On the basis of these results, it was concluded that the TSE unit provided better in-cab air quality while supplying A/C. Furthermore, the truck and APU exhaust emissions were measured, and fuel consumption of the truck (while idling) and the APU (during operation) were compared. The results led to the finding that emissions from the APU were less than those from the truck's engine idling, but the APU consumed more fuel than the engine while providing A/C under given conditions.

  13. Structural Design and Preliminary Evaluation of a Lightweight, Brazed, Air-Cooled Turbine Rotor Assembly

    NASA Technical Reports Server (NTRS)

    Meyer, Andre J., Jr.; Morgan, William C.

    1958-01-01

    A lightweight turbine rotor assembly was devised, and components were evaluated in a full-scale jet engine. Thin sheet-metal airfoils were brazed to radial fingers that were an integral part of a number of thin disks composing the turbine rotor. Passages were provided between the disks and in the blades for air cooling. The computed weight of the assembly was 50 percent less than that of a similar turbine of normal construction used in a conventional turbojet engine. Two configurations of sheet-metal test blades simulating the manner of attachment were fabricated and tested in a turbojet engine at rated speed and temperature. After 8-1/2 hours of operation pieces broke loose from the tip sections of the better blades. Severe cracking produced by vibration was determined as the cause of failure. Several methods of overcoming the vibration problem are suggested.

  14. Do-It-Yourself Additives Recharge Auto Air Conditioning

    NASA Technical Reports Server (NTRS)

    2010-01-01

    In planning for a return mission to the Moon, NASA aimed to improve the thermal control systems that keep astronauts comfortable and cool while inside a spacecraft. Goddard Space Flight Center awarded a Small Business Innovation Research (SBIR) contract to Mainstream Engineering Corporation, of Rockledge, Florida, to develop a chemical/mechanical heat pump. IDQ Inc., of Garland, Texas, exclusively licensed the technology and incorporates it into its line of Arctic Freeze products for automotive air conditioning applications. While working on the design, Mainstream Engineering came up with a unique liquid additive called QwikBoost to enhance the performance of the advanced heat pump design.

  15. Investigation of air cleaning system response to accident conditions

    SciTech Connect

    Andrae, R.W.; Bolstad, J.W.; Foster, R.D.; Gregory, W.S.; Horak, H.L.; Idar, E.S.; Martin, R.A.; Ricketts, C.I.; Smith, P.R.; Tang, P.K.

    1980-01-01

    Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported.

  16. Analysis of non-CFC automotive air conditioning

    SciTech Connect

    Mei, V.C.; Chen, F.C. ); Sullivan, R.A. )

    1991-01-01

    Concern about the destruction of the global environment by chlorofluorocarbon (CFC) fluids has become an impetus in searching for alternative non-CFC refrigerants and cooling methods for mobile air conditioning (MAC). While some alternative refrigerants have been identified, they are not considered a lasting solution because of their high global warming potential (GWP), which could result in their eventual phase-out. In view of this dilemma, environmentally acceptable alternative cooling methods have become important. This study discusses the advantages and the limits of some of the alternative automotive cooling methodologies. 19 refs., 6 figs.

  17. Liquid over-feeding air conditioning system and method

    DOEpatents

    Mei, V.C.; Chen, F.C.

    1993-09-21

    A refrigeration air conditioning system utilizing a liquid over-feeding operation is described. A liquid refrigerant accumulator-heat exchanger is placed in the system to provide a heat exchange relationship between hot liquid refrigerant discharged from condenser and a relatively cool mixture of liquid and vaporous refrigerant discharged from the evaporator. This heat exchange relationship substantially sub-cools the hot liquid refrigerant which undergoes little or no evaporation across the expansion device and provides a liquid over-feeding operation through the evaporator for effectively using 100 percent of evaporator for cooling purposes and for providing the aforementioned mixture of liquid and vaporous refrigerant. 1 figure.

  18. Liquid over-feeding air conditioning system and method

    DOEpatents

    Mei, Viung C.; Chen, Fang C.

    1993-01-01

    A refrigeration air conditioning system utilizing a liquid over-feeding operation is described. A liquid refrigerant accumulator-heat exchanger is placed in the system to provide a heat exchange relationship between hot liquid refrigerant discharged from condenser and a relatively cool mixture of liquid and vaporous refrigerant discharged from the evaporator. This heat exchange relationship substantially sub-cools the hot liquid refrigerant which undergoes little or no evaporation across the expansion device and provides a liquid over-feeding operation through the evaporator for effectively using 100 percent of evaporator for cooling purposes and for providing the aforementioned mixture of liquid and vaporous refrigerant.

  19. On the impact of entrapped air in infiltration under ponding conditions. Part a: Preferential air flow path effects on infiltration

    NASA Astrophysics Data System (ADS)

    Mizrahi, Guy; Weisbrod, Noam; Furman, Alex

    2015-04-01

    Entrapped air effects on infiltration under ponding conditions could be important for massive infiltration of managed aquifer recharge (MAR) or soil aquifer treatment (SAT) of treated wastewater. Earlier studies found that under ponding conditions, air is being entrapped and compressed until it reaches a pressure which will enable the air to escape (unstable air flow). They also found that entrapped air could reduce infiltration by 70-90%. Most studies have dealt with entrapped air effects when soil surface topography is flat. The objective of this study is to investigate, under ponding conditions, the effects of: (1) irregular surface topography on preferential air flow path development (stable air flow); (2) preferential air flow path on infiltration; and (3) hydraulic head on infiltration when air is trapped. Column experiments were used to investigate these particular effects. A 140 cm deep and 30 cm wide column packed with silica sand was used under two boundary conditions: in the first, air can only escape vertically upward through the soil surface; in the second, air is free to escape through 20 ports installed along the column perimeter. The surface was flooded with 13 liters of water, with ponding depth decreasing with time. Two soil surface conditions were tested: flat surface and irregular surface (high and low surface zones). Additionally, Helle-show experiments were conducted in order to obtain a visual observation of preferential air flow path development. The measurements were carried out using a tension meter, air pressure transducers, TDR and video cameras. It was found that in irregular surfaces, stable air flow through preferential paths was developed in the high altitude zones. Flat surface topography caused unstable air flow through random paths. Comparison between irregular and flat surface topography showed that the entrapped air pressure was lower and the infiltration rate was about 40% higher in the irregular surface topography than in the

  20. Control of Computer Room Air Conditioning using IT Equipment Sensors

    SciTech Connect

    Bell, Geoffrey C.; Storey, Bill; Patterson, Michael K.

    2009-09-30

    The goal of this demonstration was to show how sensors in IT equipment could be accessed and used to directly control computer room air conditioning. The data provided from the sensors is available on the IT network and the challenge for this project was to connect this information to the computer room air handler's control system. A control strategy was developed to enable separate control of the chilled water flow and the fans in the computer room air handlers. By using these existing sensors in the IT equipment, an additional control system is eliminated (or could be redundant) and optimal cooling can be provided saving significant energy. Using onboard server temperature sensors will yield significant energy reductions in data centers. Intel hosted the demonstration in its Santa Clara, CA data center. Intel collaborated with IBM, HP, Emerson, Wunderlich-Malec Engineers, FieldServer Technologies, and LBNL to install the necessary components and develop the new control scheme. LBNL also validated the results of the demonstration.

  1. An effective silencer design for artificially air conditioned environment.

    PubMed

    Fujiwara, Kyoji; Pang, Li Feng

    2004-11-01

    An effective silencer for an air conditioning duct is studied. A duct with an acoustically soft boundary is employed as an effective silencer. On the acoustically soft boundary the sound pressure is zero and it is impossible to realize such boundary in the air-borne sound field, because of the non-existence of a much lighter medium than the air. In this study, the arrangement of one-quarter wave-length acoustic tubes is employed as a soft boundary. This acoustic tube has frequency dependence, but the sound pressure becomes nearly zero at the tube mouth around the odd resonance frequency. The relation between the noise reduction efficiency and this acoustically soft boundary is examined experimentally and more than 40 dB noise reduction is obtained in a one-half octave band around the first resonance frequency. It is also made clear that more than one wave length of soft boundary is required to get enough reduction compared with the reduction obtained in the case of quite a long soft boundary.

  2. Bioaerosol deposition on an air-conditioning cooling coil

    NASA Astrophysics Data System (ADS)

    Wu, Yan; Chen, Ailu; Luhung, Irvan; Gall, Elliott T.; Cao, Qingliang; Chang, Victor Wei-Chung; Nazaroff, William W.

    2016-11-01

    This study is concerned with the role of a fin-and-tube heat exchanger in modifying microbial indoor air quality. Specifically, depositional losses of ambient bioaerosols and particles onto dry (not cooled) and wet (cool) coil surfaces were measured for different airspeeds passing through the test coil. Total, bacterial and fungal DNA concentrations in condensate water produced by a wet coil were also quantified by means of fluorescent dsDNA-binding dye and qPCR assays. Results revealed that the deposition of bioaerosols and total particles is substantial on coil surfaces, especially when wet and cool. The average deposition fraction was 0.14 for total DNA, 0.18 for bacterial DNA and 0.22 for fungal DNA on the dry coil, increasing to 0.51 for total DNA, 0.50 for bacterial DNA and 0.68 for fungal DNA on the wet coil. Overall, as expected, deposition fractions increased with increasing particle size and increasing airspeed. Deposited DNA was removed from the cooling coil surfaces through the flow of condensing water at a rate comparable to the rate of direct deposition from air. A downward trend of bacterial and fungal DNA measured in condensate water over time provides suggestive evidence of biological growth on heat exchangers during nonoperational times of a ventilation system. This investigation provides new information about bioaerosol deposition onto a conventional fin-and-tube cooling coil, a potentially important factor influencing indoor exposure to microbial aerosols in air-conditioned buildings.

  3. Absorption and adsorption chillers applied to air conditioning systems

    NASA Astrophysics Data System (ADS)

    Kuczyńska, Agnieszka; Szaflik, Władysław

    2010-07-01

    This work presents an application possibility of sorption refrigerators driven by low temperature fluid for air conditioning of buildings. Thermodynamic models were formulated and absorption LiBr-water chiller with 10 kW cooling power as well as adsorption chiller with silica gel bed were investigated. Both of them are using water for desorption process with temperature Tdes = 80 °C. Coefficient of performance (COP) for both cooling cycles was analyzed in the same conditions of the driving heat source, cooling water Tc = 25 °C and temperature in evaporator Tevap = 5 °C. In this study, the computer software EES was used to investigate the performance of absorption heat pump system and its behaviour in configuration with geothermal heat source.

  4. Guidelines on Thermal Comfort of Air Conditioned Indoor Environment

    NASA Astrophysics Data System (ADS)

    Miura, Toyohiko

    The thermal comfort of air conditioned indoor environment for workers depended, of course, on metabolic rate of work, race, sex, age, clothing, climate of the district and state of acclimatization. The attention of the author was directed to the seasonal variation and the sexual difference of comfortable temperature and a survey through a year was conducted on the thermal comfort, and health conditions of workers engaged in light work in a precision machine factory, in some office workers. Besides, a series of experiments were conducted for purpose of determinning the optimum temperature of cooling in summer time in relation to the outdoor temperature. It seemed that many of workers at present would prefer somewhat higher temperature than those before the World War II. Forty years ago the average homes and offices were not so well heated as today, and clothing worn on the average was considerably heavier.

  5. International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Operation, Recovery, and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Balistreri, Steven F.; Steele, John W.; Caron, Mark E.; Laliberte, Yvon J.; Shaw, Laura A.

    2013-01-01

    The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX in the ISS segments, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the ISS cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings as well as remediation and recovery of the full heat exchanger will be

  6. BiOCl micro-assembles consisting of ultrafine nanoplates: A high performance electro-catalyst for air electrode of Al-air batteries

    NASA Astrophysics Data System (ADS)

    Yuan, Jinlan; Wang, Jin; She, Yiyi; Hu, Jing; Tao, Pengpeng; Lv, Fucong; Lu, Zhouguang; Gu, Yingying

    2014-10-01

    BiOCl micro-assembles appearing spherical and plate-like in shape consisting of ultrafine nanoplates were successfully synthesized by a simple hydrothermal method. The obtained BiOCl micro-assembles were characterized as oxygen reduction reaction (ORR) catalyst for air electrode of aluminum air batteries by using linear polarization and constant-current discharge techniques. The effect of precursor concentration on the electrochemical properties of the air electrodes based on the synthesized BiOCl micro-assembles was intensively investigated. The results demonstrated that the BiOCl catalyst exhibited promising ORR performance. Koutecky-Levich analysis indicated that a two-electron reaction was favored for the ORR mechanism of the BiOCl (0.18) sample.

  7. 10 CFR 429.43 - Commercial heating, ventilating, air conditioning (HVAC) equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Commercial heating, ventilating, air conditioning (HVAC... Commercial heating, ventilating, air conditioning (HVAC) equipment. (a) Sampling plan for selection of units... each basic model of commercial heating, ventilating, air conditioning (HVAC) equipment, efficiency...

  8. 10 CFR 429.43 - Commercial heating, ventilating, air conditioning (HVAC) equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Commercial heating, ventilating, air conditioning (HVAC... Commercial heating, ventilating, air conditioning (HVAC) equipment. (a) Sampling plan for selection of units... each basic model of commercial heating, ventilating, air conditioning (HVAC) equipment, efficiency...

  9. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Optional equipment and air conditioning for test vehicles. For test vehicles selected under §§ 86.1822-01... be expected to influence emissions include, but are not limited to: air conditioning, power steering...) Except for air conditioning, where it is expected that 33 percent or less of a car line, within a...

  10. 40 CFR 86.165-12 - Air conditioning idle test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Air conditioning idle test procedure... Complete Heavy-Duty Vehicles; Test Procedures § 86.165-12 Air conditioning idle test procedure. (a) Applicability. This section describes procedures for determining air conditioning-related CO2 emissions...

  11. Prediction of Air Conditioning Load Response for Providing Spinning Reserve - ORNL Report

    SciTech Connect

    Kueck, John D; Kirby, Brendan J; Ally, Moonis Raza; Rice, C Keith

    2009-02-01

    This report assesses the use of air conditioning load for providing spinning reserve and discusses the barriers and opportunities. Air conditioning load is well suited for this service because it often increases during heavy load periods and can be curtailed for short periods with little impact to the customer. The report also provides an appendix describing the ambient temperature effect on air conditioning load.

  12. 40 CFR 86.165-12 - Air conditioning idle test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Applicability. This section describes procedures for determining air conditioning-related CO2 emissions from... at idle when CO2 emissions are measured without any air conditioning systems operating, followed by a ten-minute period at idle when CO2 emissions are measured with the air conditioning system...

  13. 40 CFR 86.165-12 - Air conditioning idle test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Applicability. This section describes procedures for determining air conditioning-related CO2 emissions from... at idle when CO2 emissions are measured without any air conditioning systems operating, followed by a ten-minute period at idle when CO2 emissions are measured with the air conditioning system...

  14. 40 CFR 86.166-12 - Method for calculating emissions due to air conditioning leakage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... to air conditioning leakage. 86.166-12 Section 86.166-12 Protection of Environment ENVIRONMENTAL... for calculating emissions due to air conditioning leakage. This section describes procedures used to determine a refrigerant leakage rate in grams per year from vehicle-based air conditioning units....

  15. 40 CFR 86.166-12 - Method for calculating emissions due to air conditioning leakage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... to air conditioning leakage. 86.166-12 Section 86.166-12 Protection of Environment ENVIRONMENTAL... for calculating emissions due to air conditioning leakage. This section describes procedures used to determine a refrigerant leakage rate in grams per year from vehicle-based air conditioning units....

  16. International Space Station Common Cabin Air Assembly Water Separator On-Orbit Operation, Failure, and Redesign

    NASA Technical Reports Server (NTRS)

    Balistreri, Steven F., Jr.; Shaw, Laura A.; Laliberte, Yvon

    2010-01-01

    The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The Water Separator (WS) pulls in air and water from the CHX, and centrifugally separates the mixture, sending the water to the condensate bus and the air back into the CHX outlet airstream. Two distinct early failures of the CCAA Water Separator in the Quest Airlock forced operational changes and brought about the re-design of the Water Separator to improve the useful life via modification kits. The on-orbit operational environment of the Airlock presented challenges that were not foreseen with the original design of the Water Separator. Operational changes were instituted to prolong the life of the third installed WS, while waiting for newly designed Water Separators to be delivered on-orbit. The modification kit design involved several different components of the Water Separator, including the innovative use of a fabrication technique to build the impellers used in Water Separators out of titanium instead of aluminum. The technique allowed for the cost effective production of the low quantity build. This paper will describe the failures of the Water Separators in the Quest Airlock, the operational constraints that were implemented to prolong the life of the installed Water Separators throughout the USOS, and the innovative re-design of the CCAA Water Separator.

  17. Indoor air quality and energy performance of air-conditioned office buildings in Singapore.

    PubMed

    Sekhar, S C; Tham, K W; Cheong, K W

    2003-12-01

    An integrated indoor air quality (IAQ)-energy audit methodology has been developed in this study in Singapore, which provides a rigorous and systematic method of obtaining the status-quo assessment of an 'IAQ signature' in a building. The methodology entails a multi-disciplinary model in obtaining measured data pertaining to different dimensions within the built environment such as the physical, chemical, biological, ventilation, and occupant response characteristics. This paper describes the audit methodology and presents the findings from five air-conditioned office buildings in Singapore. The research has also led to the development of an indoor pollutant standard index (IPSI), which is discussed in this paper. Other performance indicators such as, the ventilation index and the energy index as well as the building symptom index (BSI) are also presented and discussed in the context of an integrated approach to IAQ and energy. Several correlation attempts were made on the various symptoms, indoor air acceptability, thermal comfort, BSI and IPSI, and while BSI values are found to correlate among them as well as with IAQ and THERMAL COMFORT acceptability, no such correlation was observed between BSI and IPSI. This would suggest that the occupants' perception of symptoms experienced as well as environmental acceptability is quite distinct from IAQ acceptability determined from empirical measurements of indoor pollutants, which reinforces the complex nature of IAQ issues.

  18. Understanding the Dehumidification Performance of Air-Conditioning Equipment at Part-Load Conditions

    SciTech Connect

    Don B. Shirey III; Hugh I. Henderson Jr; Richard A. Raustad

    2006-01-01

    Air conditioner cooling coils typically provide both sensible cooling and moisture removal. Data from a limited number of field studies (Khattar et al. 1985; Henderson and Rengarajan 1996; Henderson 1998) have demonstrated that the moisture removal capacity of a cooling coil degrades at part-load conditions--especially when the supply fan operates continuously while the cooling coil cycles on and off. Degradation occurs because moisture that condenses on the coil surfaces during the cooling cycle evaporates back into air stream when the coil is off. This degradation affects the ability of cooling equipment to maintain proper indoor humidity levels and may negatively impact indoor air quality. This report summarizes the results of a comprehensive project to better understand and quantify the moisture removal (dehumidification) performance of cooling coils at part-load conditions. A review of the open literature was initially conducted to learn from previous research on this topic. Detailed performance measurements were then collected for eight cooling coils in a controlled laboratory setting to understand the impact of coil geometry and operating conditions on transient moisture condensation and evaporation by the coils. Measurements of cooling coil dehumidification performance and space humidity levels were also collected at seven field test sites. Finally, an existing engineering model to predict dehumidification performance degradation for single-stage cooling equipment at part-load conditions (Henderson and Rengarajan 1996) was enhanced to include a broader range of fan control strategies and an improved theoretical basis for modeling off-cycle moisture evaporation from cooling coils. The improved model was validated with the laboratory measurements, and this report provides guidance for users regarding proper model inputs. The model is suitable for use in computerized calculation procedures such as hourly or sub-hourly building energy simulation programs (e

  19. Intraoral air pressure and oral air flow under different bleed and bite-block conditions.

    PubMed

    Putnam, A H; Shelton, R L; Kastner, C U

    1986-03-01

    Intraoral pressures and oral flows were measured as normal talkers produced /p lambda/ and /si/ under experimental conditions that perturbed the usual aeromechanical production characteristics of the consonants. A translabial pressure-release device was used to bleed off intraoral pressure during /p/. Bite-blocks were used to open the anterior bite artificially during /s/. For /p/, intraoral pressure decreased and translabial air leakage increased as bleed orifice area increased. For /s/, flow increased as the area of sibilant constriction increased, but differential pressure across the /s/ oral constriction did not vary systematically with changes in its area. Flow on postconsonantal vowels /lambda/ and /i/ did not vary systematically across experimental conditions. The data imply that maintenance of perturbed intraoral pressure was more effective when compensatory options included opportunity for increased respiratory drive and structural adjustments at the place of consonant articulation rather than increased respiratory drive alone.

  20. On the impact of entrapped air in infiltration under ponding conditions: Part a: Preferential air flow path effects on infiltration

    NASA Astrophysics Data System (ADS)

    Weisbord, N.; Mizrahi, G.; Furman, A.

    2015-12-01

    Entrapped air effects on infiltration under ponding conditions could be important for massive infiltration of managed aquifer recharge or soil aquifer treatment. Earlier studies found that under ponding conditions air could reduce infiltration by 70-90%. Most studies have dealt with entrapped air effects when soil surface topography is flat. The objective of this study is to investigate the effects of: (1) irregular surface topography on preferential air flow path development; (2) preferential air flow path on infiltration; and (3) hydraulic head on infiltration when air is trapped. Column experiments were used to investigate these particular effects. A 140 cm deep and 30 cm wide column packed with silica sand was used under two boundary conditions: in the first, air can only escape vertically upward through the soil surface; in the second, air is free to escape. The surface was flooded with 13 liters of water, with ponding depth decreasing with time. Two soil surface conditions were tested: flat surface and irregular. It was found that in irregular surfaces, stable air flow through preferential paths was developed in the high altitude zones. Flat surface topography caused unstable air flow through random paths. Comparison between irregular and flat surface topography showed that the entrapped air pressure was lower and the infiltration rate was about 40% higher in the irregular surface topography than in the flat surface topography. No difference of infiltration rate between flat and irregular surface topography was observed when air was free to escape along the infiltration path. It was also found that at the first stage of infiltration, higher hydraulic heads caused higher entrapped air pressures and lower infiltration rates. In contrast, higher hydraulic head results in higher infiltration rate, when air was free to escape. Our results suggest that during ponding conditions: (1) preferential air flow paths develop at high surface zones of irregular topography

  1. Influence of the inlet air in efficiency of photocatalytic devices for mineralization of VOCs in air-conditioning installations.

    PubMed

    Jimenez-Relinque, E; Castellote, M

    2014-10-01

    Nowadays, a large proportion of photocatalytic oxidation (PCO) devices are being implemented in heating, ventilation and air-conditioning systems. However, no systematic studies have been carried out regarding the influence of inlet air preconditioning. To analyse the impact of the inlet air-conditions into photocatalytic efficiency, a simulated air-conditioning duct with flowing gas through inside was designed. Isobutylene was chosen as the target VOCs. The concentration in the gas phase was monitored using a photoionization detector. The influence of flow rate, relative humidity and temperature on the VOC removal efficiency was analysed. Experimental results were presented in terms of gas-removal efficiency (η) and clean air delivery rate (CADR) and analysed on a kinetic basis. From them, the weight of each parameter in the global process has been determined, from bigger to smaller contribution, flow>temperature>relative humidity. Also, the relevance of the inlet air conditions has been illustrated in a model room in order to determinate the time necessary to obtain a threshold value accomplishing with enough air quality and the energy consumption of the device. Additionally, the photocatalytic decontamination has been assimilated to the "air exchange rate", a parameter commonly used in indoor air quality studies. The results show that preconditioning of air can improve the efficiency of photocatalytic devices and bring important energy savings.

  2. Liquid Desiccant in Air Conditioners: Nano-Engineered Porous Hollow Fiber Membrane-Based Air Conditioning System

    SciTech Connect

    2010-09-02

    BEETIT Project: UTRC is developing an air conditioning system that is optimized for use in warm and humid climates. UTRC’s air conditioning system integrates a liquid drying agent or desiccant and a traditional vapor compression system found in 90% of air conditioners. The drying agent reduces the humidity in the air before it is cooled, using less energy. The technology uses a membrane as a barrier between the air and the liquid salt stream allowing only water vapor to pass through and not the salt molecules. This solves an inherent problem with traditional liquid desiccant systems—carryover of the liquid drying agent into the conditioned air stream—which eliminates corrosion and health issues

  3. Validation of two air quality models for Indian mining conditions.

    PubMed

    Chaulya, S K; Ahmad, M; Singh, R S; Bandopadhyay, L K; Bondyopadhay, C; Mondal, G C

    2003-02-01

    All major mining activity particularly opencast mining contributes to the problem of suspended particulate matter (SPM) directly or indirectly. Therefore, assessment and prediction are required to prevent and minimize the deterioration of SPM due to various opencast mining operations. Determination of emission rate of SPM for these activities and validation of air quality models are the first and foremost concern. In view of the above, the study was taken up for determination of emission rate for SPM to calculate emission rate of various opencast mining activities and validation of commonly used two air quality models for Indian mining conditions. To achieve the objectives, eight coal and three iron ore mining sites were selected to generate site specific emission data by considering type of mining, method of working, geographical location, accessibility and above all resource availability. The study covers various mining activities and locations including drilling, overburden loading and unloading, coal/mineral loading and unloading, coal handling or screening plant, exposed overburden dump, stock yard, workshop, exposed pit surface, transport road and haul road. Validation of the study was carried out through Fugitive Dust Model (FDM) and Point, Area and Line sources model (PAL2) by assigning the measured emission rate for each mining activity, meteorological data and other details of the respective mine as an input to the models. Both the models were run separately for the same set of input data for each mine to get the predicted SPM concentration at three receptor locations for each mine. The receptor locations were selected such a way that at the same places the actual filed measurement were carried out for SPM concentration. Statistical analysis was carried out to assess the performance of the models based on a set measured and predicted SPM concentration data. The value of coefficient of correlation for PAL2 and FDM was calculated to be 0.990-0.994 and 0

  4. Substrateless Welding of Self-Assembled Silver Nanowires at Air/Water Interface.

    PubMed

    Hu, Hang; Wang, Zhongyong; Ye, Qinxian; He, Jiaqing; Nie, Xiao; He, Gufeng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Tao, Peng; Deng, Tao

    2016-08-10

    Integrating connected silver nanowire networks with flexible polymers has appeared as a popular way to prepare flexible electronics. To reduce the contact resistance and enhance the connectivity between silver nanowires, various welding techniques have been developed. Herein, rather than welding on solid supporting substrates, which often requires complicated transferring operations and also may pose damage to heat-sensitive substrates, we report an alternative approach to prepare easily transferrable conductive networks through welding of self-assembled silver nanowires at the air/water interface using plasmonic heating. The intriguing welding behavior of partially aligned silver nanowires was analyzed with combined experimental observation and theoretical modeling. The underlying water not only physically supports the assembled silver nanowires but also buffers potential overheating during the welding process, thereby enabling effective welding within a broad range of illumination power density and illumination duration. The welded networks could be directly integrated with PDMS substrates to prepare high-performance stable flexible heaters that are stretchable, bendable, and can be easily patterned to explore selective heating applications. PMID:27437907

  5. Substrateless Welding of Self-Assembled Silver Nanowires at Air/Water Interface.

    PubMed

    Hu, Hang; Wang, Zhongyong; Ye, Qinxian; He, Jiaqing; Nie, Xiao; He, Gufeng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Tao, Peng; Deng, Tao

    2016-08-10

    Integrating connected silver nanowire networks with flexible polymers has appeared as a popular way to prepare flexible electronics. To reduce the contact resistance and enhance the connectivity between silver nanowires, various welding techniques have been developed. Herein, rather than welding on solid supporting substrates, which often requires complicated transferring operations and also may pose damage to heat-sensitive substrates, we report an alternative approach to prepare easily transferrable conductive networks through welding of self-assembled silver nanowires at the air/water interface using plasmonic heating. The intriguing welding behavior of partially aligned silver nanowires was analyzed with combined experimental observation and theoretical modeling. The underlying water not only physically supports the assembled silver nanowires but also buffers potential overheating during the welding process, thereby enabling effective welding within a broad range of illumination power density and illumination duration. The welded networks could be directly integrated with PDMS substrates to prepare high-performance stable flexible heaters that are stretchable, bendable, and can be easily patterned to explore selective heating applications.

  6. 32 CFR 809a.9 - Conditions for use of Air Force resources.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Conditions for use of Air Force resources. 809a.9 Section 809a.9 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE... Disturbance Intervention and Disaster Assistance § 809a.9 Conditions for use of Air Force resources. This...

  7. 32 CFR 809a.9 - Conditions for use of Air Force resources.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Conditions for use of Air Force resources. 809a.9 Section 809a.9 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE... Disturbance Intervention and Disaster Assistance § 809a.9 Conditions for use of Air Force resources. This...

  8. 32 CFR 809a.9 - Conditions for use of Air Force resources.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Conditions for use of Air Force resources. 809a.9 Section 809a.9 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE... Disturbance Intervention and Disaster Assistance § 809a.9 Conditions for use of Air Force resources. This...

  9. Quality Heterostructures from Two-Dimensional Crystals Unstable in Air by Their Assembly in Inert Atmosphere.

    PubMed

    Cao, Y; Mishchenko, A; Yu, G L; Khestanova, E; Rooney, A P; Prestat, E; Kretinin, A V; Blake, P; Shalom, M B; Woods, C; Chapman, J; Balakrishnan, G; Grigorieva, I V; Novoselov, K S; Piot, B A; Potemski, M; Watanabe, K; Taniguchi, T; Haigh, S J; Geim, A K; Gorbachev, R V

    2015-08-12

    Many layered materials can be cleaved down to individual atomic planes, similar to graphene, but only a small minority of them are stable under ambient conditions. The rest react and decompose in air, which has severely hindered their investigation and potential applications. Here we introduce a remedial approach based on cleavage, transfer, alignment, and encapsulation of air-sensitive crystals, all inside a controlled inert atmosphere. To illustrate the technology, we choose two archetypal two-dimensional crystals that are of intense scientific interest but are unstable in air: black phosphorus and niobium diselenide. Our field-effect devices made from their monolayers are conductive and fully stable under ambient conditions, which is in contrast to the counterparts processed in air. NbSe2 remains superconducting down to the monolayer thickness. Starting with a trilayer, phosphorene devices reach sufficiently high mobilities to exhibit Landau quantization. The approach offers a venue to significantly expand the range of experimentally accessible two-dimensional crystals and their heterostructures.

  10. Assessing summertime urban air conditioning consumption in a semiarid environment

    NASA Astrophysics Data System (ADS)

    Salamanca, F.; Georgescu, M.; Mahalov, A.; Moustaoui, M.; Wang, M.; Svoma, B. M.

    2013-09-01

    Evaluation of built environment energy demand is necessary in light of global projections of urban expansion. Of particular concern are rapidly expanding urban areas in environments where consumption requirements for cooling are excessive. Here, we simulate urban air conditioning (AC) electric consumption for several extreme heat events during summertime over a semiarid metropolitan area with the Weather Research and Forecasting (WRF) model coupled to a multilayer building energy scheme. Observed total load values obtained from an electric utility company were split into two parts, one linked to meteorology (i.e., AC consumption) which was compared to WRF simulations, and another to human behavior. WRF-simulated non-dimensional AC consumption profiles compared favorably to diurnal observations in terms of both amplitude and timing. The hourly ratio of AC to total electricity consumption accounted for ˜53% of diurnally averaged total electric demand, ranging from ˜35% during early morning to ˜65% during evening hours. Our work highlights the importance of modeling AC electricity consumption and its role for the sustainable planning of future urban energy needs. Finally, the methodology presented in this article establishes a new energy consumption-modeling framework that can be applied to any urban environment where the use of AC systems is prevalent.

  11. Ambient air conditions and variation in urban trail use.

    PubMed

    Holmes, Ann M; Lindsey, Greg; Qiu, Chenchen

    2009-11-01

    This study examines the effect of air quality and administrative policies on use of urban trails in Indianapolis, IN. Attention is focused on two policy variables: (1) issuance of air pollution advisories and (2) the adoption of Daylight Savings Time. Results suggest that while trail use varies with air quality, current public advisories regarding air pollution may be of limited effectiveness in reducing trail users' exposures to hazardous pollutants. In contrast, the adoption of Daylight Savings Time was associated with a statistically significant increase in traffic levels.

  12. Capillarity-induced directed self-assembly of patchy hexagram particles at the air-water interface.

    PubMed

    Kang, Sung-Min; Choi, Chang-Hyung; Kim, Jongmin; Yeom, Su-Jin; Lee, Daeyeon; Park, Bum Jun; Lee, Chang-Soo

    2016-07-01

    Directed self-assembly can produce ordered or organized superstructures from pre-existing building blocks through pre-programmed interactions. Encoding desired information into building blocks with specific directionality and strength, however, poses a significant challenge for the development of self-assembled superstructures. Here, we demonstrate that controlling the shape and patchiness of particles trapped at the air-water interface can represent a powerful approach for forming ordered macroscopic complex structures through capillary interactions. We designed hexagram particles using a micromolding method that allowed for precise control over the shape and, more importantly, the chemical patchiness of the particles. The assembly behaviors of these hexagram particles at the air-water interface were strongly affected by chemical patchiness. In particular, two-dimensional millimeter-scale ordered structures could be formed by varying the patchiness of the hexagram particles, and we attribute this effect to the delicate balance between the attractive and repulsive interactions among the patchy hexagram particles. Our results provide important clues for encoding information into patchy particles to achieve macroscopic assemblies via a simple molding technique and potentially pave a new pathway for the programmable assembly of particles at the air-water interface.

  13. Capillarity-induced directed self-assembly of patchy hexagram particles at the air-water interface.

    PubMed

    Kang, Sung-Min; Choi, Chang-Hyung; Kim, Jongmin; Yeom, Su-Jin; Lee, Daeyeon; Park, Bum Jun; Lee, Chang-Soo

    2016-07-01

    Directed self-assembly can produce ordered or organized superstructures from pre-existing building blocks through pre-programmed interactions. Encoding desired information into building blocks with specific directionality and strength, however, poses a significant challenge for the development of self-assembled superstructures. Here, we demonstrate that controlling the shape and patchiness of particles trapped at the air-water interface can represent a powerful approach for forming ordered macroscopic complex structures through capillary interactions. We designed hexagram particles using a micromolding method that allowed for precise control over the shape and, more importantly, the chemical patchiness of the particles. The assembly behaviors of these hexagram particles at the air-water interface were strongly affected by chemical patchiness. In particular, two-dimensional millimeter-scale ordered structures could be formed by varying the patchiness of the hexagram particles, and we attribute this effect to the delicate balance between the attractive and repulsive interactions among the patchy hexagram particles. Our results provide important clues for encoding information into patchy particles to achieve macroscopic assemblies via a simple molding technique and potentially pave a new pathway for the programmable assembly of particles at the air-water interface. PMID:27328067

  14. Allergies to molds caused by fungal spores in air conditioning equipment

    SciTech Connect

    Schata, M.; Jorde, W. ); Elixmann, J.H.; Linskens, H.F. )

    1989-01-01

    People suffering from various symptoms while in air-conditioned rooms often show sensitizations to fungi that can be isolated when the fungi are removed from air conditioners. By using specific challenge tests it was shown that fungal spores in air conditioners can evoke allergic symptoms. Hyposensitization was the specific therapy prescribed for such allergic reactions. After hyposensitization therapy, more than 70% of the patients so treated could live and work again in air-conditioned rooms without developing specific symptoms.

  15. Apparatus for supplying conditioned air at a substantially constant temperature and humidity

    NASA Technical Reports Server (NTRS)

    Obler, H. D. (Inventor)

    1980-01-01

    The apparatus includes a supply duct coupled to a source of supply air for carrying the supply air therethrough. A return duct is coupled to the supply duct for carrying return conditioned air therethrough. A temperature reducing device is coupled to the supply duct for decreasing the temperature of the supply and return conditioned air. A by-pass duct is coupled to the supply duct for selectively directing portions of the supply and return conditioned air around the temperature reducing device. Another by-pass duct is coupled to the return duct for selectively directing portions of the return conditioned air around the supply duct and the temperature reduction device. Controller devices selectively control the flow and amount of mixing of the supply and return conditioned air.

  16. Poaceae pollen in the air depending on the thermal conditions.

    PubMed

    Myszkowska, Dorota

    2014-07-01

    The relationship between the meteorological elements, especially the thermal conditions and the Poaceae pollen appearance in the air, were analysed as a basis to construct a useful model predicting the grass season start. Poaceae pollen concentrations were monitored in 1991-2012 in Kraków using the volumetric method. Cumulative temperature and effective cumulative temperature significantly influenced the season start in this period. The strongest correlation was seen as the sum of mean daily temperature amplitudes from April 1 to April 14, with mean daily temperature>15 °C and effective cumulative temperature>3 °C during that period. The proposed model, based on multiple regression, explained 57% of variation of the Poaceae season starts in 1991-2010. When cumulative mean daily temperature increased by 10 °C, the season start was accelerated by 1 day. The input of the interaction between these two independent variables into the factor regression model caused the increase in goodness of model fitting. In 2011 the season started 5 days earlier in comparison with the predicted value, while in 2012 the season start was observed 2 days later compared to the predicted day. Depending on the value of mean daily temperature from March 18th to the 31st and the sum of mean daily temperature amplitudes from April 1st to the 14th, the grass pollen seasons were divided into five groups referring to the time of season start occurrence, whereby the early and moderate season starts were the most frequent in the studied period and they were especially related to mean daily temperature in the second half of March.

  17. Commentary: Air-conditioning as a risk for increased use of healthservices

    SciTech Connect

    Mendell, Mark J.

    2004-06-01

    In this issue of the journal, Preziosi et al. [2004] report the first study to assess differences in the utilization of health care related to the presence of air-conditioning in office workplaces. Although the study was simple and cross-sectional, the data variables from questionnaires, and the findings subject to a variety of questions, the findings are striking enough to deserve clarification. The study used a large random national sample of French women assembled for another purpose (to study antioxidant nutrients and prevention of cancer and cardiovascular disease). Participants reported health services and health events in monthly questionnaires over 1 year, and in one questionnaire in the middle of that period also reported whether air-conditioning was in use at their workplace. Fifteen percent of participants reported air-conditioning at work. Analyses adjusting for age and smoking status of participants found increases in most outcomes assessed: use of specific kinds of physicians, sickness absence, and hospital stays. While the increases in odds ratios (OR) and 95% confidence intervals (CI) were statistically significant for only otorhinolaryngology [OR (95% CI) = 2.33 (1.35-4.04)] and sickness absence [1.70 (1.13-2.58)], other increases were notable--dermatology [1.6 (0.98-2.65)]; hospital stay [1.51 (0.92-2.45)], and pneumonology [2.10 (0.65-6.82)]. The least elevated outcomes were for general practice medicine [0.99 (0.65-1.48)] and global medical visits [1.18 (0.67-2.07)]. [Preziosi et al., 2004 ,(Table 2)] Odds ratios for relatively common health outcomes often lie farther from the null than the risk ratios most useful for quantifying the increase in risk. Risk ratios, or prevalence ratios (PRs, the equivalent measure of effect for cross-sectional data), have seldom been used because of the convenience and availability of logistic regression models that estimate odds ratios. With baseline prevalences ranging up to 85.7% in the data from Preziosi et

  18. [Design, equipment, and management for air conditioning in operating room].

    PubMed

    Fuji, Kumiko; Mizuno, Ju

    2011-11-01

    In order to maintain air cleanliness in the operating room (OR) permanently, air exchange rate in the OR should be more than 15 times x hr(-1), the laminar air flow should be kept, and the numbers of the persons in the OR and the numbers of opening and closing OR door should be limited. High efficiency particulate air (HEPA) filter is effective in collection and removal of airborne microbes, and is used in the biological clean room. We need to design, equip, and manage the OR environment according to Guideline for Design and Operation of Hospital HVAC Systems HEAS-02-2004 established by Healthcare Engineering Association of Japan and Guideline for Prevention of Surgical Site Infection (SSI) established by the Center for Disease Control and Prevention (CDC) in the USA. PMID:22175178

  19. COMPOSITION CHANGES IN REFRIGERANT BLENDS FOR AUTOMOTIVE AIR CONDITIONING

    EPA Science Inventory

    Three refrigerant blends used to replace CFC-12 in automotive air conditioners were evaluated for composition changes due to typical servicing and leakage. When recommended service procedures were followed, changes in blend compositions were relatively small. Small changes in b...

  20. Capability of air filters to retain airborne bacteria and molds in heating, ventilating and air-conditioning (HVAC) systems.

    PubMed

    Möritz, M; Peters, H; Nipko, B; Rüden, H

    2001-07-01

    The capability of air filters (filterclass: F6, F7) to retain airborne outdoor microorganisms was examined in field experiments in two heating, ventilating and air conditioning (HVAC) systems. At the beginning of the 15-month investigation period, the first filter stages of both HVAC systems were equipped with new unused air filters. The number of airborne bacteria and molds before and behind the filters were determined simultaneously in 14 days-intervals using 6-stage Andersen cascade impactors. Under relatively dry (< 80% R. H.) and warm (> 12 degrees C) outdoor air conditions air filters led to a marked reduction of airborne microorganism concentrations (bacteria by approximately 70% and molds by > 80%). However, during long periods of high relative humidity (> 80% R. H.) a proliferation of bacteria on air filters with subsequent release into the filtered air occurred. These microorganisms were mainly smaller than 1.1 microns therefore being part of the respirable fraction. The results showed furthermore that one possibility to avoid microbial proliferation is to limit the relative humidity in the area of the air filters to 80% R. H. (mean of 3 days), e.g. by using preheaters in front of air filters in HVAC-systems.

  1. Impact of air conditioning system operation on increasing gases emissions from automobile

    NASA Astrophysics Data System (ADS)

    Burciu, S. M.; Coman, G.

    2016-08-01

    The paper presents a study concerning the influence of air conditioning system operation on the increase of gases emissions from cars. The study focuses on urban operating regimes of the automobile, regimes when the engines have low loads or are operating at idling. Are presented graphically the variations of pollution emissions (CO, CO2, HC) depending of engine speed and the load on air conditioning system. Additionally are presented, injection duration, throttle position, the mechanical power required by the compressor of air conditioning system and the refrigerant pressure variation on the discharge path, according to the stage of charging of the air conditioning system.

  2. Francisella guangzhouensis sp. nov., isolated from air-conditioning systems.

    PubMed

    Qu, Ping-Hua; Chen, Shou-Yi; Scholz, Holger C; Busse, Hans-Jürgen; Gu, Quan; Kämpfer, Peter; Foster, Jeffrey T; Glaeser, Stefanie P; Chen, Cha; Yang, Zhi-Chong

    2013-10-01

    Four strains (08HL01032(T), 09HG994, 10HP82-6 and 10HL1960) were isolated from water of air-conditioning systems of various cooling towers in Guangzhou city, China. Cells were Gram-stain-negative coccobacilli without flagella, catalase-positive and oxidase-negative, showing no reduction of nitrate, no hydrolysis of urea and no production of H2S. Growth was characteristically enhanced in the presence of l-cysteine, which was consistent with the properties of members of the genus Francisella. The quinone system was composed of ubiquinone Q-8 with minor amounts of Q-9. The polar lipid profile consisted of the predominant lipids phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, two unidentified phospholipids (PL2, PL3), an unidentified aminophospholipid and an unidentified glycolipid (GL2). The polyamine pattern consisted of the major compounds spermidine, cadaverine and spermine. The major cellular fatty acids were C10 : 0, C14 : 0, C16 : 0, C18 : 1ω9c and C18 : 1 3-OH. A draft whole-genome sequence of the proposed type strain 08HL01032(T) was generated. Comparative sequence analysis of the complete 16S and 23S rRNA genes confirmed affiliation to the genus Francisella, with 95 % sequence identity to the closest relatives in the database, the type strains of Francisella philomiragia and Francisella noatunensis subsp. orientalis. Full-length deduced amino acid sequences of various housekeeping genes, recA, gyrB, groEL, dnaK, rpoA, rpoB, rpoD, rpoH, fopA and sdhA, exhibited similarities of 67-92 % to strains of other species of the genus Francisella. Strains 08HL01032(T), 09HG994, 10HP82-6 and 10HL1960 exhibited highly similar pan-genome PCR profiles. Both the phenotypic and molecular data support the conclusion that the four strains belong to the genus Francisella but exhibit considerable divergence from all recognized Francisella species. Therefore, we propose the name Francisella guangzhouensis sp

  3. Formation of a fluorous/organic biphasic supramolecular octopus assembly for enhanced porphyrin phosphorescence in air.

    PubMed

    Yang, Chi; Arvapally, Ravi K; Tekarli, Sammer M; Salazar, Gustavo A; Elbjeirami, Oussama; Wang, Xiaoping; Omary, Mohammad A

    2015-04-13

    The trinuclear triangle-shaped system [tris{3,5-bis(heptafluoropropyl)-1,2,4-triazolatosilver(I)}] (1) and the multi-armed square-shaped metalloporphyrin PtOEP or the free porphyrin base H2OEP serve as excellent octopus hosts (OEP=2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine). Coupling of the fluorous/organic molecular octopi 1 and H2OEP or PtOEP by strong quadrupole-quadrupole and metal-π interactions affords the supramolecular assemblies [1⋅PtOEP] or [1⋅H2OEP] (2 a), which feature nanoscopic cavities surrounding the upper triangular and lower square cores. The fluorous/organic biphasic configuration of [1⋅PtOEP] leads to an increase in the phosphorescence of PtOEP under ambient conditions. Guest molecules can be included in the biphasic double-octopus assembly in three different site-selective modes.

  4. 32 CFR 855.7 - Conditions for use of Air Force airfields.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Conditions for use of Air Force airfields. 855.7 Section 855.7 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits §...

  5. 32 CFR 855.7 - Conditions for use of Air Force airfields.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Conditions for use of Air Force airfields. 855.7 Section 855.7 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits §...

  6. 32 CFR 855.7 - Conditions for use of Air Force airfields.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Conditions for use of Air Force airfields. 855.7 Section 855.7 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits §...

  7. 32 CFR 855.7 - Conditions for use of Air Force airfields.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Conditions for use of Air Force airfields. 855.7 Section 855.7 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits §...

  8. 32 CFR 855.7 - Conditions for use of Air Force airfields.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Conditions for use of Air Force airfields. 855.7 Section 855.7 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits §...

  9. Ice storage rooftop retrofit for rooftop air conditioning

    SciTech Connect

    Tomlinson, J.J.; Jennings, L.W.

    1997-09-01

    A significant fraction of the floor space in commercial and federal buildings is cooled by single-package rooftop air conditioning units. These units are located on flat roofs and usually operate during the day under hot conditions. They are usually less energy efficient than a chiller system for building cooling. Several U.S. companies are developing systems that employ ice storage in conjunction with chillers to replace older, inefficient rooftop units for improved performance and minimal use of on-peak electricity. Although the low evaporator temperatures needed for ice making tend to reduce the efficiency of the chiller, the overall operating costs of the ice storage system may be lower than that of a packaged, conventional rooftop installation. One version of this concept, the Roofberg{reg_sign} System developed by the Calmac Corporation, was evaluated on a small building at Oak Ridge National Laboratory in Oak Ridge, Tennessee. The Roofberg system consists of a chiller, an ice storage tank, and one or more rooftop units whose evaporator coils have been adapted to use a glycol solution for cooling. The ice storage component decouples the cooling demand of the building from the operation of the chiller. Therefore, the chiller can operate at night (cooler, more efficient condensing temperatures) to meet a daytime cooling demand. This flexibility permits a smaller chiller to satisfy a larger peak cooling load. Further, the system can be operated to shift the cooling demand to off-peak hours when electricity from the utility is generated more efficiently and at lower cost. This Roofberg system was successfully installed last year on a small one-story office building in Oak Ridge and is currently being operated to cool the building. The building and system were sufficiently instrumented to allow a determination of the performance and efficiency of the Roofberg system. Although the energy efficiency of a simulated Roofberg storage/chiller concept operating in the

  10. Apparatus and Method for Measuring Air Temperature Ahead of an Aircraft for Controlling a Variable Inlet/Engine Assembly

    NASA Technical Reports Server (NTRS)

    Gary, Bruce L. (Inventor)

    2001-01-01

    The apparatus and method employ remote sensing to measure the air temperature a sufficient distance ahead of the aircraft to allow time for a variable inlet/engine assembly to be reconfigured in response to the measured temperature, to avoid inlet unstart and/or engine compressor stall. In one embodiment, the apparatus of the invention has a remote sensor for measuring at least one air temperature ahead of the vehicle and an inlet control system for varying the inlet. The remote sensor determines a change in temperature value using at least one temperature measurement and prior temperature measurements corresponding to the location of the aircraft. The control system uses the change in air temperature value to vary the inlet configuration to maintain the position of the shock wave during the arrival of the measured air in the inlet. In one embodiment, the method of the invention includes measuring at least one air temperature ahead of the vehicle, determining an air temperature at the vehicle from prior air temperature measurements, determining a change in temperature value using the air temperature at the vehicle and the at least one air temperature measurement ahead of the vehicle, and using the change in temperature value to-reposition the airflow inlet, to cause the shock wave to maintain substantially the same position within the inlet as the airflow temperature changes within the inlet.

  11. Performance of a photovoltaically powered air-conditioning system

    SciTech Connect

    Kern, Jr, E. C.; Millner, A. R.

    1980-01-01

    A vapor-compression air conditioner coupled directly to a photovoltaic array is discussed. Previous analyses of such a system are reviewed, and a development system designed to test the concept is described. Preliminary experiments indicate that the performance of this initial system falls considerably short of analytic expectations.

  12. Retrofitting Air Conditioning and Duct Systems in Hot, Dry Climates

    SciTech Connect

    Shapiro, C.; Aldrich, R.; Arena, L.

    2012-07-01

    This technical report describes CARB's work with Clark County Community Resources Division in Las Vegas, Nevada, to optimize procedures for upgrading cooling systems on existing homes in the area to implement health, safety, and energy improvements. Detailed monitoring of five AC systems showed that three of the five systems met or exceeded air flow rate goals.

  13. Improving microbial air quality in air-conditioned mass transport buses by opening the bus exhaust ventilation fans.

    PubMed

    Luksamijarulkul, Pipat; Arunchai, Nongphon; Luksamijarulkul, Soavalug; Kaewboonchoo, Orawan

    2005-07-01

    The air quality in air-conditioned mass transport buses may affect bus drivers' health. In-bus air quality improvement with the voluntary participation of bus drivers by opening the exhaust ventilation fans in the bus was implemented in the Seventh Bus Zone of Bangkok Mass Transit Authority. Four bus numbers, including bus numbers 16, 63, 67 and 166, were randomly selected to investigate microbial air quality and to observe the effect of opening the exhaust ventilation fans in the bus. With each bus number, 9 to 10 air-conditioned buses (total, 39 air-conditioned buses) were included. In-bus air samples were collected at 5 points in each studied bus using the Millipore Air Tester. A total of 195 air samples were cultured for bacterial and fungal counts. The results reveal that the exhaust ventilation fans of 17 air-conditioned buses (43.6%) were opened to ventilate in-bus air during the cycle of the bus route. The means +/- SD of bacterial counts and fungal counts in the studied buses with opened exhaust ventilation fans (83.8 +/- 70.7 and 38.0 +/- 42.8 cfu/m3) were significantly lower than those in the studied buses without opened exhaust ventilation fans (199.6 +/- 138.8 and 294.1 +/- 178.7 cfu/m3), p < 0.0005. All the air samples collected from the studied buses with opened exhaust ventilation fans were at acceptable levels (< 500 cfu/m3) compared with 4.6% of the air samples collected from the studied buses without opened exhaust ventilation fans, which had high levels (> 500 cfu/m3). Of the studied buses with opened exhaust ventilation fans (17 buses), the bacterial and fungal counts after opening the exhaust ventilation fans (68.3 +/- 33.8 and 28.3 +/- 19.3 cfu/m3) were significantly lower than those before opening the exhaust ventilation fans (158.3 +/- 116.9 and 85.3 +/- 71.2 cfu/m3), p < 0.005.

  14. 10 CFR 429.43 - Commercial heating, ventilating, air conditioning (HVAC) equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Commercial heating, ventilating, air conditioning (HVAC... Commercial heating, ventilating, air conditioning (HVAC) equipment. Link to an amendment published at 78 FR... § 429.11 are applicable to commercial HVAC equipment; and (2) For each basic model of commercial...

  15. The Effect of Air-Conditioning on Student and Teacher Performance.

    ERIC Educational Resources Information Center

    Phoenix Union High School District, AZ. Dept. of Research and Planning.

    The literature is reviewed to see if research shows a relationship between student and teacher performance and air conditioning of classrooms. The benefits of air conditioning in promoting learning are substantiated by studies that are summarized but not cited. The relationship of the report to the Phoenix Union High School System Advisory…

  16. Automotive Air Conditioning and Heating; Automotive Mechanics (Advanced): 9047.04.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to provide the student with all the foundations necessary to become employable in the automotive air conditioning and heating trade. The course of study includes an orientation to the world of work, the elementary physics of air conditioning and heating, and laboratory experiments…

  17. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... initiative, the Administrator will approve a simulation of the environmental cell for air conditioning test... environmental cell test data for the range of vehicles to be covered by the simulation including items such as the tailpipe emissions, air conditioning compressor load, and fuel economy. (2) For any...

  18. 40 CFR 86.166-12 - Method for calculating emissions due to air conditioning leakage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... determine a refrigerant leakage rate in grams per year from vehicle-based air conditioning units. The... using the following equation: Grams/YRTOT = Grams/YRRP + Grams/YRSP + Grams/YRFH + Grams/YRMC + Grams/YRC Where: Grams/YRTOT = Total air conditioning system emission rate in grams per year and rounded...

  19. Criterion-Referenced Test (CRT) Items for Air Conditioning, Heating and Refrigeration.

    ERIC Educational Resources Information Center

    Davis, Diane, Ed.

    These criterion-referenced test (CRT) items for air conditioning, heating, and refrigeration are keyed to the Missouri Air Conditioning, Heating, and Refrigeration Competency Profile. The items are designed to work with both the Vocational Instructional Management System and Vocational Administrative Management System. For word processing and…

  20. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... initiative, the Administrator will approve a simulation of the environmental cell for air conditioning test... environmental cell test data for the range of vehicles to be covered by the simulation including items such as the tailpipe emissions, air conditioning compressor load, and fuel economy. (2) For any...

  1. Reducing indoor air pollution by air conditioning is associated with improvements in cardiovascular health among the general population.

    PubMed

    Lin, Lian-Yu; Chuang, Hsiao-Chi; Liu, I-Jung; Chen, Hua-Wei; Chuang, Kai-Jen

    2013-10-01

    Indoor air pollution is associated with cardiovascular effects, however, little is known about the effects of improving indoor air quality on cardiovascular health. The aim of this study was to explore whether improving indoor air quality through air conditioning can improve cardiovascular health in human subjects. We recruited a panel of 300 healthy subjects from Taipei, aged 20 and over, to participate in six home visits each, to measure a variety of cardiovascular endpoints, including high sensitivity-C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG), fibrinogen in plasma and heart rate variability (HRV). Indoor particles and total volatile organic compounds (VOCs) were measured simultaneously at the participant's home during each visit. Three exposure conditions were investigated in this study: participants were requested to keep their windows open during the first two visits, close their windows during the next two visits, and close the windows and turn on their air conditioners during the last two visits. We used linear mixed-effects models to associate the cardiovascular endpoints with individual indoor air pollutants. The results showed that increases in hs-CRP, 8-OHdG and fibrinogen, and decreases in HRV indices were associated with increased levels of indoor particles and total VOCs in single-pollutant and two-pollutant models. The effects of indoor particles and total VOCs on cardiovascular endpoints were greatest during visits with the windows open. During visits with the air conditioners turned on, no significant changes in cardiovascular endpoints were observed. In conclusion, indoor air pollution is associated with inflammation, oxidative stress, blood coagulation and autonomic dysfunction. Reductions in indoor air pollution and subsequent improvements in cardiovascular health can be achieved by closing windows and turning on air conditioners at home.

  2. Opportunities to Reduce Air-Conditioning Loads Through Lower Cabin Soak Temperatures

    SciTech Connect

    Farrington, R.; Cuddy, M.; Keyser, M.; Rugh, J.

    1999-07-12

    Air-conditioning loads can significantly reduce electric vehicle (EV) range and hybrid electric vehicle (HEV) fuel economy. In addition, a new U. S. emissions procedure, called the Supplemental Federal Test Procedure (SFTP), has provided the motivation for reducing the size of vehicle air-conditioning systems in the United States. The SFTP will measure tailpipe emissions with the air-conditioning system operating. If the size of the air-conditioning system is reduced, the cabin soak temperature must also be reduced, with no penalty in terms of passenger thermal comfort. This paper presents the impact of air-conditioning on EV range and HEV fuel economy, and compares the effectiveness of advanced glazing and cabin ventilation. Experimental and modeled results are presented.

  3. Reduction of air ion mobility to standard conditions

    NASA Astrophysics Data System (ADS)

    Tammet, H.

    1998-06-01

    The Langevin rule of the reduction of air ion mobility is adequate in case of zero-size ions. An alternative is the Stokes-Millikan equation that is adequate in the limit of macroscopic charged particles. The temperature variation of air ion mobility predicted by the Stokes-Millikan equation radically contradicts the Langevin rule. The temperature and pressure variation of air ion mobility is examined by using a new semiempirical model that describes the transition from the kinetic theory to the Stokes-Millikan equation. The model is valid in full mobility range. It allows to calculate at first the size of an ion according to the measured mobility and then the standard mobility according to the size. The ascent of the temperature-mobility curve on a logarithmic chart approaches the Langevin value of 1 only at very high mobilities not found in the atmosphere. The value of the ascent is 0.6 in the case of small ions of the mobility of 1.5 cm2 V-1 s-1 which brings about a considerable error when using the Langevin rule. It is recommended to store the natural values of the mobility in databases together with the values of temperature and pressure and to definitely indicate the method when the reduced mobilities are presented in publications.

  4. Capillary-driven self-assembly of microchips on oleophilic/oleophobic patterned surface using adhesive droplet in ambient air

    NASA Astrophysics Data System (ADS)

    Chang, Bo; Sariola, Veikko; Aura, Susanna; Ras, Robin H. A.; Klonner, Maria; Lipsanen, Harri; Zhou, Quan

    2011-07-01

    This letter describes a capillary-driven self-assembly technique using oleophilic/oleophobic patterned surface and adhesive in ambient air environment. We use a topographical microstructure of porous ormocer functionalized with a fluorinated trichlorosilane for the oleophobic area and gold patterns for the oleophilic area. The resulted oleophilic/oleophobic patterns show significant wettability contrast for adhesive (Delo 18507), with a contact angle of 119° on oleophobic part and 53° on the oleophilic part. Self-alignment of SU-8 microchips on the oleophilic/oleophobic patterns has been demonstrated. The results provide a promising solution for self-alignment of microparts using commercial adhesives in ambient air environment.

  5. Low-Flow Liquid Desiccant Air Conditioning: General Guidance and Site Considerations

    SciTech Connect

    Kozubal, E.; Herrmann, L.; Deru, M.; Clark, J.

    2014-09-01

    Dehumidification or latent cooling in buildings is an area of growing interest that has been identified as needing more research and improved technologies for higher performance. Heating, ventilating, and air-conditioning (HVAC) systems typically expend excessive energy by using overcool-and-reheat strategies to dehumidify buildings. These systems first overcool ventilation air to remove moisture and then reheat the air to meet comfort requirements. Another common strategy incorporates solid desiccant rotors that remove moisture from the air more efficiently; however, these systems increase fan energy consumption because of the high airside pressure drop of solid desiccant rotors and can add heat of absorption to the ventilation air. Alternatively, liquid desiccant air-conditioning (LDAC) technology provides an innovative dehumidification solution that: (1) eliminates the need for overcooling and reheating from traditional cooling systems; and (2) avoids the increased fan energy and air heating from solid desiccant rotor systems.

  6. Non-equilibrium magnetic colloidal dispersions at liquid-air interfaces: dynamic patterns, magnetic order and self-assembled swimmers.

    PubMed

    Snezhko, Alexey

    2011-04-20

    Colloidal dispersions of interacting particles subjected to an external periodic forcing often develop nontrivial self-assembled patterns and complex collective behavior. A fundamental issue is how collective ordering in such non-equilibrium systems arises from the dynamics of discrete interacting components. In addition, from a practical viewpoint, by working in regimes far from equilibrium new self-organized structures which are generally not available through equilibrium thermodynamics can be created. In this review spontaneous self-assembly phenomena in magnetic colloidal dispersions suspended at liquid-air interfaces and driven out of equilibrium by an alternating magnetic field are presented. Experiments reveal a new type of nontrivially ordered self-assembled structures emerging in such systems in a certain range of excitation parameters. These dynamic structures emerge as a result of the competition between magnetic and hydrodynamic forces and have complex unconventional magnetic ordering. Nontrivial self-induced hydrodynamic fields accompany each out-of-equilibrium pattern. Spontaneous symmetry breaking of the self-induced surface flows leading to a formation of self-propelled microstructures has been discovered. Some features of the self-localized structures can be understood in the framework of the amplitude equation (Ginzburg-Landau type equation) for parametric waves coupled to the conservation law equation describing the evolution of the magnetic particle density and the Navier-Stokes equation for hydrodynamic flows. To understand the fundamental microscopic mechanisms governing self-assembly processes in magnetic colloidal dispersions at liquid-air interfaces a first-principle model for a non-equilibrium self-assembly is presented. The latter model allows us to capture in detail the entire process of out-of-equilibrium self-assembly in the system and reproduces most of the observed phenomenology.

  7. Combustion of Gaseous Fuels with High Temperature Air in Normal- and Micro-gravity Conditions

    NASA Technical Reports Server (NTRS)

    Wang, Y.; Gupta, A. K.

    2001-01-01

    The objective of this study is determine the effect of air preheat temperature on flame characteristics in normal and microgravity conditions. We have obtained qualitative (global flame features) and some quantitative information on the features of flames using high temperature combustion air under normal gravity conditions with propane and methane as the fuels. This data will be compared with the data under microgravity conditions. The specific focus under normal gravity conditions has been on determining the global flame features as well as the spatial distribution of OH, CH, and C2 from flames using high temperature combustion air at different equivalence ratio.

  8. [Working ability between air and trimix breathing gas under 8 ATA air condition].

    PubMed

    Shibayama, M; Kosugi, S; Mohri, M; Yamamura, I; Oda, S; Kimura, A; Takeuchi, J; Mano, Y

    1990-04-01

    Pneumatic caisson work in Japan has come into operation since 1924. Afterward, this technique of compressed air work has been widely utilized in the construction of foundation basements, shafts of the bottom tunnel shields for subway and so forth. While using this technique of compressed air work means that workers have to be exposed to hyperbaric environment, this technique has risks of not only decompression sickness (DCS) but also toxicity of poisonous gas and/or oxygen deficiency. However, this technique is independent of city construction work and the operation of compressed air work higher than 5ATA (4.0 kg/cm2G) is actually been planning recently. Accordingly unmanned caisson work is considered as a better technique for such higher pressurized work, even though workers must enter into hyperbaric working fields for maintenance or repair of unmanned operated machinery and materials. This research is to establish the safe work under hyperbaric air environment at 8ATA. PMID:2400467

  9. The Design of Research Laboratories. Part I: A General Assessment. Part II: Air Conditioning and Conditioned Rooms.

    ERIC Educational Resources Information Center

    Legget, R. F.; Hutcheon, N. B.

    Design factors in the planning of research laboratories are described which include--(1) location, (2) future expansion, (3) internal flexibility, (4) provision of services, (5) laboratory furnishing, (6) internal traffic, (7) space requirements, and (8) building costs. A second part discusses air-conditioning and conditioned rooms--(1)…

  10. A Theoretical Investigation of Oxidation Efficiency of a Volatile Removal Assembly Reactor Under Microgravity Conditions

    NASA Technical Reports Server (NTRS)

    Guo, Boyun

    2005-01-01

    Volatile Removal Assembly (VRA) is a subsystem of the Closed Environment Life Support System (CELSS) installed in the International Space Station. It is used for removing contaminants (volatile organics) in the wastewater produced by the space station crews. The major contaminants are formic acid, ethanol, and propylene glycol. The VRA contains a slim packbed reactor (3.5 cm diameter and four 28 cm long tubes in series) to perform catalyst oxidation of wastewater at elevated pressure and temperature under microgravity conditions. In the reactor, the contaminants are burned with oxygen gas (O2) to form water and carbon dioxide (CO2) that dissolves in the water stream. Optimal design of the reactor requires a thorough understanding about how the reactor performs under microgravity conditions. The objective of this study was to develop a mathematical model to interpret experimental data obtained from normal and microgravity conditions, and to predict the performance of VRA reactor under microgravity conditions. Catalyst oxidation kinetics and the total oxygen-water contact area control the efficiency of catalyst oxidation for mass transfer, which depends on oxygen gas holdup and distribution in the reactor. The process involves bubbly flow in porous media with chemical reactions in microgravity environment. This presents a unique problem in fluid dynamics that has not been studied. Guo et al. (2004) developed a mathematical model that predicts oxygen holdup in the VRA reactor. No mathematical model has been found in the literature that can be used to predict the efficiency of catalyst oxidation under microgravity conditions.

  11. [Influence of industrial pollution of ambient air on health of workers engaged into open air activities in cold conditions].

    PubMed

    Chashchin, V P; Siurin, S A; Gudkov, A B; Popova, O N; Voronin, A Iu

    2014-01-01

    The article presents the results of a study on assessment of occupational exposure to air pollutants and related health effects in3792 outdoor workers engaged in operations performed in the vicinity of non-ferrous metallurgical facilities in Far North. Findings are that during cold season repeated climate and weather conditions are associated with higher level of chemical hazards and dust in surface air. At the air temperature below -17 degrees C, maximal single concentrations of major pollutants can exceed MAC up to 10 times. With that, transitory disablement morbidity parameters and occupational accidents frequency increase significantly. The workers with long exposure to cooling meteorological factors and air pollution demonstrate significantly increased prevalence of respiratory and circulatory diseases, despite relatively low levels of sculpture dioxide and dust in the air, not exceeding the occupational exposure limits. It has been concluded that severe cold is to be considered asa factor increasing occupational risk at air polluted outdoor worksites dueto more intense air pollution, higher traumatism risk and lower efficiency of filter antidust masks respiratory PPE and due to modification of the toxic effects.

  12. Impaired Air Conditioning within the Nasal Cavity in Flat-Faced Homo.

    PubMed

    Nishimura, Takeshi; Mori, Futoshi; Hanida, Sho; Kumahata, Kiyoshi; Ishikawa, Shigeru; Samarat, Kaouthar; Miyabe-Nishiwaki, Takako; Hayashi, Misato; Tomonaga, Masaki; Suzuki, Juri; Matsuzawa, Tetsuro; Matsuzawa, Teruo

    2016-03-01

    We are flat-faced hominins with an external nose that protrudes from the face. This feature was derived in the genus Homo, along with facial flattening and reorientation to form a high nasal cavity. The nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. In this study, we used computational fluid dynamics (CFD) with three-dimensional topology models of the nasal passage under the same simulation conditions, to investigate air-conditioning performance in humans, chimpanzees, and macaques. The CFD simulation showed a horizontal straight flow of inhaled air in chimpanzees and macaques, contrasting with the upward and curved flow in humans. The inhaled air is conditioned poorly in humans compared with nonhuman primates. Virtual modifications to the human external nose topology, in which the nasal vestibule and valve are modified to resemble those of chimpanzees, change the airflow to be horizontal, but have little influence on the air-conditioning performance in humans. These findings suggest that morphological variation of the nasal passage topology was only weakly sensitive to the ambient atmosphere conditions; rather, the high nasal cavity in humans was formed simply by evolutionary facial reorganization in the divergence of Homo from the other hominin lineages, impairing the air-conditioning performance. Even though the inhaled air is not adjusted well within the nasal cavity in humans, it can be fully conditioned subsequently in the pharyngeal cavity, which is lengthened in the flat-faced Homo. Thus, the air-conditioning faculty in the nasal passages was probably impaired in early Homo members, although they have survived successfully under the fluctuating climate of the Plio-Pleistocene, and then they moved "Out of Africa" to explore the more severe climates of

  13. Impaired Air Conditioning within the Nasal Cavity in Flat-Faced Homo

    PubMed Central

    Nishimura, Takeshi; Mori, Futoshi; Hanida, Sho; Kumahata, Kiyoshi; Ishikawa, Shigeru; Samarat, Kaouthar; Miyabe-Nishiwaki, Takako; Hayashi, Misato; Tomonaga, Masaki; Suzuki, Juri; Matsuzawa, Tetsuro; Matsuzawa, Teruo

    2016-01-01

    We are flat-faced hominins with an external nose that protrudes from the face. This feature was derived in the genus Homo, along with facial flattening and reorientation to form a high nasal cavity. The nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. In this study, we used computational fluid dynamics (CFD) with three-dimensional topology models of the nasal passage under the same simulation conditions, to investigate air-conditioning performance in humans, chimpanzees, and macaques. The CFD simulation showed a horizontal straight flow of inhaled air in chimpanzees and macaques, contrasting with the upward and curved flow in humans. The inhaled air is conditioned poorly in humans compared with nonhuman primates. Virtual modifications to the human external nose topology, in which the nasal vestibule and valve are modified to resemble those of chimpanzees, change the airflow to be horizontal, but have little influence on the air-conditioning performance in humans. These findings suggest that morphological variation of the nasal passage topology was only weakly sensitive to the ambient atmosphere conditions; rather, the high nasal cavity in humans was formed simply by evolutionary facial reorganization in the divergence of Homo from the other hominin lineages, impairing the air-conditioning performance. Even though the inhaled air is not adjusted well within the nasal cavity in humans, it can be fully conditioned subsequently in the pharyngeal cavity, which is lengthened in the flat-faced Homo. Thus, the air-conditioning faculty in the nasal passages was probably impaired in early Homo members, although they have survived successfully under the fluctuating climate of the Plio-Pleistocene, and then they moved “Out of Africa” to explore the more severe climates of

  14. Impaired Air Conditioning within the Nasal Cavity in Flat-Faced Homo.

    PubMed

    Nishimura, Takeshi; Mori, Futoshi; Hanida, Sho; Kumahata, Kiyoshi; Ishikawa, Shigeru; Samarat, Kaouthar; Miyabe-Nishiwaki, Takako; Hayashi, Misato; Tomonaga, Masaki; Suzuki, Juri; Matsuzawa, Tetsuro; Matsuzawa, Teruo

    2016-03-01

    We are flat-faced hominins with an external nose that protrudes from the face. This feature was derived in the genus Homo, along with facial flattening and reorientation to form a high nasal cavity. The nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. In this study, we used computational fluid dynamics (CFD) with three-dimensional topology models of the nasal passage under the same simulation conditions, to investigate air-conditioning performance in humans, chimpanzees, and macaques. The CFD simulation showed a horizontal straight flow of inhaled air in chimpanzees and macaques, contrasting with the upward and curved flow in humans. The inhaled air is conditioned poorly in humans compared with nonhuman primates. Virtual modifications to the human external nose topology, in which the nasal vestibule and valve are modified to resemble those of chimpanzees, change the airflow to be horizontal, but have little influence on the air-conditioning performance in humans. These findings suggest that morphological variation of the nasal passage topology was only weakly sensitive to the ambient atmosphere conditions; rather, the high nasal cavity in humans was formed simply by evolutionary facial reorganization in the divergence of Homo from the other hominin lineages, impairing the air-conditioning performance. Even though the inhaled air is not adjusted well within the nasal cavity in humans, it can be fully conditioned subsequently in the pharyngeal cavity, which is lengthened in the flat-faced Homo. Thus, the air-conditioning faculty in the nasal passages was probably impaired in early Homo members, although they have survived successfully under the fluctuating climate of the Plio-Pleistocene, and then they moved "Out of Africa" to explore the more severe climates of

  15. Air Conditioning Stall Phenomenon Testing, Model Development, and Simulation

    SciTech Connect

    Irminger, Philip; Rizy, D Tom; Li, Huijuan; Smith, Travis; Rice, C Keith; Li, Fangxing; Adhikari, Sarina

    2012-01-01

    Electric distribution systems are experiencing power quality issues of extended reduced voltage due to fault-induced delayed voltage recovery (FIDVR). FIDVR occurs in part because modern air conditioner (A/C) and heat pump compressor motors are much more susceptible to stalling during a voltage sag or dip such as a sub-transmission fault. They are more susceptible than older A/C compressor motors due to the low inertia of these newer and more energy efficient motors. There is a concern that these local reduced voltage events on the distribution system will become more frequent and prevalent and will combine over larger areas and challenge transmission system voltage and ultimately power grid reliability. The Distributed Energy Communications and Controls (DECC) Laboratory at Oak Ridge National Laboratory (ORNL) has been employed to (1) test, (2) characterize and (3) model the A/C stall phenomenon.

  16. Alternate working fluids for solar air conditioning applications

    NASA Technical Reports Server (NTRS)

    Evans, R. D.; Beck, J. K.

    1978-01-01

    An experimental investigation of sixteen different refrigerant-absorbent fluid pairs has been carried out in order to determine their suitability as the working fluid in a solar-powered absorption cycle air conditioner. The criteria used in the initial selection of a refrigerant-absorbent pair included: high affinity (large negative deviation from Raoult's Law), high solubility, low specific heat, low viscosity, stability, corrosive properties, safety, and cost. For practical solar considerations of a fluid pair, refrigerants were selected with low boiling points whereas absorbent fluids were selected with a boiling point considerably above that of the refrigerant. Additional restrictions are determined by the operating temperatures of the absorber and the generator; these temperatures were specified as 100 F (39 C) and 170 F (77 C). Data are presented for a few selected pressures at the specified absorber and generator temperatures.

  17. Composition changes in refrigerant blends for automotive air conditioning

    SciTech Connect

    Jetter, J.J.; Delafield, F.R.; Ng, A.S.; Ratanaphruks, K.; Tufts, M.W.

    1999-07-01

    Three refrigerant blends used to replace the chlorofluorocarbon R-12 in automotive air conditioners were evaluated for composition changes due to typical servicing and leakage. When recommended service procedures were followed, changes in blend compositions were relatively small. Small changes in blend compositions caused no significant changes in refrigeration capacities. However, when recommended procedures were not followed, changes in compositions were relatively large. The amount of change in composition and the resulting effect on performance varied among the three refrigerant blends that were tested. Of the three blends, a quaternary blend containing hydrochlorofluorocarbon R-22 had the greatest changes in composition, while a binary blend containing hydrofluorocarbon R-134a had the smallest changes in composition.

  18. Airframe Assembly, Rigging and Inspection (Course Outline), Aviation Mechanics 2 (Air Frame): 9065.02.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This document presents an outline for 135-hour course designed to familiarize the student with the manipulative skills and knowledge concerning airframe assembly, rigging, and inspection techniques in accordance with Federal Aviation Agency regulations. The aviation maintenance technician must be able to demonstrate a knowledge of assembly methods…

  19. Desiccant Enhanced Evaporative Air-Conditioning (DEVap): Evaluation of a New Concept in Ultra Efficient Air Conditioning

    SciTech Connect

    Kozubal, E.; Woods, J.; Burch, J.; Boranian, A.; Merrigan, T.

    2011-01-01

    NREL has developed the novel concept of a desiccant enhanced evaporative air conditioner (DEVap) with the objective of combining the benefits of liquid desiccant and evaporative cooling technologies into an innovative 'cooling core.' Liquid desiccant technologies have extraordinary dehumidification potential, but require an efficient cooling sink. DEVap's thermodynamic potential overcomes many shortcomings of standard refrigeration-based direct expansion cooling. DEVap decouples cooling and dehumidification performance, which results in independent temperature and humidity control. The energy input is largely switched away from electricity to low-grade thermal energy that can be sourced from fuels such as natural gas, waste heat, solar, or biofuels.

  20. 8. VIEW OF ROOM 101 (ASSEMBLY ROOM) FROM NORTHEAST CORNER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF ROOM 101 (ASSEMBLY ROOM) FROM NORTHEAST CORNER SHOWING FLEXIBLE AIR-CONDITIONING DUCT - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  1. System and method for conditioning intake air to an internal combustion engine

    SciTech Connect

    Sellnau, Mark C.

    2015-08-04

    A system for conditioning the intake air to an internal combustion engine includes a means to boost the pressure of the intake air to the engine and a liquid cooled charge air cooler disposed between the output of the boost means and the charge air intake of the engine. Valves in the coolant system can be actuated so as to define a first configuration in which engine cooling is performed by coolant circulating in a first coolant loop at one temperature, and charge air cooling is performed by coolant flowing in a second coolant loop at a lower temperature. The valves can be actuated so as to define a second configuration in which coolant that has flowed through the engine can be routed through the charge air cooler. The temperature of intake air to the engine can be controlled over a wide range of engine operation.

  2. Changes to Irradiation Conditions of VVER-1000 Surveillance Specimens Resulting from Fuel Assemblies with Greater Fuel Height

    NASA Astrophysics Data System (ADS)

    Panferov, Pavel; Kochkin, Viacheslav; Erak, Dmitry; Makhotin, Denis; Reshetnikov, Alexandr; Timofeev, Andrey

    2016-02-01

    The goal of the work was to obtain experimental data on the influence of newtype fuel assemblies with higher fuel rods on the irradiation conditions of surveillance specimens installed on the baffe of VVER-1000. For this purpose, two surveillance sets with container assemblies of the same design irradiated in reactors with different fuel assemblies in the core were investigated. Measurements of neutron dosimeters from these sets and retrospective measurements of 54Mn activity accumulated in each irradiated specimen allow a detailed distribution of the fast neutron flux in the containers to be obtained. Neutron calculations have been done using 3D discrete ordinate code KATRIN. On the basis of the obtained results, a change of the lead factor due to newtype fuel assemblies was evaluated for all types of VVER-1000 container assemblies.

  3. Air conditioning in a tropical climate: Impacts upon European residents in Darwin, Australia

    NASA Astrophysics Data System (ADS)

    Auliciems, A.; Dedear, R.

    1986-09-01

    The efficacy of current practices in air conditioning is investigated in the two monsoonal seasons in Darwin. Assessment is made of atmospheric parameters, clothing, metabolic rate. Some 1000 questionnaires are applied dealing with adaptations, health perceptions and preferences as related to air cooling and ventilation. The findings are discussed with reference to energy balance calculations and current models of psychological control in thermoregulation. The results indicate that Darwin's population is considerably overcooled, and contrary to assumptions and practice, air conditioning is not desired in office buildings during the “Dry”. In the home, air conditioning is not regarded as essential. The indications are that a rationalization of air cooling to comply with natural variability in warmth would lead to a significant reduction in energy consumption, and an overall enhancement to the health and comfort of the population through the greater ventilation rates that would be economically feasible were design temperatures lifted.

  4. Structure and morphology variation at annealing of self assembled Ag nanodots on HOPG under ambient conditions.

    NASA Astrophysics Data System (ADS)

    Senevirathne, Indrajith; Pautz, Matthew; Parks, Jeffrey; Goonewardene, Anura

    2010-03-01

    Self assembly of noble metal nanostructures on surface support under ambient conditions is interesting due to various possible plasmonic and catalytic applications. These nanostructures have altered and complex characteristics due to their outer oxide layer resulting from ambient exposure. RT (˜300K) Magnetron sputter deposited Ag, on clean, freshly cleaved HOPG was studied using ambient Scanning Tunneling Microscopy (STM), contact mode Atomic Force Microscopy (AFM) and Scanning Electron Microcopy (SEM). Surface elemental composition and distribution on the deposited system was measured with Energy Dispersive X ray Spectroscopy (EDX). Self assembled Ag nano dot structures on the surface was observed with Volmer - Weber growth mode at incremental Ag coverage. At Ag coverage of ˜32 ML nucleated nano dots observed to have ˜25nm diameter and ˜4nm in height. At an increased Ag coverage of ˜128ML, micron size super clusters were observed to coexist with the primary nano dots. Surface morphological and elemental (O and Ag) variations at annealing under successively higher temperatures will also be discussed.

  5. SCHOOL AIR CONDITIONING/CASE STUDY, MCPHERSON HIGH SCHOOL.

    ERIC Educational Resources Information Center

    OSTENBERG, JOE W.

    THE STANFORD UNIVERSITY SCHOOL PLANNING LABORATORIES CONDUCTED AN EDUCATIONAL SURVEY OF THE EDUCATIONAL NEEDS OF THE MCPHERSON CITY SCHOOLS BY STUDYING THE EXISTING CONDITIONS, LOCAL ECONOMIES, AND POTENTIAL POPULATION GROWTH. IT WAS RECOMMENDED THAT A NEW SENIOR HIGH BE BUILT TO HOUSE 700-750 STUDENTS, THE ANTICIPATED ENROLLMENT 10 YEARS AFTER…

  6. 40 CFR 86.165-12 - Air conditioning idle test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... This test is designed to determine the air conditioning-related CO2 emission value, in grams per minute... this stabilization. (3) Immediately after the preconditioning, turn off any cooling fans, if present... but set the fan speed to the lowest setting that continues to provide air flow. Recirculation shall...

  7. Air Conditioning, Heating, and Ventilating: Construction, Supervision, and Inspection. Course of Study.

    ERIC Educational Resources Information Center

    Messer, John D.

    This course of study on air conditioning, heating, and ventilating is part of a construction, supervision, and inspection series, which provides instructional materials for community or junior college technical courses in the inspection program. Material covered pertains to: piping and piping systems; air movers; boilers; heat exchangers; cooling…

  8. Temperature and Humidity Independent Control Research on Ground Source Heat Pump Air Conditioning System

    NASA Astrophysics Data System (ADS)

    Chen, G.; Wang, L. L.

    Taking green demonstration center building air conditioning system as an example, this paper presents the temperature and humidity independent control system combined with ground source heat pump system, emphasis on the design of dry terminal device system, fresh air system and ground source heat pump system.

  9. 24 CFR 3280.813 - Outdoor outlets, fixtures, air-conditioning equipment, etc.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Outdoor outlets, fixtures, air... Electrical Systems § 3280.813 Outdoor outlets, fixtures, air-conditioning equipment, etc. (a) Outdoor fixtures and equipment shall be listed for use in wet locations, except that if located on the underside...

  10. 24 CFR 3280.813 - Outdoor outlets, fixtures, air-conditioning equipment, etc.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Outdoor outlets, fixtures, air... Electrical Systems § 3280.813 Outdoor outlets, fixtures, air-conditioning equipment, etc. Link to an amendment published at 78 FR 73992, Dec. 9, 2013. (a) Outdoor fixtures and equipment shall be listed for...

  11. 24 CFR 3280.813 - Outdoor outlets, fixtures, air-conditioning equipment, etc.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Outdoor outlets, fixtures, air... Electrical Systems § 3280.813 Outdoor outlets, fixtures, air-conditioning equipment, etc. (a) Outdoor fixtures and equipment shall be listed for use in wet locations, except that if located on the underside...

  12. 24 CFR 3280.813 - Outdoor outlets, fixtures, air-conditioning equipment, etc.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Outdoor outlets, fixtures, air... Electrical Systems § 3280.813 Outdoor outlets, fixtures, air-conditioning equipment, etc. (a) Outdoor fixtures and equipment shall be listed for use in wet locations, except that if located on the underside...

  13. 24 CFR 3280.813 - Outdoor outlets, fixtures, air-conditioning equipment, etc.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Outdoor outlets, fixtures, air... Electrical Systems § 3280.813 Outdoor outlets, fixtures, air-conditioning equipment, etc. (a) Outdoor fixtures and equipment shall be listed for use in wet locations, except that if located on the underside...

  14. Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

    NASA Technical Reports Server (NTRS)

    Ahearn, D. G.; Simmons, R. B.; Switzer, K. F.; Ajello, L.; Pierson, D. L.

    1991-01-01

    Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

  15. Influence of Boundary Conditions on Simulated U.S. Air Quality

    EPA Science Inventory

    One of the key inputs to regional-scale photochemical models frequently used in air quality planning and forecasting applications are chemical boundary conditions representing background pollutant concentrations originating outside the regional modeling domain. A number of studie...

  16. Fuel Savings and Emission Reductions from Next-Generation Mobile Air Conditioning Technology in India: Preprint

    SciTech Connect

    Chaney, L.; Thundiyil, K.; Chidambaram, S.; Abbi, Y. P.; Anderson, S.

    2007-05-01

    This paper quantifies the mobile air-conditioning fuel consumption of the typical Indian vehicle, exploring potential fuel savings and emissions reductions these systems for the next generation of vehicles.

  17. Evaluating Membrane Processes for Air Conditioning; Highlights in Research and Development, NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This NREL Highlight discusses a recent state-of-the-art review of membrane processes for air conditioning that identifies future research opportunities. This highlight is being developed for the June 2015 S&T Alliance Board meeting.

  18. Solar technology assessment project. Volume 4: Solar air conditioning: Active, hybrid and passive

    NASA Astrophysics Data System (ADS)

    Yellott, J. I.

    1981-04-01

    The status of absorption cycle solar air conditioning and the Rankine cycle solar cooling system is reviewed. Vapor jet ejector chillers, solar pond based cooling, and photovoltaic compression air conditioning are also briefly discussed. Hybrid solar cooling by direct and indirect evaporative cooling, and dehumidification by desiccation are described and discussed. Passive solar cooling by convective and radiative processes, evaporative cooling by passive processes, and cooling with roof ponds and movable insulation are reviewed. Federal and state involvement in solar cooling is discussed.

  19. Contribution of air conditioning adoption to future energy use under global warming.

    PubMed

    Davis, Lucas W; Gertler, Paul J

    2015-05-12

    As household incomes rise around the world and global temperatures go up, the use of air conditioning is poised to increase dramatically. Air conditioning growth is expected to be particularly strong in middle-income countries, but direct empirical evidence is scarce. In this paper we use high-quality microdata from Mexico to describe the relationship between temperature, income, and air conditioning. We describe both how electricity consumption increases with temperature given current levels of air conditioning, and how climate and income drive air conditioning adoption decisions. We then combine these estimates with predicted end-of-century temperature changes to forecast future energy consumption. Under conservative assumptions about household income, our model predicts near-universal saturation of air conditioning in all warm areas within just a few decades. Temperature increases contribute to this surge in adoption, but income growth by itself explains most of the increase. What this will mean for electricity consumption and carbon dioxide emissions depends on the pace of technological change. Continued advances in energy efficiency or the development of new cooling technologies could reduce the energy consumption impacts. Similarly, growth in low-carbon electricity generation could mitigate the increases in carbon dioxide emissions. However, the paper illustrates the enormous potential impacts in this sector, highlighting the importance of future research on adaptation and underscoring the urgent need for global action on climate change.

  20. Contribution of air conditioning adoption to future energy use under global warming.

    PubMed

    Davis, Lucas W; Gertler, Paul J

    2015-05-12

    As household incomes rise around the world and global temperatures go up, the use of air conditioning is poised to increase dramatically. Air conditioning growth is expected to be particularly strong in middle-income countries, but direct empirical evidence is scarce. In this paper we use high-quality microdata from Mexico to describe the relationship between temperature, income, and air conditioning. We describe both how electricity consumption increases with temperature given current levels of air conditioning, and how climate and income drive air conditioning adoption decisions. We then combine these estimates with predicted end-of-century temperature changes to forecast future energy consumption. Under conservative assumptions about household income, our model predicts near-universal saturation of air conditioning in all warm areas within just a few decades. Temperature increases contribute to this surge in adoption, but income growth by itself explains most of the increase. What this will mean for electricity consumption and carbon dioxide emissions depends on the pace of technological change. Continued advances in energy efficiency or the development of new cooling technologies could reduce the energy consumption impacts. Similarly, growth in low-carbon electricity generation could mitigate the increases in carbon dioxide emissions. However, the paper illustrates the enormous potential impacts in this sector, highlighting the importance of future research on adaptation and underscoring the urgent need for global action on climate change. PMID:25918391

  1. Influence of Ventilation Ratio on Desiccant Air Conditioning System's Efficiency Performance

    NASA Astrophysics Data System (ADS)

    Tran, Thien Nha; Akisawa, Atsushi; Kashiwagi, Takao; Hamamoto, Yoshinori

    Ventilation air is a concern for engineers since ventilated air controls indoor air contamination; additional ventilation, however, increases the energy consumption of buildings. The study investigates the energy efficiency performance of the desiccant dehumidification air conditioning system in the context of ventilation for a hot-humid climate such as summer in Japan. The investigation focuses on the variable ratio of ventilation air as required by the application of air conditioning system. The COP of the desiccant air conditioning system is determined. The evaluation is subsequently performed by comparing the desiccant based system with the conventional absorption cooling system and the vapor compression cooling system. Based on 12 desiccant rotor simulations, it is found that the desiccant regeneration temperature required varies between 47°C to 85°C as ventilation ratio increases from 0. 0 to 100%, and up to 52. 5°C as the ventilation ratio achieves 14%. The heat required for regenerating desiccant accounts for 55% and higher of the system's total heat consumption; the system is expected to be energy efficient by using wasted heat from the absorption chiller for desiccant regeneration; and its energy efficiency expands as the ratio of ventilation air rises above 15% compared with the conventional absorption cooling system. The energy efficiency also benefits as the ratio rises beyond 70% against the conventional vapor compression cooling system.

  2. A statistical model for characterizing common air pollutants in air-conditioned offices

    NASA Astrophysics Data System (ADS)

    Wong, L. T.; Mui, K. W.; Hui, P. S.

    Maintaining acceptable indoor air quality (IAQ) for a healthy environment is of primary concern, policymakers have developed different strategies to address the performance of it based on proper assessment methodologies and monitoring plans. It could be cost prohibitive to sample all toxic pollutants in a building. In search of a more manageable number of parameters for cost-effective IAQ assessment, this study investigated the probable correlations among the 12 indoor environmental parameters listed in the IAQ certification scheme of the Hong Kong Environment Protection Department (HKEPD) in 422 Hong Kong offices. These 12 parameters consists of nine indoor air pollutants: carbon dioxide (CO 2), carbon monoxide (CO), respirable suspended particulates (RSP), nitrogen dioxide (NO 2), ozone (O 3), formaldehyde (HCHO), total volatile organic compounds (TVOC), radon (Rn), airborne bacteria count (ABC); and three thermal comfort parameters: temperature ( T), relative humidity (RH) and air velocity ( V). The relative importance of the correlations derived, from largest to smallest loadings, was ABC, Rn, CO, RH, RSP, CO 2, TVOC, O 3, T, V, NO 2 and HCHO. Together with the mathematical expressions derived, an alternative sampling protocol for IAQ assessment with the three 'most representative and independent' parameters namely RSP, CO 2 and TVOC measured in an office environment was proposed. The model validity was verified with on site measurements from 43 other offices in Hong Kong. The measured CO 2, RSP and TVOC concentrations were used to predict the probable levels of the other nine parameters and good agreement was found between the predictions and measurements. This simplified protocol provides an easy tool for performing IAQ monitoring in workplaces and will be useful for determining appropriate mitigation measures to finally honor the certification scheme in a cost-effective way.

  3. Fungal colonization of air filters for use in heating, ventilating, and air conditioning (HVAC) systems.

    PubMed

    Simmons, R B; Crow, S A

    1995-01-01

    New and used cellulosic air filters for HVAC systems including those treated with antimicrobials were suspended in vessels with a range of relative humidities (55-99%) and containing non-sterile potting soil which stimulates fungal growth. Most filters yielded fungi prior to suspension in the chambers but only two of 14 nontreated filters demonstrated fungal colonization following use in HVAC systems. Filters treated with antimicrobials, particularly a phosphated amine complex, demonstrated markedly less fungal colonization than nontreated filters. In comparison with nontreated cellulosic filters, fungal colonization of antimicrobial-treated cellulosic filters was selective and delayed.

  4. Modeling validation and control analysis for controlled temperature and humidity of air conditioning system.

    PubMed

    Lee, Jing-Nang; Lin, Tsung-Min; Chen, Chien-Chih

    2014-01-01

    This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14 °C, 0006 kg(w)/kg(da) in steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system.

  5. Modeling Validation and Control Analysis for Controlled Temperature and Humidity of Air Conditioning System

    PubMed Central

    Lee, Jing-Nang; Lin, Tsung-Min

    2014-01-01

    This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14°C, 0006 kgw/kgda in steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system. PMID:25250390

  6. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  7. Experimental investigation on performance of ice storage air-conditioning system with separate heat pipe

    SciTech Connect

    Fang, Guiyin; Liu, Xu; Wu, Shuangmao

    2009-11-15

    An experimental study on operation performance of ice storage air-conditioning system with separate helical heat pipe is conducted in this paper. The experimental system of ice storage air-conditioning system with separate heat pipe is set up. The performance parameters such as the evaporation pressure and the condensation pressure of refrigeration system, the refrigeration capacity and the COP (coefficient of performance) of the system, the IPF (ice packing factor) and the cool storage capacity in the cool storage tank during charging period, and the cool discharge rate and the cool discharge capacity in the cool storage tank, the outlet water temperature in the cool storage tank and the outlet air temperature in room unit during discharging period are investigated. The experimental results show that the ice storage air-conditioning system with separate helical heat pipe can stably work during charging and discharging period. This indicates that the ice storage air-conditioning system with separate helical heat pipe is well adapted to cool storage air-conditioning systems in building. (author)

  8. 75 FR 50688 - Special Conditions: Erickson Air-Crane Incorporated S-64E and S-64F Rotorcraft

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-17

    ... Federal Aviation Administration 14 CFR Parts 21 and 29 Special Conditions: Erickson Air-Crane Incorporated... special conditions. SUMMARY: These special conditions are issued for the Erickson Air-Crane Incorporated (Erickson Air-Crane) model S-64E and S-64F rotorcraft. These rotorcraft have novel or unusual...

  9. Correction of Temperatures of Air-Cooled Engine Cylinders for Variation in Engine and Cooling Conditions

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Pinkel, Benjamin; Ellerbrock, Herman H , Jr

    1939-01-01

    Factors are obtained from semiempirical equations for correcting engine-cylinder temperatures for variation in important engine and cooling conditions. The variation of engine temperatures with atmospheric temperature is treated in detail, and correction factors are obtained for various flight and test conditions, such as climb at constant indicated air speed, level flight, ground running, take-off, constant speed of cooling air, and constant mass flow of cooling air. Seven conventional air-cooled engine cylinders enclosed in jackets and cooled by a blower were tested to determine the effect of cooling-air temperature and carburetor-air temperature on cylinder temperatures. The cooling air temperature was varied from approximately 80 degrees F. to 230 degrees F. and the carburetor-air temperature from approximately 40 degrees F. to 160 degrees F. Tests were made over a large range of engine speeds, brake mean effective pressures, and pressure drops across the cylinder. The correction factors obtained experimentally are compared with those obtained from the semiempirical equations and a fair agreement is noted.

  10. Effects of suspension of air-conditioning on airtight-type racks.

    PubMed

    Kanzaki, M; Fujieda, M; Furukawa, T

    2001-10-01

    Although isolation racks are superior to open-type racks in terms of securing breeding conditions for laboratory animals, the contingency-proofing capability of the former has yet to be determined. Therefore, from the view of risk management, we studied the environmental change in isolation racks by forcibly suspending ventilation and air-conditioning and confirming the maximal time length for complete recovery to the original condition after restarting their operations. The isolation racks were placed in a room that was equipped with an independent air-conditioning system. When the inside condition of the racks reached 22-24 degrees C and 59-64% of relative humidity, the air-conditioning and ventilation were forcibly suspended and the subsequent temperature, relative humidity, ammonium and CO2 concentrations in the racks were measured over time. We found that after suspending the air-conditioning and ventilation, it took 40-60 min for temperature, and about 10 min for relative humidity to exceed the maximum values (temperature and relative humidity) referred to in the Showa 58 Nenban Guideline Jikken Doubutsu Shisetsu no Kenchiku oyobi Setsubi (Guidelines of buildings and facilities for experimental animals in Japan; Year 1983 edition). After 17 hr 25 min of the suspension of air-conditioning and ventilation, two rats were found dead. Then, the air-conditioning and ventilation were restarted. It took about 2 hr for temperature, and 50 min for relative humidity to regain the guideline values. The ammonium concentration stayed within the guideline value with a maximum concentration of 2 ppm in the experimental period, whereas the CO2 concentration was found to exceed 9% at the time of animal death.

  11. Improving Forecast Skill by Assimilation of Quality-controlled AIRS Temperature Retrievals under Partially Cloudy Conditions

    NASA Technical Reports Server (NTRS)

    Reale, O.; Susskind, J.; Rosenberg, R.; Brin, E.; Riishojgaard, L.; Liu, E.; Terry, J.; Jusem, J. C.

    2007-01-01

    The National Aeronautics and Space Administration (NASA) Atmospheric Infrared Sounder (AIRS) on board the Aqua satellite has been long recognized as an important contributor towards the improvement of weather forecasts. At this time only a small fraction of the total data produced by AIRS is being used by operational weather systems. In fact, in addition to effects of thinning and quality control, the only AIRS data assimilated are radiance observations of channels unaffected by clouds. Observations in mid-lower tropospheric sounding AIRS channels are assimilated primarily under completely clear-sky conditions, thus imposing a very severe limitation on the horizontal distribution of the AIRS-derived information. In this work it is shown that the ability to derive accurate temperature profiles from AIRS observations in partially cloud-contaminated areas can be utilized to further improve the impact of AIRS observations in a global model and forecasting system. The analyses produced by assimilating AIRS temperature profiles obtained under partial cloud cover result in a substantially colder representation of the northern hemisphere lower midtroposphere at higher latitudes. This temperature difference has a strong impact, through hydrostatic adjustment, in the midtropospheric geopotential heights, which causes a different representation of the polar vortex especially over northeastern Siberia and Alaska. The AIRS-induced anomaly propagates through the model's dynamics producing improved 5-day forecasts.

  12. 40 CFR 86.165-12 - Air conditioning idle test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... conditioning system automatically defaults to a recirculation mode when set to maximum cooling. Continue idling... system defaults to a recirculation mode when set to maximum cooling and maintains recirculation with the... at idle when CO2 emissions are measured without any air conditioning systems operating, followed by...

  13. 40 CFR 86.167-17 - AC17 Air Conditioning Emissions Test Procedure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.167-17 AC17 Air Conditioning...-conditioning cycle, a 30-minute soak period under simulated solar heat, followed by measurement of emissions over an SC03 drive cycle and a Highway Fuel Economy Driving Schedule (HFET) drive cycle. The vehicle...

  14. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... conditioning test simulations. 86.162-03 Section 86.162-03 Protection of Environment ENVIRONMENTAL PROTECTION... ENGINES Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles and New Light-Duty... alternative air conditioning test simulations. (a) Upon petition from a manufacturer or upon the Agency's...

  15. Bacteriology of Air-Conditioning Ducts with Special Reference to Operating Rooms

    PubMed Central

    Warner, Peter; Doherty, Jane

    1963-01-01

    The number of bacteria in air, before filtration with five different easily available filters in the low positive-pressure type of airconditioning system of the Winnipeg General Hospital, was between 3 and 4/cu. ft., and after filtration between 1 and 2/cu. ft. with all types of filters. Cl. welchii contributed about 1% and Staph. pyogenes about 0.1% of this total. Sampling the exhaust air from an operating room during an operation showed that the bacterial count fluctuated with the degree of activity in the room and was from two to 10 times as high as in the air delivered to the room. Atlhough every reasonable attempt should be made to diminish the bacterial count of air in hospitals, if much energy and money is to be spent it would probably be wiser to investigate sources of hospital infection other than the type of air-conditioning system described in this report. PMID:13998955

  16. Air Conditioning with Magnetic Refrigeration : An Efficient, Green Compact Cooling System Using Magnetic Refrigeration

    SciTech Connect

    2010-09-01

    BEETIT Project: Astronautics is developing an air conditioning system that relies on magnetic fields. Typical air conditioners use vapor compression to cool air. Vapor compression uses a liquid refrigerant to circulate within the air conditioner, absorb the heat, and pump the heat out into the external environment. Astronautics’ design uses a novel property of certain materials, called “magnetocaloric materials”, to achieve the same result as liquid refrigerants. These magnetocaloric materials essentially heat up when placed within a magnetic field and cool down when removed, effectively pumping heat out from a cooler to warmer environment. In addition, magnetic refrigeration uses no ozone-depleting gases and is safer to use than conventional air conditioners which are prone to leaks.

  17. Spent fuel dry storage technology development: fuel temperature measurements under imposed dry storage conditions (I kW PWR spent fuel assembly)

    SciTech Connect

    Unterzuber, R.; Wright, J.B.

    1980-09-01

    A spent fuel assembly temperature test under imposed dry storage conditions was conducted at the Engine Maintenance Assembly and Disassembly (E-MAD) facility on the Nevada Test Site in support of spent fuel dry storage technology development. This document presents the test data and results obtained from an approximately 1.0 kW decay heat level PWR spent fuel assembly. A spent fuel test apparatus was designed to utilize a representative stainless steel spent fuel canister, a canister lid containing internal temperature instrumentation to measure fuel cladding temperatures, and a carbon steel liner that encloses the canister and lid. Electrical heaters along the liner length, on the lid, and below the canister are used to impose dry storage canister temperature profiles. Temperature instrumentation is provided on the liner and canister. The liner and canister are supported by a test stand in one of the large hot cells (West Process Cell) inside E-MAD. Fuel temperature measurements have been performed using imposed canister temperature profiles from the electrically heated and spent fuel drywell tests being conducted at E-MAD as well as for four constant canister temperature profiles, each with a vacuum, helium and air backfill. Computer models have been utilized in conjunction with the test to predict the thermal response of the fuel cladding. Computer predictions are presented, and they show good agreement with the test data.

  18. Design and demonstration of a storage-assisted air conditioning system

    NASA Astrophysics Data System (ADS)

    Rizzuto, J. E.

    1981-03-01

    The system is a peak-shaving system designed to provide a levelized air conditioning load. The system also requires minimum air conditioner and thermal storage capacity. The storage-assisted air conditioning system uses a Glauber's salt-based phase change material in sausage like containers called CHUBS. The CHUBS are two (2) inches in diameter and 20 inches long. They are stacked in modules of 64 CHUBS which are appropriately spaced and oriented in the storage system so that air may pass perpendicular to the long axis of the CHUBS. The phase change material, has a thermal storage capacity in the range of 45 to 50 Btu/lb and a transition temperature of approximately 55 F.

  19. Self-Assembly of Single-Sized and Binary Colloidal Particles at Air/Water Interface by Surface Confinement and Water Discharge.

    PubMed

    Lotito, Valeria; Zambelli, Tomaso

    2016-09-20

    We present an innovative apparatus allowing self-assembly at air/water interface in a smooth and reproducible way. The combination of water discharge and surface confinement of the area over which self-assembly takes place allows transfer of the assembled monolayer without any risk of damage to the colloidal crystal. As we demonstrate, the designed approach offers remarkable advantages in terms of cost and robustness compared to state-of-the art methods and is suitable for the fabrication of highly ordered monolayers even for more challenging assembly experiments such as transfer on rough substrates or assembly of binary colloids. Hence, our apparatus represents a significant headway toward high scale production of large area colloidal crystals. For the binary colloid assembly experiments, we also report the first experimental demonstration of a morphology based on the alternation of three and four small particles in the interstices between large particles. PMID:27574790

  20. Self-Assembly of Single-Sized and Binary Colloidal Particles at Air/Water Interface by Surface Confinement and Water Discharge.

    PubMed

    Lotito, Valeria; Zambelli, Tomaso

    2016-09-20

    We present an innovative apparatus allowing self-assembly at air/water interface in a smooth and reproducible way. The combination of water discharge and surface confinement of the area over which self-assembly takes place allows transfer of the assembled monolayer without any risk of damage to the colloidal crystal. As we demonstrate, the designed approach offers remarkable advantages in terms of cost and robustness compared to state-of-the art methods and is suitable for the fabrication of highly ordered monolayers even for more challenging assembly experiments such as transfer on rough substrates or assembly of binary colloids. Hence, our apparatus represents a significant headway toward high scale production of large area colloidal crystals. For the binary colloid assembly experiments, we also report the first experimental demonstration of a morphology based on the alternation of three and four small particles in the interstices between large particles.

  1. Minor contributions of the maxillary sinus to the air-conditioning performance in macaque monkeys.

    PubMed

    Mori, Futoshi; Hanida, Sho; Kumahata, Kiyoshi; Miyabe-Nishiwaki, Takako; Suzuki, Juri; Matsuzawa, Teruo; Nishimura, Takeshi D

    2015-08-01

    The nasal passages mainly adjust the temperature and humidity of inhaled air to reach the alveolar condition required in the lungs. By contrast to most other non-human primates, macaque monkeys are distributed widely among tropical, temperate and subarctic regions, and thus some species need to condition the inhaled air in cool and dry ambient atmospheric areas. The internal nasal anatomy is believed to have undergone adaptive modifications to improve the air-conditioning performance. Furthermore, the maxillary sinus (MS), an accessory hollow communicating with the nasal cavity, is found in macaques, whereas it is absent in most other extant Old World monkeys, including savanna monkeys. In this study, we used computational fluid dynamics simulations to simulate the airflow and heat and water exchange over the mucosal surface in the nasal passage. Using the topology models of the nasal cavity with and without the MS, we demonstrated that the MS makes little contribution to the airflow pattern and the air-conditioning performance within the nasal cavity in macaques. Instead, the inhaled air is conditioned well in the anterior portion of the nasal cavity before reaching the MS in both macaques and savanna monkeys. These findings suggest that the evolutionary modifications and coetaneous variations in the nasal anatomy are rather independent of transitions and variations in the climate and atmospheric environment found in the habitats of macaques.

  2. Ruggedizing infrared integrated Dewar-detector assemblies for harsh environmental conditions

    NASA Astrophysics Data System (ADS)

    Veprik, Alexander; Ashush, Nataniel; Shlomovich, Baruch; Oppenhaim, Yaakov; Gridish, Yaakov; Kahanov, Ezra; Koifman, Alina; Tuito, Avi

    2014-06-01

    Cryogenically cooled infrared electro-optical payloads have to operate and survive frequent exposure to harsh vibrational and shock conditions typical of the modern battlefield. This necessitates the development of special approaches to ruggedizing their sensitive components. The ruggedization requirement holds true specifically for Integrated Dewar-Detector Assemblies (IDDA), where the infrared Focal Plane Array (FPA) is usually supported by a thin-walled cold finger enveloped by an evacuated tubular Dewar. Without sufficient ruggedization, harsh environmental vibration may give rise to structural resonance responses resulting in spoiled image quality and even mechanical fractures due to material fatigue. The authors present their approach for the ruggedization of the IDDA by attaching the FPA to a semi-rigid support extending from the dynamically damped Dewar envelope. A mathematical model relies on an experimentally evaluated set of frequency response functions for a reference system and a lumped model of a wideband dynamic absorber. By adding only 2% to the weight of the IDDA, the authors have managed to attenuate the relative deflection and absolute acceleration of the FPA by a factor of 3. The analytical predictions are in full agreement with experiment.

  3. Improved particle impactor assembly for size selective high volume air sampler

    DOEpatents

    Langer, G.

    1987-03-23

    Air containing entrained particulate matter is directed through a plurality of parallel, narrow, vertically oriented apertures of an inlet element toward an adjacently located, relatively large, dust impaction surface preferably covered with an adhesive material. The air flow turns over the impaction surface, leaving behind, the relatively larger particles and passes through two elongate apertures defining the outer bounds of the impaction collection surface to pass through divergent passages which slow down and distribute the air flow, with entrained smaller particles, over a fine filter element that separates the fine particles from the air. By appropriate selection of dimensions and the number of inlet apertures air flow through the inlet element is provided a nonuniform velocity distribution with the lower velocities being obtained near the center of the inlet apertures, to separate out particles larger than a certain predetermined size on the impaction collection surface. The impaction collection surface, even in a moderately sized apparatus, is thus relatively large and permits the prolonged sampling of air for periods extending to four weeks. 6 figs.

  4. [Transfer of organisms during exchange of heat and moisture in air conditioning installations (author's transl)].

    PubMed

    Beckert, J; Sinner, G

    1975-07-01

    With the exhaust air from ventilation and air conditioning installations escaping into the open, the heat content is also lost which fresh air from outside obtains at considerable expense of energy and technical equipment. The heat content, on the other hand, consists of about equal proportions of sensible heat and latent heat which is associated with the moisture content of the air. In order to regain the heat content of the escaping air so as to be able to use it again - and this is becoming increasingly important with rising energy costs - heat exchangers are necessary which remove the heat content from the exhaust air and transfer it to the fresh air from outside. With the high proportion of latent heat, this energy exchange is only effective if the latent heat can also be regained. For this purpose it is essential to have exchange surfaces which store and transfer both heat and moisture. To achieve this they must come into contact with the exhaust air stream and the fresh air stream alternately. Technically, this is done in a simple way by resolving rotor-like storage material. But a rigid separation of the air streams is no longer possible. Even if it is known that there are very highly developed sealing elements between the fixed and moving parts, the question whether particles from the exhaust air can get into the newly introduced outside air through the rotating storage material still gains in importance in certain types of usuage. For example, this is of importance for hospitals, especially in the operation areas in which air conditioning is desirable for 24 hours daily on hygienic grounds, but also in schools and offices where the present normal practice, for economic reasons, of recirculating air is to be avoided to stop the transference of infections pathogens and odours. In various places, experiments have been carried out earlier with heat exchangers consisting of asbestos board and with rotating storage material coated with lithium chloride and a

  5. Impact of the electric compressor for automotive air conditioning system on fuel consumption and performance analysis

    NASA Astrophysics Data System (ADS)

    Zulkifli, A. A.; Dahlan, A. A.; Zulkifli, A. H.; Nasution, H.; Aziz, A. A.; Perang, M. R. M.; Jamil, H. M.; Misseri, M. N.

    2015-12-01

    Air conditioning system is the biggest auxiliary load in a vehicle where the compressor consumed the largest. Problem with conventional compressor is the cooling capacity cannot be control directly to fulfill the demand of thermal load inside vehicle cabin. This study is conducted experimentally to analyze the difference of fuel usage and air conditioning performance between conventional compressor and electric compressor of the air conditioning system in automobile. The electric compressor is powered by the car battery in non-electric vehicle which the alternator will recharge the battery. The car is setup on a roller dynamometer and the vehicle speed is varied at 0, 30, 60, 90 and 110 km/h at cabin temperature of 25°C and internal heat load of 100 and 400 Watt. The results shows electric compressor has better fuel consumption and coefficient of performance compared to the conventional compressor.

  6. Carbon Dioxide and Ionic Liquid Refrigerants: Compact, Efficient Air Conditioning with Ionic Liquid-Based Refrigerants

    SciTech Connect

    2010-10-01

    BEETIT Project: Notre Dame is developing an air-conditioning system with a new ionic liquid and CO2 as the working fluid. Synthetic refrigerants used in air conditioning and refrigeration systems are potent GHGs and can trap 1,000 times more heat in the atmosphere than CO2 alone—making CO2 an attractive alternative for synthetic refrigerants in cooling systems. However, operating cooling systems with pure CO2 requires prohibitively high pressures and expensive hardware. Notre Dame is creating a new fluid made of CO2 and ionic liquid that enables the use of CO2 at low pressures and requires minimal changes to existing hardware and production lines. This new fluid also produces no harmful emissions and can improve the efficiency of air conditioning systems— enabling new use of CO2 as a refrigerant in cooling systems.

  7. An Expert Fault Diagnosis System for Vehicle Air Conditioning Product Development

    NASA Astrophysics Data System (ADS)

    Tan, C. F.; Tee, B. T.; Khalil, S. N.; Chen, W.; Rauterberg, G. W. M.

    2015-09-01

    The paper describes the development of the vehicle air-conditioning fault diagnosis system in automotive industries with expert system shell. The main aim of the research is to diagnose the problem of new vehicle air-conditioning system development process and select the most suitable solution to the problems. In the vehicle air-conditioning manufacturing industry, process can be very costly where an expert and experience personnel needed in certain circumstances. The expert of in the industry will retire or resign from time to time. When the expert is absent, their experience and knowledge is difficult to retrieve or lost forever. Expert system is a convenient method to replace expert. By replacing the expert with expert system, the accuracy of the processes will be increased compared to the conventional way. Therefore, the quality of product services that are produced will be finer and better. The inputs for the fault diagnosis are based on design data and experience of the engineer.

  8. Research on Using the Naturally Cold Air and the Snow for Data Center Air-conditioning, and Humidity Control

    NASA Astrophysics Data System (ADS)

    Tsuda, Kunikazu; Tano, Shunichi; Ichino, Junko

    To lower power consumption has becomes a worldwide concern. It is also becoming a bigger area in Computer Systems, such as reflected by the growing use of software-as-a-service and cloud computing whose market has increased since 2000, at the same time, the number of data centers that accumulates and manages the computer has increased rapidly. Power consumption at data centers is accounts for a big share of the entire IT power usage, and is still rapidly increasing. This research focuses on the air-conditioning that occupies accounts for the biggest portion of electric power consumption by data centers, and proposes to develop a technique to lower the power consumption by applying the natural cool air and the snow for control temperature and humidity. We verify those effectiveness of this approach by the experiment. Furthermore, we also examine the extent to which energy reduction is possible when a data center is located in Hokkaido.

  9. SUMMARY OF ELECTRIC SERVICE COSTS FOR TOTALLY AIR CONDITIONED SCHOOLS PREPARED FOR HOUSTON INDEPENDENT SCHOOL DISTRICT, MAY 31, 1967.

    ERIC Educational Resources Information Center

    WHITESIDES, M.M.

    THIS REPORT IS A COMPILATION OF DATA ON ELECTRIC AIR CONDITIONING COSTS, OPERATIONS AND MAINTENANCE. AIR CONDITIONING UNITS ARE COMPARED IN TERMS OF ELECTRIC VERSUS NON-ELECTRIC, AUTOMATIC VERSUS OPERATED, AIR COOLED VERSUS WATER COOLED, RECIPROCATING VERSUS CENTRIFUGAL COMPRESSORS, SPACE AND NOISE, REHEAT, MAINTENANCE AND ORIGINAL COST. DATA ARE…

  10. Conditioning the middle ear reflex at sensation levels below reflex threshold: air jet and electrical stimulation.

    PubMed

    McDaniel-Bacon, L; Fulton, R T; Laskowski, R P

    1980-01-01

    An ABAB functional analysis, conditioning and generalization, design was used in 3 experiments (2 were formal studies and 1 was empirical in nature) to investigate the conditionability of the middle ear reflex. The conditioned stimuli were subreflex threshold pure tones of various frequencies and intensities. The unconditioned stimulus (UCS) was an auricular air jet to the contralateral ear in the first experiment and cutaneous electrical stimulation to the ipsolateral, probe ear in the last 2 experiments. Reflexes were monitored by an otoadmittance meter, storage oscilloscope, and strip chart recorder. In the first experiment (air jet UCS), no subjects met the conditioning criterion within the maximum presentation of 400 paired trials, despite pilot evidence which indicated conditioning was feasible. In the second experiment (electrical stimulation UCS), 2 subjects met conditioning criterion; however, only one subject reconditioned and demonstrated partial generalization to other conditioned stimuli. In the third experiment (electrical stimulation UCS), one of 3 subjects who had previously been unconditionable with the air jet UCS met conditioning and reconditioning criterion and demonstrated partial generalization. Results indicate that the middle ear reflex can be conditioned to be elicited by subreflex threshold pure tones, however, results are limited.

  11. Optimization of microwave-assisted hot air drying conditions of okra using response surface methodology.

    PubMed

    Kumar, Deepak; Prasad, Suresh; Murthy, Ganti S

    2014-02-01

    Okra (Abelmoschus esculentus) was dried to a moisture level of 0.1 g water/g dry matter using a microwave-assisted hot air dryer. Response surface methodology was used to optimize the drying conditions based on specific energy consumption and quality of dried okra. The drying experiments were performed using a central composite rotatable design for three variables: air temperature (40-70 °C), air velocity (1-2 m/s) and microwave power level (0.5-2.5 W/g). The quality of dried okra was determined in terms of color change, rehydration ratio and hardness of texture. A second-order polynomial model was well fitted to all responses and high R(2) values (>0.8) were observed in all cases. The color change of dried okra was found higher at high microwave power and air temperatures. Rehydration properties were better for okra samples dried at higher microwave power levels. Specific energy consumption decreased with increase in microwave power due to decrease in drying time. The drying conditions of 1.51 m/s air velocity, 52.09 °C air temperature and 2.41 W/g microwave power were found optimum for product quality and minimum energy consumption for microwave-convective drying of okra.

  12. Keeping cool: use of air conditioning by australians with multiple sclerosis.

    PubMed

    Summers, Michael P; Simmons, Rex D; Verikios, George

    2012-01-01

    Despite the known difficulties many people with MS have with high ambient temperatures, there are no reported studies of air conditioning use and MS. This study systematically examined air conditioner use by Australians with MS. A short survey was sent to all participants in the Australian MS Longitudinal Study cohort with a response rate of 76% (n = 2,385). Questions included hours of air-conditioner use, areas cooled, type and age of equipment, and the personal effects of overheating. Air conditioners were used by 81.9% of respondents, with an additional 9.6% who could not afford an air conditioner. Regional and seasonal variation in air conditioning use was reported, with a national annual mean of 1,557 hours running time. 90.7% reported negative effects from overheating including increased fatigue, an increase in other MS symptoms, reduced household and social activities, and reduced work capacity. Households that include people with MS spend between 4 and 12 times more on keeping cool than average Australian households. PMID:22548176

  13. Optimization of microwave-assisted hot air drying conditions of okra using response surface methodology.

    PubMed

    Kumar, Deepak; Prasad, Suresh; Murthy, Ganti S

    2014-02-01

    Okra (Abelmoschus esculentus) was dried to a moisture level of 0.1 g water/g dry matter using a microwave-assisted hot air dryer. Response surface methodology was used to optimize the drying conditions based on specific energy consumption and quality of dried okra. The drying experiments were performed using a central composite rotatable design for three variables: air temperature (40-70 °C), air velocity (1-2 m/s) and microwave power level (0.5-2.5 W/g). The quality of dried okra was determined in terms of color change, rehydration ratio and hardness of texture. A second-order polynomial model was well fitted to all responses and high R(2) values (>0.8) were observed in all cases. The color change of dried okra was found higher at high microwave power and air temperatures. Rehydration properties were better for okra samples dried at higher microwave power levels. Specific energy consumption decreased with increase in microwave power due to decrease in drying time. The drying conditions of 1.51 m/s air velocity, 52.09 °C air temperature and 2.41 W/g microwave power were found optimum for product quality and minimum energy consumption for microwave-convective drying of okra. PMID:24493879

  14. Preliminary verification of instantaneous air temperature estimation for clear sky conditions based on SEBAL

    NASA Astrophysics Data System (ADS)

    Zhu, Shanyou; Zhou, Chuxuan; Zhang, Guixin; Zhang, Hailong; Hua, Junwei

    2016-03-01

    Spatially distributed near surface air temperature at the height of 2 m is an important input parameter for the land surface models. It is of great significance in both theoretical research and practical applications to retrieve instantaneous air temperature data from remote sensing observations. An approach based on Surface Energy Balance Algorithm for Land (SEBAL) to retrieve air temperature under clear sky conditions is presented. Taking the meteorological measurement data at one station as the reference and remotely sensed data as the model input, the research estimates the air temperature by using an iterative computation. The method was applied to the area of Jiangsu province for nine scenes by using MODIS data products, as well as part of Fujian province, China based on four scenes of Landsat 8 imagery. Comparing the air temperature estimated from the proposed method with that of the meteorological station measurement, results show that the root mean square error is 1.7 and 2.6 °C at 1000 and 30 m spatial resolution respectively. Sensitivity analysis of influencing factors reveals that land surface temperature is the most sensitive to the estimation precision. Research results indicate that the method has great potentiality to be used to estimate instantaneous air temperature distribution under clear sky conditions.

  15. Prediction of air temperature in the aircraft cabin under different operational conditions

    NASA Astrophysics Data System (ADS)

    Volavý, F.; Fišer, J.; Nöske, I.

    2013-04-01

    This paper deals with the prediction of the air temperature in the aircraft cabin by means of Computational Fluid Dynamics. The simulations are performed on the CFD model which is based on geometry and cabin interior arrangement of the Flight Test Facility (FTF) located at Fraunhofer IBP, Germany. The experimental test flights under three different cabin temperatures were done in FTF and the various data were gathered during these flights. Air temperature in the cabin was measured on probes located near feet, torso and head of each passenger and also surface temperature and air temperature distributed from inlets were measured. The data were firstly analysed in order to obtain boundary conditions for cabin surfaces and inlets. Then the results of air temperature from the simulations were compared with measured data. The suitability and accuracy of the CFD approach for temperature prediction is discussed.

  16. Use of absorption refrigerating machines in mine air-conditioning systems

    SciTech Connect

    Duganov, G.V.; Rozhko, V.F.; Shtompel, A.I.; Timofeevskii, L.S.

    1984-07-01

    This article describes lithium bromide absorption refrigerating machines (LBARMs) designed for use in mine air-conditioning systems (MACS). The application of LBARMs in MACS is difficult due to the elevation of temperature of the cold carrier when supplied to the mine air refrigerants. A thermodynamic and thermoeconomic analysis was conducted to determine the principal lines of LBARM design for creating a suitable microclimate in underground mines. The MACS will maintain the temperature in the mines at a horizon of 913 m at 24-26/sup 0/C. A scheme is proposed for stage-by-stage cooling by connecting two machines in succession. It is concluded that the use of absorption refrigerating machines in coal mine air-conditioning systems facilitates the integrated and economic use of heat energy as well as of secondary heat resources for cold generation.

  17. [Study on air quality and pollution meteorology conditions of Guangzhou during the 2010 Asian games].

    PubMed

    Li, Ting-Yuan; Deng, Xue-Jiao; Fan, Shao-Jia; Wu, Dui; Li, Fei; Deng, Tao; Tan, Hao-Bo; Jiang, De-Hai

    2012-09-01

    Based on the monitoring data of NO2, O3, SO2, PM, visibility, regional air quality index (RAQI) and the atmospheric transport and diffusion data from Nov. 4, 2010 to Dec. 10, 2010 in Guangzhou area, the variations of air quality and meteorological conditions during the Guangzhou Asian Games were analyzed. It was found that, during the Asian Games, the air quality was better than the air quality before or after the Asian Games. The visibility was greater than the visibility before or after the Asian Games, while the concentrations of PM1 and PM2.5 were lower. The correlation coefficient between visibility and the concentrations of PM1, PM2.5 indicated anti-correlation relationships. Daily and hourly concentrations of NO2 and SO2 met the primary ambient air quality standards, whereas the daily concentration of PM10 and hourly concentration of O3 met the secondary ambient air quality standards. Pollutants had been well controlled during the Asian Games. The concentration of SO2 in Guangzhou was influenced by local sources and long distance transmission, while the concentration of NO2 was significantly influenced by local sources. The emissions of NO2, SO2 and PM10 surrounding Guangzhou had a trend to affect the concentrations in Guangzhou, but the situation of O3 was opposite, the relatively high concentration of O3 in Guangzhou had tendency to be transported to the surrounding areas. The pollution meteorology conditions in the period of Asian Games were better than the conditions before or after the Asian Games. The decrease in the concentrations during the Asian Games did not only benefit from the emission control by the government, but also from the good meteorological conditions.

  18. Introducing high-quality planar defects into colloidal crystals via self-assembly at the air/water interface

    NASA Astrophysics Data System (ADS)

    Zhong, Kuo; Demeyer, Pieter-Jan; Zhou, Xingping; Kruglova, Olga; Verellen, Niels; Moshchalkov, Victor V.; Song, Kai; Clays, Koen

    2015-02-01

    We demonstrate a facile method for fabrication of colloidal crystals containing a planar defect by using PS@SiO2 core-shell spheres as building blocks. A monolayer of solid spheres was embedded in core-shell colloidal crystals serving as the defect layer, which formed by means of self-assembly at the air/water interface. Compared with previous methods, this fabrication method results in pronounced passbands in the band gaps of the colloidal photonic crystal. The FWHM of the obtained passband is only ~16nm, which is narrower than the previously reported results. The influence of the defect layer thickness on the optical properties of these sandwiched structures was also investigated. No high-cost processes or specific equipment is needed in our approach. Inverse opals with planar defects can be obtained via calcination of the PS cores, without the need of infiltration. The experimental results are in good agreement with simulations performed using the FDTD method.

  19. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL... VEHICLES AND ENGINES General Compliance Provisions for Control of Air Pollution From New and In-Use Light...-01: (a)(1) Where it is expected that more than 33 percent of a car line, within a test group, will...

  20. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In... and 86.1828-01: (a)(1) Where it is expected that more than 33 percent of a car line, within a...

  1. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In... and 86.1828-01: (a)(1) Where it is expected that more than 33 percent of a car line, within a...

  2. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In... and 86.1828-01: (a)(1) Where it is expected that more than 33 percent of a car line, within a...

  3. Heating, Air Conditioning and Refrigeration Curriculum Guide. Michigan Trade and Industrial Education.

    ERIC Educational Resources Information Center

    Michigan State Univ., East Lansing. Coll. of Agriculture and Natural Resources Education Inst.

    This task-based curriculum guide for heating, air conditioning, and refrigeration is intended to help the teacher develop a classroom management system where students learn by doing. Introductory materials include a Dictionary of Occupational Titles job code and title sheet, a career ladder, a matrix relating duty/task numbers to job titles, and a…

  4. An Investigation of Energy Consumption and Cost in Large Air-Conditioned Buildings. An Interim Report.

    ERIC Educational Resources Information Center

    Milbank, N. O.

    Two similarly large buildings and air conditioning systems are comparatively analyzed as to energy consumption, costs, and inefficiency during certain measured periods of time. Building design and velocity systems are compared to heating, cooling, lighting and distribution capabilities. Energy requirements for pumps, fans and lighting are found to…

  5. Proceedings of the 1993 Non-Fluorocarbon Insulation, Refrigeration and Air Conditioning Technology Workshop

    NASA Astrophysics Data System (ADS)

    Sessions included: HFC blown polyurethanes, carbon dioxide blown foam and extruded polystyrenes, plastic foam insulations, evacuated panel insulation, refrigeration and air conditioning, absorption and adsorption and stirling cycle refrigeration, innovative cooling technologies, and natural refrigerants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  6. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... elements that are discussed are ambient air temperature and humidity, minimum test cell size, solar heating... be shown that all of the ambient test condition performance requirements are satisfied. (d) Solar heat loading. (1)(i) Acceptable types of radiant energy emitters that may be used for simulating...

  7. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... elements that are discussed are ambient air temperature and humidity, minimum test cell size, solar heating... be shown that all of the ambient test condition performance requirements are satisfied. (d) Solar heat loading. (1)(i) Acceptable types of radiant energy emitters that may be used for simulating...

  8. Design of a test facility for gas-fired desiccant-based air conditioning systems

    SciTech Connect

    Jalalzadeh-Azar, A.A.; Steele, W.G.; Hodge, B.K.

    1996-12-31

    The design of a facility for testing desiccant-based air conditioning systems is presented. The determination of the performance parameters of desiccant systems is discussed including moisture removal capacity, latent and total cooling capacities, and efficiency indexes. The appropriate procedures and key measurements for determining these parameters are identified using uncertainty analysis.

  9. Heating, Ventilation, Air Conditioning. Resource Manual for Custodial Training Course #3.

    ERIC Educational Resources Information Center

    Florida State Dept. of Education, Tallahassee. School Plant Management Section.

    Intended as a manual to provide school custodians with some understanding of basic functions of heating, ventilating, and air conditioning equipment for safe, efficient operation. Contains general rules and specifications for providing custodians with a more complete awareness of their equipment and the field of "Climate Control" within the…

  10. Geothermal as a heat sink application for raising air conditioning efficency

    NASA Astrophysics Data System (ADS)

    Ibrahim, Hesham Safwat Osman Mohamed

    2016-04-01

    Objective: Geothermal applications in heating, ventilation, air-conditioning is a US technology for more than 30 years old ,which saves more than 30% average energy cost than the traditional air-conditioning systems systems. Applying this technology in Middle East and African countries would be very feasible specially in Egypt specially as it suffers Electric crisis --The temperature of the condensers and the heat rejecting equipment is much higher than the Egyptian land at different depth which is a great advantages, and must be measured, recorded, and studied accurately -The Far goal of the proposal is to construct from soil analysis a temperature gradient map for Egypt and , African countries on different depth till 100 m which is still unclear nowadays and must be measured and recorded in databases through researches - The main model of the research is to study the heat transfer gradient through the ground earth borehole,grout,high density polyethylene pipes , and water inlet temperature which affect the electric efficiency of the ground source heat pump air conditioning unit Impact on the Region: Such research result will contribute widely in Energy saving sector specially the air conditioning sector in Egypt and the African countries which consumes more than 30% of the electric consumption of the total consumption . and encouraging Green systems such Geothermal to be applied

  11. Proceedings of the 1993 non-fluorocarbon insulation, refrigeration and air conditioning technology workshop

    SciTech Connect

    Not Available

    1994-09-01

    Sessions included: HFC blown polyurethanes, carbon dioxide blown foam and extruded polystyrenes, plastic foam insulations, evacuated panel insulation, refrigeration and air conditioning, absorption and adsorption and stirling cycle refrigeration, innovative cooling technologies, and natural refrigerants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  12. Military Curricula for Vocational & Technical Education. Refrigeration & Air Conditioning Specialist, Blocks I-II.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This plan of instruction, study guides, workbooks, and programmed texts for a secondary-postsecondary-level course in refrigeration and air conditioning are one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. It is the first section of a…

  13. Heating, Ventilation, Air-conditioning, and Refrigeration. Ohio's Competency Analysis Profile.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Vocational Instructional Materials Lab.

    Developed through a modified DACUM (Developing a Curriculum) process involving business, industry, labor, and community agency representatives in Ohio, this document is a comprehensive and verified employer competency profile for heating, ventilation, air conditioning, and refrigeration occupations. The list contains units (with and without…

  14. Principles of Refrigeration. Automotive Mechanics. Air Conditioning. Instructor's Guide [and] Student Guide.

    ERIC Educational Resources Information Center

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automobile air conditioning, consists of a student guide and an instructor guide dealing with the principles of refrigeration. Covered in the module are defining the term heat, defining the term British Thermal Unit (BTU), defining the term latent heat, listing…

  15. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... to simulate the impact of an ambient heat load on the power requirements of the vehicle's air conditioning compressor while operating on a specific driving cycle. The environmental facility control... heat load are: (A) Metal halide; (B) Quartz halogen with dichroic mirrors; and (C) Sodium iodide....

  16. Refrigeration and Air Conditioning Mechanic: Apprenticeship Course Outline. Apprenticeship and Industry Training. 1411.2

    ERIC Educational Resources Information Center

    Alberta Advanced Education and Technology, 2011

    2011-01-01

    The graduate of the Refrigeration and Air Conditioning Mechanic apprenticeship training is a journeyman who will: (1) supervise, train and coach apprentices; (2) use and maintain hand and power tools to the standards of competency and safety required in the trade; (3) have a thorough knowledge of the principle components of refrigeration systems,…

  17. Introduction to Heating, Ventilation and Air Conditioning (HVAC). Instructor Edition. Introduction to Construction Series.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This instructor's guide contains the materials required to teach a competency-based introductory course in heating, ventilating, and air conditioning (HVAC) to students who have chosen to explore careers in construction. It contains three units: HVAC materials, HVAC tools, and applied skills. Each instructional unit includes some or all of the…

  18. Introduction to Heating, Ventilation and Air Conditioning (HVAC). Introduction to Construction Series. Instructor Edition.

    ERIC Educational Resources Information Center

    Associated General Contractors of America, Washington, DC.

    This module on introductory heating, ventilating, and air conditioning (HVAC) is one of a series of modules designed to teach basic skills necessary for entry-level employment in this field. The module contains four instructional units that cover the following topics: (1) HVAC materials; (2) HVAC tools; (3) HVAC layout; and (4) HVAC basic skills.…

  19. Military Curricula for Vocational & Technical Education. Refrigeration and Air Conditioning Specialist, Blocks VI-IX.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This plan of instruction, study guides, and workbooks for a secondary-postsecondary-level course in refrigeration and air conditioning are one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. It is the third section of a three-part course (see…

  20. Technology evaluation of heating, ventilation, and air conditioning for MIUS application

    NASA Technical Reports Server (NTRS)

    Gill, W. L.; Keough, M. B.; Rippey, J. O.

    1974-01-01

    Potential ways of providing heating, ventilation, and air conditioning for a building complex serviced by a modular integrated utility system (MIUS) are examined. Literature surveys were conducted to investigate both conventional and unusual systems to serve this purpose. The advantages and disadvantages of the systems most compatible with MIUS are discussed.

  1. 76 FR 17487 - Protection of Stratospheric Ozone: New Substitute in the Motor Vehicle Air Conditioning Sector...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-29

    ... expanding the list of acceptable substitutes for use in the motor vehicle air conditioning end-use as a...-duty trucks. The substitute is a non-ozone-depleting gas and consequently does not contribute to... Order FMEA--Failure Mode and Effect Analysis FR--Federal Register GWP--Global Warming Potential...

  2. The Evaluation of Unitary & Central Type Air-Conditioning Systems in Selected Florida Schools.

    ERIC Educational Resources Information Center

    Bradley, William B.

    The study reported here was conducted in an effort to obtain data for comparing the combined owning and operating costs of two different types of air-conditioning systems in two elementary schools. Both schools were built during 1969-70 in the same geographical area along the southeast coast of Florida and are also served by the same electric…

  3. Heating, Air Conditioning and Refrigeration. Vocational Education Curriculum Guide. Industrial and Technical Education.

    ERIC Educational Resources Information Center

    West Virginia State Vocational Curriculum Lab., Cedar Lakes.

    This curriculum guide contains 17 units that provides the basic curriculum components required to develop lesson plans for the heating, air conditioning, and refrigeration curriculum. The guide is not intended to be a complete, self-contained curriculum, but instead provides the teacher with a number of informational items related to the learning…

  4. Instructional Guide for Air Conditioning and Refrigeration. V & TECC Curriculum Guide.

    ERIC Educational Resources Information Center

    Duenk, Lester G.; And Others

    This trade and industrial curriculum guide is intended for use in vocational programs that prepare students to enter the air conditioning/refrigeration field. The introductory section provides a statement of philosophy, objectives, block time schedule, and recommended facilities and equipment. Following the introductory section, eighteen blocks of…

  5. Environmental Control System Installer/Servicer (Residential Air Conditioning Mechanic). V-TECS Guide.

    ERIC Educational Resources Information Center

    Meyer, Calvin F.; Benson, Robert T.

    This guide provides job relevant tasks, performance objectives, performance guides, resources, learning activitites, evaluation standards, and achievement testing in the occupation of environmental control system installer/servicer (residential air conditioning mechanic). It is designed to be used with any chosen teaching method. The course…

  6. Non-Print Instructional Materials for the Air Conditioning and Refrigeration Maintenance Field.

    ERIC Educational Resources Information Center

    Golitko, Raymond L., Ed.; And Others

    This catalog contains a listing of air conditioning/refrigeration maintenance audiovisual training materials from the Houston Community College System library media collection. The material is organized by subject heading. The media titles are listed in alphabetical order by title under each subject heading in the catalog. The citation for each…

  7. Refrigeration and Air Conditioning Equipment, 11-9. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This military-developed text consists of three blocks of instructional materials for use by those studying to become refrigeration and air conditioning specialists. Covered in the individual course blocks are the following topics: refrigeration and trouble analysis, thermodynamics, and principles of refrigeration; major components and domestic and…

  8. Getting Down to Business: Air Conditioning and Heating Service, Module 36. [Student Guide]. Entrepreneurship Training Components.

    ERIC Educational Resources Information Center

    Sanderson, Barbara

    This module on owning and operating an air conditioning and heating service is one of 36 in a series on entrepreneurship. The introduction tells the student what topics will be covered and suggests other modules to read in related occupations. Each unit includes student goals, a case study, and a discussion of the unit subject matter. Learning…

  9. 10 CFR 71.74 - Accident conditions for air transport of plutonium.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Accident conditions for air transport of plutonium. 71.74 Section 71.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE... plutonium. (a) Test conditions—Sequence of tests. A package must be physically tested to the...

  10. VESL for Heating and Air Conditioning: A Competency-based Curriculum Guide. Project OSCAER.

    ERIC Educational Resources Information Center

    Lopez-Valadez, Jeanne, Ed.; Pankratz, David, Ed.

    This guide is intended for vocational educators developing the vocational English as a second language (VESL) component of a course in heating and air conditioning. The introductory section examines assumptions about second language learning and instruction and VESL classes, local adaptations of the curriculum, and sample VESL lessons. The chapter…

  11. Urban air quality assessment using monitoring data of fractionized aerosol samples, chemometrics and meteorological conditions.

    PubMed

    Yotova, Galina I; Tsitouridou, Roxani; Tsakovski, Stefan L; Simeonov, Vasil D

    2016-01-01

    The present article deals with assessment of urban air by using monitoring data for 10 different aerosol fractions (0.015-16 μm) collected at a typical urban site in City of Thessaloniki, Greece. The data set was subject to multivariate statistical analysis (cluster analysis and principal components analysis) and, additionally, to HYSPLIT back trajectory modeling in order to assess in a better way the impact of the weather conditions on the pollution sources identified. A specific element of the study is the effort to clarify the role of outliers in the data set. The reason for the appearance of outliers is strongly related to the atmospheric condition on the particular sampling days leading to enhanced concentration of pollutants (secondary emissions, sea sprays, road and soil dust, combustion processes) especially for ultra fine and coarse particles. It is also shown that three major sources affect the urban air quality of the location studied-sea sprays, mineral dust and anthropogenic influences (agricultural activity, combustion processes, and industrial sources). The level of impact is related to certain extent to the aerosol fraction size. The assessment of the meteorological conditions leads to defining of four downwind patterns affecting the air quality (Pelagic, Western and Central Europe, Eastern and Northeastern Europe and Africa and Southern Europe). Thus, the present study offers a complete urban air assessment taking into account the weather conditions, pollution sources and aerosol fractioning.

  12. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... elements that are discussed are ambient air temperature and humidity, minimum test cell size, solar heating... be shown that all of the ambient test condition performance requirements are satisfied. (d) Solar heat loading. (1)(i) Acceptable types of radiant energy emitters that may be used for simulating...

  13. Statistical modeling of urban air temperature distributions under different synoptic conditions

    NASA Astrophysics Data System (ADS)

    Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Hald, Cornelius; Hartz, Uwe; Jacobeit, Jucundus; Richter, Katja; Schneider, Alexandra; Wolf, Kathrin

    2015-04-01

    Within urban areas air temperature may vary distinctly between different locations. These intra-urban air temperature variations partly reach magnitudes that are relevant with respect to human thermal comfort. Therefore and furthermore taking into account potential interrelations with other health related environmental factors (e.g. air quality) it is important to estimate spatial patterns of intra-urban air temperature distributions that may be incorporated into urban planning processes. In this contribution we present an approach to estimate spatial temperature distributions in the urban area of Augsburg (Germany) by means of statistical modeling. At 36 locations in the urban area of Augsburg air temperatures are measured with high temporal resolution (4 min.) since December 2012. These 36 locations represent different typical urban land use characteristics in terms of varying percentage coverages of different land cover categories (e.g. impervious, built-up, vegetated). Percentage coverages of these land cover categories have been extracted from different sources (Open Street Map, European Urban Atlas, Urban Morphological Zones) for regular grids of varying size (50, 100, 200 meter horizonal resolution) for the urban area of Augsburg. It is well known from numerous studies that land use characteristics have a distinct influence on air temperature and as well other climatic variables at a certain location. Therefore air temperatures at the 36 locations are modeled utilizing land use characteristics (percentage coverages of land cover categories) as predictor variables in Stepwise Multiple Regression models and in Random Forest based model approaches. After model evaluation via cross-validation appropriate statistical models are applied to gridded land use data to derive spatial urban air temperature distributions. Varying models are tested and applied for different seasons and times of the day and also for different synoptic conditions (e.g. clear and calm

  14. Performance and evaluation of gas engine driven rooftop air conditioning equipment at the Willow Grove (PA) Naval Air Station

    SciTech Connect

    Armstrong, P.R.; Conover, D.R.

    1993-05-01

    In a field evaluation conducted for the US Department of Energy (DOE) Office of Federal Energy Management Program (FEMP), the Pacific Northwest Laboratory (PNL) examined the performance of a new US energy-related technology under the FEMP Test Bed Demonstration Program. The technology was a 15-ton natural gas engine driven roof top air conditioning unit. Two such units were installed on a naval retail building to provide space conditioning to the building. Under the Test Bed Demonstration Program, private and public sector interests are focused to support the installation and evaluation of new US technologies in the federal sector. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) with DOE were the American Gas Cooling Center, Philadelphia Electric Company, Thermo King Corporation, and the US Naval Air Station at Willow Grove, Pennsylvania. Equipment operating and service data as well as building interior and exterior conditions were secured for the 1992 cooling season. Based on a computer assessment of the building using standard weather data, a comparison was made with the energy and operating costs associated with the previous space conditioning system. Based on performance during the 1992 cooling season and adjusted to a normal weather year, the technology will save the site $6,000/yr in purchased energy costs. An additional $9,000 in savings due to electricity demand ratchet charge reductions will also be realized. Detailed information on the technology, the installation, and the results of the technology test are provided to illustrate the advantages to the federal sector of using this technology. A history of the CRADA development process is also reported.

  15. Waking the sleeping giant: Introducing new heat exchanger technology into the residential air-conditioning marketplace

    SciTech Connect

    Chapp, T.; Voss, M.; Stephens, C.

    1998-07-01

    The Air Conditioning Industry has made tremendous strides in improvements to the energy efficiency and reliability of its product offerings over the past 40 years. These improvement can be attributed to enhancements of components, optimization of the energy cycle, and modernized and refined manufacturing techniques. During this same period, energy consumption for space cooling has grown significantly. In January of 1992, the minimum efficiency requirement for central air conditioning equipment was raised to 10 SEER. This efficiency level is likely to increase further under the auspices of the National Appliance Energy Conservation Act (NAECA). A new type of heat exchanger was developed for air conditioning equipment by Modine Manufacturing Company in the early 1990's. Despite significant advantages in terms of energy efficiency, dehumidification, durability, and refrigerant charge there has been little interest expressed by the air conditioning industry. A cooperative effort between Modine, various utilities, and several state energy offices has been organized to test and demonstrate the viability of this heat exchanger design throughout the nation. This paper will review the fundamentals of heat exchanger design and document this simple, yet novel technology. These experiences involving equipment retrofits have been documented with respect to the performance potential of air conditioning system constructed with PF{trademark} Heat Exchangers (generically referred to as microchannel heat exchangers) from both an energy efficiency as well as a comfort perspective. The paper will also detail the current plan to introduce 16 to 24 systems into an extended field test throughout the US which commenced in the Fall of 1997.

  16. Total environmental warming impact (TEWI) calculations for alternative automative air-conditioning systems

    SciTech Connect

    Sand, J.R.; Fischer, S.K.

    1997-01-01

    The Montreal Protocol phase-out of chlorofluorocarbons (CFCs) has required manufacturers to develop refrigeration and air-conditioning systems that use refrigerants that can not damage stratospheric ozone. Most refrigeration industries have adapted their designs to use hydrochlorofluorocarbon (HCFC) or hydrofluorocarbon (HFC) refrigerants; new automobile air- conditioning systems use HFC-134a. These industries are now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants on global warming. Automobile air-conditioning has three separate impacts on global warming; (1) the effects of refrigerant inadvertently released to the atmosphere from accidents, servicing, and leakage; (2) the efficiency of the cooling equipment (due to the emission of C0{sub 2} from burning fuel to power the system); and (3) the emission of C0{sub 2} from burning fuel to transport the system. The Total Equivalent Warming Impact (TEWI) is an index that should be used to compare the global warming effects of alternative air-conditioning systems because it includes these contributions from the refrigerant, cooling efficiency, and weight. This paper compares the TEWI of current air-conditioning systems using HFC-134a with that of transcritical vapor compression system using carbon dioxide and systems using flammable refrigerants with secondary heat transfer loops. Results are found to depend on both climate and projected efficiency of C0{sub 2}systems. Performance data on manufacturing prototype systems are needed to verify the potential reductions in TEWI. Extensive field testing is also required to determine the performance, reliability, and ``serviceability`` of each alternative to HFC-134a to establish whether the potential reduction of TEWI can be achieved in a viable consumer product.

  17. Influence of indoor air conditions on radon concentration in a detached house.

    PubMed

    Akbari, Keramatollah; Mahmoudi, Jafar; Ghanbari, Mahdi

    2013-02-01

    Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cancer. Indoor air conditions and ventilation systems strongly influence indoor radon concentrations. This paper focuses on effects of air change rate, indoor temperature and relative humidity on indoor radon concentrations in a one family detached house in Stockholm, Sweden. In this study a heat recovery ventilation system unit was used to control the ventilation rate and a continuous radon monitor (CRM) was used to measure radon levels. FLUENT, a computational fluid dynamics (CFD) software package was used to simulate radon entry into the building and air change rate, indoor temperature and relative humidity effects using a numerical approach. The results from analytical solution, measurements and numerical simulations showed that air change rate, indoor temperature and moisture had significant effects on indoor radon concentration. Increasing air change rate reduces radon level and for a specific air change rate (in this work Ach = 0.5) there was a range of temperature and relative humidity that minimized radon levels. In this case study minimum radon levels were obtained at temperatures between 20 and 22 °C and a relative humidity of 50-60%.

  18. Influence of indoor air conditions on radon concentration in a detached house.

    PubMed

    Akbari, Keramatollah; Mahmoudi, Jafar; Ghanbari, Mahdi

    2013-02-01

    Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cancer. Indoor air conditions and ventilation systems strongly influence indoor radon concentrations. This paper focuses on effects of air change rate, indoor temperature and relative humidity on indoor radon concentrations in a one family detached house in Stockholm, Sweden. In this study a heat recovery ventilation system unit was used to control the ventilation rate and a continuous radon monitor (CRM) was used to measure radon levels. FLUENT, a computational fluid dynamics (CFD) software package was used to simulate radon entry into the building and air change rate, indoor temperature and relative humidity effects using a numerical approach. The results from analytical solution, measurements and numerical simulations showed that air change rate, indoor temperature and moisture had significant effects on indoor radon concentration. Increasing air change rate reduces radon level and for a specific air change rate (in this work Ach = 0.5) there was a range of temperature and relative humidity that minimized radon levels. In this case study minimum radon levels were obtained at temperatures between 20 and 22 °C and a relative humidity of 50-60%. PMID:23159846

  19. Effect of Intake Air Filter Condition on Light-Duty Gasoline Vehicles

    SciTech Connect

    Thomas, John F; Huff, Shean P; West, Brian H; Norman, Kevin M

    2012-01-01

    Proper maintenance can help vehicles perform as designed, positively affecting fuel economy, emissions, and the overall drivability. This effort investigates the effect of one maintenance factor, intake air filter replacement, with primary focus on vehicle fuel economy, but also examining emissions and performance. Older studies, dealing with carbureted gasoline vehicles, have indicated that replacing a clogged or dirty air filter can improve vehicle fuel economy and conversely that a dirty air filter can be significantly detrimental to fuel economy. The effect of clogged air filters on the fuel economy, acceleration and emissions of five gasoline fueled vehicles is examined. Four of these were modern vehicles, featuring closed-loop control and ranging in model year from 2003 to 2007. Three vehicles were powered by naturally aspirated, port fuel injection (PFI) engines of differing size and cylinder configuration: an inline 4, a V6 and a V8. A turbocharged inline 4-cylinder gasoline direct injection (GDI) engine powered vehicle was the fourth modern gasoline vehicle tested. A vintage 1972 vehicle equipped with a carburetor (open-loop control) was also examined. Results reveal insignificant fuel economy and emissions sensitivity of modern vehicles to air filter condition, but measureable effects on the 1972 vehicle. All vehicles experienced a measured acceleration performance penalty with clogged intake air filters.

  20. Solar Absorption Refrigeration System for Air-Conditioning of a Classroom Building in Northern India

    NASA Astrophysics Data System (ADS)

    Agrawal, Tanmay; Varun; Kumar, Anoop

    2015-10-01

    Air-conditioning is a basic tool to provide human thermal comfort in a building space. The primary aim of the present work is to design an air-conditioning system based on vapour absorption cycle that utilizes a renewable energy source for its operation. The building under consideration is a classroom of dimensions 18.5 m × 13 m × 4.5 m located in Hamirpur district of Himachal Pradesh in India. For this purpose, cooling load of the building was calculated first by using cooling load temperature difference method to estimate cooling capacity of the air-conditioning system. Coefficient of performance of the refrigeration system was computed for various values of strong and weak solution concentration. In this work, a solar collector is also designed to provide required amount of heat energy by the absorption system. This heat energy is taken from solar energy which makes this system eco-friendly and sustainable. A computer program was written in MATLAB to calculate the design parameters. Results were obtained for various values of solution concentrations throughout the year. Cost analysis has also been carried out to compare absorption refrigeration system with conventional vapour compression cycle based air-conditioners.

  1. Talaromyces rubrifaciens, a new species discovered from heating, ventilation and air conditioning systems in China.

    PubMed

    Luo, Yi; Lu, Xiaohong; Bi, Wu; Liu, Fan; Gao, Weiwei

    2016-01-01

    A new Talaromyces species, T. rubrifaciens, was isolated from supply air outlets of heating, ventilation and air conditioning (HVAC) systems in three kinds of public building in Beijing and Nanjing, China. Morphologically it exhibits many characters of section Trachyspermi but is distinguished from other species of this section by restricted growth and broad and strictly biverticillate conidiophores. Phylogenetic analyses based on the internal transcribed spacer rDNA (ITS), β-tubulin (BenA), calmodulin (CaM) and RNA polymerase second largest subunit (RPB2) genes reveal that T. rubrifaciens is a distinct species in section Trachyspermi. PMID:27055570

  2. Talaromyces rubrifaciens, a new species discovered from heating, ventilation and air conditioning systems in China.

    PubMed

    Luo, Yi; Lu, Xiaohong; Bi, Wu; Liu, Fan; Gao, Weiwei

    2016-01-01

    A new Talaromyces species, T. rubrifaciens, was isolated from supply air outlets of heating, ventilation and air conditioning (HVAC) systems in three kinds of public building in Beijing and Nanjing, China. Morphologically it exhibits many characters of section Trachyspermi but is distinguished from other species of this section by restricted growth and broad and strictly biverticillate conidiophores. Phylogenetic analyses based on the internal transcribed spacer rDNA (ITS), β-tubulin (BenA), calmodulin (CaM) and RNA polymerase second largest subunit (RPB2) genes reveal that T. rubrifaciens is a distinct species in section Trachyspermi.

  3. Fault tree analysis for exposure to refrigerants used for automotive air conditioning in the United States.

    PubMed

    Jetter, J J; Forte, R; Rubenstein, R

    2001-02-01

    A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servicing. The number of refrigerant exposures of service technicians was estimated to be 135,000 per year. Exposures of vehicle occupants can occur when refrigerant enters passenger compartments due to sudden leaks in air-conditioning systems, leaks following servicing, or leaks caused by collisions. The total number of exposures of vehicle occupants was estimated to be 3,600 per year. The largest number of exposures of vehicle occupants was estimated for leaks caused by collisions, and the second largest number of exposures was estimated for leaks following servicing. Estimates used in the fault tree analysis were based on a survey of automotive air-conditioning service shops, the best available data from the literature, and the engineering judgement of the authors and expert reviewers from the Society of Automotive Engineers Interior Climate Control Standards Committee. Exposure concentrations and durations were estimated and compared with toxicity data for refrigerants currently used in automotive air conditioners. Uncertainty was high for the estimated numbers of exposures, exposure concentrations, and exposure durations. Uncertainty could be reduced in the future by conducting more extensive surveys, measurements of refrigerant concentrations, and exposure monitoring. Nevertheless, the analysis indicated that the risk of exposure of service technicians and vehicle occupants is significant, and it is recommended that no refrigerant that is substantially more toxic than currently available substitutes be accepted for use in vehicle air-conditioning systems, absent a means of mitigating exposure. PMID:11332544

  4. Fault tree analysis for exposure to refrigerants used for automotive air conditioning in the United States.

    PubMed

    Jetter, J J; Forte, R; Rubenstein, R

    2001-02-01

    A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servicing. The number of refrigerant exposures of service technicians was estimated to be 135,000 per year. Exposures of vehicle occupants can occur when refrigerant enters passenger compartments due to sudden leaks in air-conditioning systems, leaks following servicing, or leaks caused by collisions. The total number of exposures of vehicle occupants was estimated to be 3,600 per year. The largest number of exposures of vehicle occupants was estimated for leaks caused by collisions, and the second largest number of exposures was estimated for leaks following servicing. Estimates used in the fault tree analysis were based on a survey of automotive air-conditioning service shops, the best available data from the literature, and the engineering judgement of the authors and expert reviewers from the Society of Automotive Engineers Interior Climate Control Standards Committee. Exposure concentrations and durations were estimated and compared with toxicity data for refrigerants currently used in automotive air conditioners. Uncertainty was high for the estimated numbers of exposures, exposure concentrations, and exposure durations. Uncertainty could be reduced in the future by conducting more extensive surveys, measurements of refrigerant concentrations, and exposure monitoring. Nevertheless, the analysis indicated that the risk of exposure of service technicians and vehicle occupants is significant, and it is recommended that no refrigerant that is substantially more toxic than currently available substitutes be accepted for use in vehicle air-conditioning systems, absent a means of mitigating exposure.

  5. Self-assembled and highly selective sensors based on air-bridge-structured nanowire junction arrays.

    PubMed

    Park, Won Jeong; Choi, Kyung Jin; Kim, Myung Hwa; Koo, Bon Hyeong; Lee, Jong-Lam; Baik, Jeong Min

    2013-08-14

    We describe a strategy for creating an air-bridge-structured nanowire junction array platform that capable of reliably discriminating between three gases (hydrogen, carbon monoxide, and nitrogen dioxide) in air. Alternatively driven dual nanowire species of ZnO and CuO with the average diameter of ∼30 nm on a single substrate are used and decorated with metallic nanoparticles to form two-dimensional microarray, which do not need to consider the post fabrications. Each individual nanowires in the array form n-n, p-p, and p-n junctions at the micro/nanoscale on single substrate and the junctions act as electrical conducting path for carriers. The adsorption of gas molecules to the surface changes the potential barrier height formed at the junctions and the carrier transport inside the straight semiconductors, which provide the ability of a given sensor array to differentiate among the junctions. The sensors were tested for their ability to distinguish three gases (H2, CO, and NO2), which they were able to do unequivocally when the data was classified using linear discriminant analysis. PMID:23841667

  6. Characteristics of Water Vapor Under Partially Cloudy Conditions: Observations by the Atmospheric Infrared Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    Fishbein, E.

    2003-12-01

    The variability and quality of tropical water vapor derived from the Atmospheric Infrared Sounder (AIRS) are characterized. Profiles of water vapor, temperature and surface characteristics (states) are derived from coincident Advance Microwave Sounding Unit (AMSU) and 3x3 sets of AIRS footprints. States are obtained under partially cloudy conditions by estimating the radiances emitted from the clear portions of the AIRS footprints. This procedure, referred to as cloud clearing, amplifies the measurement noise, and the amplification increases with cloud amount and uniformity. Cumulus and stratus cloud amount are related to the water vapor saturation, and noise amplification and water vapor amount may be partially correlated. The correlations between the uncertainty of retrieved water vapor, cloudiness and noise amplification are characterized. Retrieved water vapor is generally good when the amplification is less than three. Water vapor profiles are compared with correlative data, such as radiosondes and numerical weather center analyses and are in relatively good agreement in the lower troposphere

  7. Air Pollution modifies the association between successful and pathological aging throughout the frailty condition.

    PubMed

    Fougère, Bertrand; Vellas, Bruno; Billet, Sylvain; Martin, Perrine J; Gallucci, Maurizio; Cesari, Matteo

    2015-11-01

    The rapid growth in the number of older adults has many implications for public health, including the need to better understand the risks posed by environmental exposures. Aging leads to a decline and deterioration of functional properties at the cellular, tissue and organ level. This loss of functional properties yields to a loss of homeostasis and decreased adaptability to internal and external stress. Frailty is a geriatric syndrome characterized by weakness, weight loss, and low activity that is associated with adverse health outcomes. Frailty manifests as an age-related, biological vulnerability to stressors and decreased physiological reserves. Ambient air pollution exposure affects human health, and elderly people appear to be particularly susceptible to its adverse effects. The aim of this paper is to discuss the role of air pollution in the modulation of several biological mechanisms involved in aging. Evidence is presented on how air pollution can modify the bidirectional association between successful and pathological aging throughout the frailty conditions.

  8. 14 CFR 105.21 - Parachute operations over or into a congested area or an open-air assembly of persons.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Parachute operations over or into a... PARACHUTE OPERATIONS Operating Rules § 105.21 Parachute operations over or into a congested area or an open-air assembly of persons. (a) No person may conduct a parachute operation, and no pilot in command...

  9. 14 CFR 105.21 - Parachute operations over or into a congested area or an open-air assembly of persons.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Parachute operations over or into a... PARACHUTE OPERATIONS Operating Rules § 105.21 Parachute operations over or into a congested area or an open-air assembly of persons. (a) No person may conduct a parachute operation, and no pilot in command...

  10. 14 CFR 105.21 - Parachute operations over or into a congested area or an open-air assembly of persons.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Parachute operations over or into a... PARACHUTE OPERATIONS Operating Rules § 105.21 Parachute operations over or into a congested area or an open-air assembly of persons. (a) No person may conduct a parachute operation, and no pilot in command...

  11. 14 CFR 105.21 - Parachute operations over or into a congested area or an open-air assembly of persons.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Parachute operations over or into a... PARACHUTE OPERATIONS Operating Rules § 105.21 Parachute operations over or into a congested area or an open-air assembly of persons. (a) No person may conduct a parachute operation, and no pilot in command...

  12. 14 CFR 105.21 - Parachute operations over or into a congested area or an open-air assembly of persons.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Parachute operations over or into a... PARACHUTE OPERATIONS Operating Rules § 105.21 Parachute operations over or into a congested area or an open-air assembly of persons. (a) No person may conduct a parachute operation, and no pilot in command...

  13. Conditional Knockout of Tumor Overexpressed Gene in Mouse Neurons Affects RNA Granule Assembly, Granule Translation, LTP and Short Term Habituation

    PubMed Central

    Barbarese, Elisa; Ifrim, Marius F.; Hsieh, Lawrence; Guo, Caiying; Tatavarty, Vedakumar; Maggipinto, Michael J.; Korza, George; Tutolo, Jessica W.; Giampetruzzi, Anthony; Le, Hien; Ma, Xin-Ming; Levine, Eric; Bishop, Brian; Kim, Duck O.; Kuwada, Shigeyuki; Carson, John H.

    2013-01-01

    In neurons, specific RNAs are assembled into granules, which are translated in dendrites, however the functional consequences of granule assembly are not known. Tumor overexpressed gene (TOG) is a granule-associated protein containing multiple binding sites for heterogeneous nuclear ribonucleoprotein (hnRNP) A2, another granule component that recognizes cis-acting sequences called hnRNP A2 response elements (A2REs) present in several granule RNAs. Translation in granules is sporadic, which is believed to reflect monosomal translation, with occasional bursts, which are believed to reflect polysomal translation. In this study, TOG expression was conditionally knocked out (TOG cKO) in mouse hippocampal neurons using cre/lox technology. In TOG cKO cultured neurons granule assembly and bursty translation of activity-regulated cytoskeletal associated (ARC) mRNA, an A2RE RNA, are disrupted. In TOG cKO brain slices synaptic sensitivity and long term potentiation (LTP) are reduced. TOG cKO mice exhibit hyperactivity, perseveration and impaired short term habituation. These results suggest that in hippocampal neurons TOG is required for granule assembly, granule translation and synaptic plasticity, and affects behavior. PMID:23936366

  14. Maximum mixing times of methane and air under non-reacting and reacting conditions

    SciTech Connect

    Brasoveanu, D.; Gupta, A.K.

    1998-07-01

    Mixing times between methane and air under non-reacting or reacting conditions in the presence of rates of temperature and pressure and velocity gradients are examined using a mixing model based on the ideal gas law and the equation of continuity. The model is valid for low pressure combustors under non-reacting conditions. The model is also valid under reacting conditions for the fresh mixture which contains only trace amounts of combustion products. The effects of initial pressure, temperature and fluid composition on mixing time are also analyzed. In general, the exact mixing time has to be determined numerically. Nevertheless maximum values of mixing times can be determined analytically for a broad range of operational conditions. Results show that under both reacting and non-reacting conditions, the maximum mixing time is directly proportional to the initial pressure and temperature of mixture and inversely proportional to rates of pressure and temperature, and to velocity divergence. Mixing through fuel dispersion into the surrounding air is shown to be faster than via air penetration into the fuel flow. Rates of pressure of less than 1 atm/s acting along provide a mixing time in excess of one second which is unacceptably long for many applications, in particular gas turbine combustion. Rates of temperature produced by flame may provide mixing times shorter than 0.1 s. Mixing times of the order of a few milliseconds for efficient combustion and low emission, require high velocity gradients at the fuel-air boundary. Results show that enhanced mixing is achieved by combining temperature and velocity gradients. This analysis of mixing time is intended to provide important design guidelines for the development of high intensity, high efficiency and low emission combustors.

  15. Children's well-being at schools: Impact of climatic conditions and air pollution.

    PubMed

    Salthammer, Tunga; Uhde, Erik; Schripp, Tobias; Schieweck, Alexandra; Morawska, Lidia; Mazaheri, Mandana; Clifford, Sam; He, Congrong; Buonanno, Giorgio; Querol, Xavier; Viana, Mar; Kumar, Prashant

    2016-09-01

    Human civilization is currently facing two particular challenges: population growth with a strong trend towards urbanization and climate change. The latter is now no longer seriously questioned. The primary concern is to limit anthropogenic climate change and to adapt our societies to its effects. Schools are a key part of the structure of our societies. If future generations are to take control of the manifold global problems, we have to offer our children the best possible infrastructure for their education: not only in terms of the didactic concepts, but also with regard to the climatic conditions in the school environment. Between the ages of 6 and 19, children spend up to 8h a day in classrooms. The conditions are, however, often inacceptable and regardless of the geographic situation, all the current studies report similar problems: classrooms being too small for the high number of school children, poor ventilation concepts, considerable outdoor air pollution and strong sources of indoor air pollution. There have been discussions about a beneficial and healthy air quality in classrooms for many years now and in recent years extensive studies have been carried out worldwide. The problems have been clearly outlined on a scientific level and there are prudent and feasible concepts to improve the situation. The growing number of publications also highlights the importance of this subject. High carbon dioxide concentrations in classrooms, which indicate poor ventilation conditions, and the increasing particle matter in urban outdoor air have, in particular, been identified as primary causes of poor indoor air quality in schools. Despite this, the conditions in most schools continue to be in need of improvement. There are many reasons for this. In some cases, the local administrative bodies do not have the budgets required to address such concerns, in other cases regulations and laws stand in contradiction to the demands for better indoor air quality, and sometimes

  16. Children's well-being at schools: Impact of climatic conditions and air pollution.

    PubMed

    Salthammer, Tunga; Uhde, Erik; Schripp, Tobias; Schieweck, Alexandra; Morawska, Lidia; Mazaheri, Mandana; Clifford, Sam; He, Congrong; Buonanno, Giorgio; Querol, Xavier; Viana, Mar; Kumar, Prashant

    2016-09-01

    Human civilization is currently facing two particular challenges: population growth with a strong trend towards urbanization and climate change. The latter is now no longer seriously questioned. The primary concern is to limit anthropogenic climate change and to adapt our societies to its effects. Schools are a key part of the structure of our societies. If future generations are to take control of the manifold global problems, we have to offer our children the best possible infrastructure for their education: not only in terms of the didactic concepts, but also with regard to the climatic conditions in the school environment. Between the ages of 6 and 19, children spend up to 8h a day in classrooms. The conditions are, however, often inacceptable and regardless of the geographic situation, all the current studies report similar problems: classrooms being too small for the high number of school children, poor ventilation concepts, considerable outdoor air pollution and strong sources of indoor air pollution. There have been discussions about a beneficial and healthy air quality in classrooms for many years now and in recent years extensive studies have been carried out worldwide. The problems have been clearly outlined on a scientific level and there are prudent and feasible concepts to improve the situation. The growing number of publications also highlights the importance of this subject. High carbon dioxide concentrations in classrooms, which indicate poor ventilation conditions, and the increasing particle matter in urban outdoor air have, in particular, been identified as primary causes of poor indoor air quality in schools. Despite this, the conditions in most schools continue to be in need of improvement. There are many reasons for this. In some cases, the local administrative bodies do not have the budgets required to address such concerns, in other cases regulations and laws stand in contradiction to the demands for better indoor air quality, and sometimes

  17. Low-Flow Liquid Desiccant Air-Conditioning: Demonstrated Performance and Cost Implications

    SciTech Connect

    Kozubal, E.; Herrmann, L.; Deru, M.; Clark, J.; Lowenstein, A.

    2014-09-01

    Cooling loads must be dramatically reduced when designing net-zero energy buildings or other highly efficient facilities. Advances in this area have focused primarily on reducing a building's sensible cooling loads by improving the envelope, integrating properly sized daylighting systems, adding exterior solar shading devices, and reducing internal heat gains. As sensible loads decrease, however, latent loads remain relatively constant, and thus become a greater fraction of the overall cooling requirement in highly efficient building designs, particularly in humid climates. This shift toward latent cooling is a challenge for heating, ventilation, and air-conditioning (HVAC) systems. Traditional systems typically dehumidify by first overcooling air below the dew-point temperature and then reheating it to an appropriate supply temperature, which requires an excessive amount of energy. Another dehumidification strategy incorporates solid desiccant rotors that remove water from air more efficiently; however, these systems are large and increase fan energy consumption due to the increased airside pressure drop of solid desiccant rotors. A third dehumidification strategy involves high flow liquid desiccant systems. These systems require a high maintenance separator to protect the air distribution system from corrosive desiccant droplet carryover and so are more commonly used in industrial applications and rarely in commercial buildings. Both solid desiccant systems and most high-flow liquid desiccant systems (if not internally cooled) add sensible energy which must later be removed to the air stream during dehumidification, through the release of sensible heat during the sorption process.

  18. [The main ways of improvement of medical support of the Air Forces in modern conditions].

    PubMed

    Blaginin, A A; Grebeniuk, A N; Lizogub, I N

    2014-02-01

    Blaginin A.A., Grebenyuk A.N., Lizogub LN. - The main ways of improvement of medical support of the Air Forces in modern conditions. Aircrew conducting active hostilities suffers from the whole spectrum of factors and conditions of the combat situation. The main task for the medical service of the Air Force is to carry out preventive and curative action for aviation specialists who are responsible for the combat capability of aircraft formations. The medical service of the Air Force must have forces and facilities for planning, organization and implementation of the treatment of lightly wounded and sick aviation professionals with short periods of recovery, medical rehabilitation of aircrew qfter suffering injuries, diseases, sanatorium therapy of aircrew with partial failure of health, outpatient and inpatient medical examination aircrew - flight commissions, preventive rest of aviation specialists with symptoms of chronic fatigue. Should be trained aviation physicians, including both basic military medical education and in-depth study of the medical aspects of various fields of personnel of the Air Force. PMID:25046924

  19. Effect of green roofs on air temperature; measurement study of well-watered and dry conditions

    NASA Astrophysics Data System (ADS)

    Solcerova, Anna; van de Ven, Frans; Wang, Mengyu; van de Giesen, Nick

    2016-04-01

    Rapid urbanization and increasing number and duration of heat waves poses a need for understanding urban climate and ways to mitigate extremely high temperatures. One of repeatedly suggested and often investigated methods to moderate the so called urban heat island are green roofs. This study investigates several extensive green roofs in Utrecht (NL) and their effect on air temperature right above the roof surface. Air temperature was measured 15 and 30 cm above the roof surface and also in the substrate. We show that under normal condition is air above green roof, compared to white gravel roof, colder at night and warmer during day. This suggest that green roofs might help decrease air temperatures at night, when the urban heat island is strongest, but possibly contribute to high temperatures during daytime. We also measured situation when the green roofs wilted and dried out. Under such conditions green roof exhibits more similar behavior to conventional white gravel roof. Interestingly, pattern of soil temperature remains almost the same for both dry and well-prospering green roof, colder during day and warmer at night. As such, green roof works as a buffer of diurnal temperature changes.

  20. Air conditioning impact on the dynamics of radon and its daughters concentration.

    PubMed

    Kozak, Krzysztof; Grządziel, Dominik; Połednik, Bernard; Mazur, Jadwiga; Dudzińska, Marzenna R; Mroczek, Mariusz

    2014-12-01

    Radon and its decay products are harmful pollutants present in indoor air and are responsible for the majority of the effective dose due to ionising radiation that people are naturally exposed to. The paper presents the results of the series of measurements of radon and its progeny (in unattached and attached fractions) as well as indoor air parameters: temperature, relative humidity, number and mass concentrations of fine aerosol particles. The measurements were carried out in the auditorium (lecture hall), which is an indoor air quality laboratory, in controlled conditions during two periods of time: when air conditioning (AC) was switched off (unoccupied auditorium) and when it was switched on (auditorium in normal use). The significant influence of AC and of students' presence on the dynamics of radon and its progeny was confirmed. A decrease in the mean value of radon and its attached progeny was found when AC was working. The mean value of radon equilibrium factor F was also lower when AC was working (0.49) than when it was off (0.61). The linear correlations were found between attached radon progeny concentration and particle number and mass concentration only when the AC was switched off. This research is being conducted with the aim to study the variability of radon equilibrium factor F which is essential to determine the effective dose due to radon and its progeny inhalation.

  1. Air conditioning impact on the dynamics of radon and its daughters concentration.

    PubMed

    Kozak, Krzysztof; Grządziel, Dominik; Połednik, Bernard; Mazur, Jadwiga; Dudzińska, Marzenna R; Mroczek, Mariusz

    2014-12-01

    Radon and its decay products are harmful pollutants present in indoor air and are responsible for the majority of the effective dose due to ionising radiation that people are naturally exposed to. The paper presents the results of the series of measurements of radon and its progeny (in unattached and attached fractions) as well as indoor air parameters: temperature, relative humidity, number and mass concentrations of fine aerosol particles. The measurements were carried out in the auditorium (lecture hall), which is an indoor air quality laboratory, in controlled conditions during two periods of time: when air conditioning (AC) was switched off (unoccupied auditorium) and when it was switched on (auditorium in normal use). The significant influence of AC and of students' presence on the dynamics of radon and its progeny was confirmed. A decrease in the mean value of radon and its attached progeny was found when AC was working. The mean value of radon equilibrium factor F was also lower when AC was working (0.49) than when it was off (0.61). The linear correlations were found between attached radon progeny concentration and particle number and mass concentration only when the AC was switched off. This research is being conducted with the aim to study the variability of radon equilibrium factor F which is essential to determine the effective dose due to radon and its progeny inhalation. PMID:24375376

  2. Characterization of Francisella species isolated from the cooling water of an air conditioning system.

    PubMed

    Gu, Quan; Li, Xunde; Qu, Pinghua; Hou, Shuiping; Li, Juntao; Atwill, Edward R; Chen, Shouyi

    2015-01-01

    Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems. PMID:26413079

  3. Characterization of Francisella species isolated from the cooling water of an air conditioning system.

    PubMed

    Gu, Quan; Li, Xunde; Qu, Pinghua; Hou, Shuiping; Li, Juntao; Atwill, Edward R; Chen, Shouyi

    2015-01-01

    Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems.

  4. Energy Performance Comparison of Heating and Air Conditioning Systems for Multi-Family Residential Buildings

    SciTech Connect

    Wang, Weimin; Zhang, Jian; Jiang, Wei; Liu, Bing

    2011-07-31

    The type of heating, ventilation and air conditioning (HVAC) system has a large impact on the heating and cooling energy consumption in multifamily residential buildings. This paper compares the energy performance of three HVAC systems: a direct expansion (DX) split system, a split air source heat pump (ASHP) system, and a closed-loop water source heat pump (WSHP) system with a boiler and an evaporative fluid cooler as the central heating and cooling source. All three systems use gas furnace for heating or heating backup. The comparison is made in a number of scenarios including different climate conditions, system operation schemes and applicable building codes. It is found that with the minimum code-compliant equipment efficiency, ASHP performs the best among all scenarios except in extremely code climates. WSHP tends to perform better than the split DX system in cold climates but worse in hot climates.

  5. An efficient new automobile air-conditioning system based on CO{sub 2} vapor compression

    SciTech Connect

    Pettersen, J.

    1994-12-31

    A new, efficient, and environmentally safe automobile air-conditioning system based on carbon dioxide (CO{sub 2}) vapor compression has been developed. Although working pressures and component design are different, the basic principles are similar to those of current chlorofluorocarbon/hydrofluorocarbon (CFC/HFC) units. With the construction and testing of a laboratory prototype, it has been documented that the new system is highly competitive with current CFC-12 and HFC-134a units in terms of efficiency, capacity, cost, weight, and dimensions. The CO{sub 2} concept thus offers a solution to the environmental problem associated with automobile air conditioning and eliminates all uncertainties with respect to possible unforeseen effects from new refrigerant compounds. Further advantages of the natural fluid CO{sub 2} as a refrigerant are: no need for recycling or recovery, low cost of fluid, excellent availability, well-known properties, and more compact machinery and components.

  6. Characterization of Francisella species isolated from the cooling water of an air conditioning system

    PubMed Central

    Gu, Quan; Li, Xunde; Qu, Pinghua; Hou, Shuiping; Li, Juntao; Atwill, Edward R.; Chen, Shouyi

    2015-01-01

    Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems. PMID:26413079

  7. The Maintenance of Heating, Ventilating and Air-Conditioning Systems and Indoor Air Quality in Schools: A Guide for School Facility Managers. Technical Bulletin.

    ERIC Educational Resources Information Center

    Wheeler, Arthur E.

    To help maintain good indoor air quality (IAQ) in schools, guidance for the development and implementation of an effective program for maintenance and operation of heating, ventilating, and air-conditioning (HVAC) systems are discussed. Frequently, a building's occupants will complain about IAQ when the temperature or humidity are at uncomfortable…

  8. Potential emission savings from refrigeration and air conditioning systems by using low GWP refrigerants

    DOE PAGES

    Beshr, Mohamed; Aute, Vikrant; Abdelaziz, Omar; Fricke, Brian; Radermacher, Reinhard

    2016-08-24

    Refrigeration and air conditioning systems have high, negative environmental impacts due to refrigerant charge leaks from the system and their corresponding high global warming potential. Thus, many efforts are in progress to obtain suitable low GWP alternative refrigerants and more environmentally friendly systems for the future. In addition, the system’s life cycle climate performance (LCCP) is a widespread metric proposed for the evaluation of the system’s environmental impact.

  9. Application information on typical hygrometers used in heating, ventilating and air conditioning (HVAC) systems

    SciTech Connect

    Kao, J.Y.; Snyder, W.J.

    1982-01-01

    Hygrometer selection information is provided for application in heating, ventilating and air-conditioning (HVAC) systems. A general review of hygrometer literature has been provided and the most commonly used ones for HVAC are discussed. Typical hygrometer parameters are listed to indicate the type of performance that can be expected. Laboratory test results of self-regulating, salt-phase transition hygrometers are presented and discussed in detail.

  10. Retrofitting Inefficient Rooftop Air-Conditioning Units Reduces U.S. Navy Energy Use (Fact Sheet)

    SciTech Connect

    Not Available

    2014-04-01

    As part of the U.S. Navy's overall energy strategy, the National Renewable Energy Laboratory (NREL) partnered with the Naval Facilities Engineering Command (NAVFAC) to demonstrate market-ready energy efficiency measures, renewable energy generation, and energy systems integration. One such technology - retrofitting rooftop air-conditioning units with an advanced rooftop control system - was identified as a promising source for reducing energy use and costs, and can contribute to increasing energy security.

  11. Tourists’ attitudes towards ban on smoking in air-conditioned hotel lobbies in Thailand

    PubMed Central

    Viriyachaiyo, V; Lim, A

    2009-01-01

    Background: Thailand is internationally renowned for its stringent tobacco control measures. In Thailand, a regulation banning smoking in air-conditioned hotel lobbies was issued in late 2006, causing substantial apprehension within the hospitality industry. A survey of tourists’ attitudes toward the ban was conducted. Methods: A cross-sectional survey of 5550 travellers staying in various hotels in Bangkok, Surat Thani, Phuket, Krabi and Songkhla provinces, October 2005 to December 2006. Travellers aged 15 years or older with a check-in duration of at least one day and willing to complete the questionnaire were requested by hotel staff to fill in the 5-minute questionnaire at check-in or later at their convenience. Results: Secondhand cigarette smoke was recognised as harmful to health by 89.7% of respondents. 47.8% of travellers were aware of the Thai regulation banning smoking in air-conditioned restaurants. 80.9% of the respondents agreed with the ban, particularly female non-smokers. 38.6% of survey respondents indicated that they would be more likely to visit Thailand again because of the regulation, 53.4% that the regulation would not affect their decision and 7.9% that they would be less likely to visit Thailand again. Conclusion: Banning smoking in air-conditioned hotel lobbies in Thailand is widely supported by tourists. Enforcement of the regulation is more likely to attract tourists than dissuade them from holidaying in Thailand. PMID:19364754

  12. Validation of the criteria for initiating the cleaning of heating, ventilation, and air-conditioning (HVAC) ductwork under real conditions.

    PubMed

    Lavoie, Jacques; Marchand, Geneviève; Cloutier, Yves; Lavoué, Jérôme

    2011-08-01

    Dust accumulation in the components of heating, ventilation, and air-conditioning (HVAC) systems is a potential source of contaminants. To date, very little information is available on recognized methods for assessing dust buildup in these systems. The few existing methods are either objective in nature, involving numerical values, or subjective in nature, based on experts' judgments. An earlier project aimed at assessing different methods of sampling dust in ducts was carried out in the laboratories of the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST). This laboratory study showed that all the sampling methods were practicable, provided that a specific surface-dust cleaning initiation criterion was used for each method. However, these conclusions were reached on the basis of ideal conditions in a laboratory using a reference dust. The objective of this present study was to validate these laboratory results in the field. To this end, the laboratory sampling templates were replicated in real ducts and the three sampling methods (the IRSST method, the method of the U.S. organization National Air Duct Cleaner Association [NADCA] and that of the French organization Association pour la Prévention et l'Étude de la Contamination [ASPEC]) were used simultaneously in a statistically representative number of systems. The air return and supply ducts were also compared. Cleaning initiation criteria under real conditions were found to be 6.0 mg/100 cm(2) using the IRSST method, 2.0 mg/100 cm(2) using the NADCA method, and 23 mg/100 cm(2) using the ASPEC method. In the laboratory study, the criteria using the same methods were 6.0 for the IRSST method, 2.0 for the NADCA method, and 3.0 for the ASPEC method. The laboratory criteria for the IRSST and NADCA methods were therefore validated in the field. The ASPEC criterion was the only one to change. The ASPEC method therefore allows for the most accurate evaluation of dust accumulation in HVAC

  13. Validation of the criteria for initiating the cleaning of heating, ventilation, and air-conditioning (HVAC) ductwork under real conditions.

    PubMed

    Lavoie, Jacques; Marchand, Geneviève; Cloutier, Yves; Lavoué, Jérôme

    2011-08-01

    Dust accumulation in the components of heating, ventilation, and air-conditioning (HVAC) systems is a potential source of contaminants. To date, very little information is available on recognized methods for assessing dust buildup in these systems. The few existing methods are either objective in nature, involving numerical values, or subjective in nature, based on experts' judgments. An earlier project aimed at assessing different methods of sampling dust in ducts was carried out in the laboratories of the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST). This laboratory study showed that all the sampling methods were practicable, provided that a specific surface-dust cleaning initiation criterion was used for each method. However, these conclusions were reached on the basis of ideal conditions in a laboratory using a reference dust. The objective of this present study was to validate these laboratory results in the field. To this end, the laboratory sampling templates were replicated in real ducts and the three sampling methods (the IRSST method, the method of the U.S. organization National Air Duct Cleaner Association [NADCA] and that of the French organization Association pour la Prévention et l'Étude de la Contamination [ASPEC]) were used simultaneously in a statistically representative number of systems. The air return and supply ducts were also compared. Cleaning initiation criteria under real conditions were found to be 6.0 mg/100 cm(2) using the IRSST method, 2.0 mg/100 cm(2) using the NADCA method, and 23 mg/100 cm(2) using the ASPEC method. In the laboratory study, the criteria using the same methods were 6.0 for the IRSST method, 2.0 for the NADCA method, and 3.0 for the ASPEC method. The laboratory criteria for the IRSST and NADCA methods were therefore validated in the field. The ASPEC criterion was the only one to change. The ASPEC method therefore allows for the most accurate evaluation of dust accumulation in HVAC

  14. Self-assembly at Air/Water Interfaces and Carbohydrate Binding Properties of the Small Secreted Protein EPL1 from the fungus Trichoderma atroviride*

    PubMed Central

    Frischmann, Alexa; Neudl, Susanna; Gaderer, Romana; Bonazza, Klaus; Zach, Simone; Gruber, Sabine; Spadiut, Oliver; Friedbacher, Gernot; Grothe, Hinrich; Seidl-Seiboth, Verena

    2013-01-01

    The protein EPL1 from the fungus Trichoderma atroviride belongs to the cerato-platanin protein family. These proteins occur only in filamentous fungi and are associated with the induction of defense responses in plants and allergic reactions in humans. However, fungi with other lifestyles also express cerato-platanin proteins, and the primary function of this protein family has not yet been elucidated. In this study, we investigated the biochemical properties of the cerato-platanin protein EPL1 from T. atroviride. Our results showed that EPL1 readily self-assembles at air/water interfaces and forms protein layers that can be redissolved in water. These properties are reminiscent of hydrophobins, which are amphiphilic fungal proteins that accumulate at interfaces. Atomic force microscopy imaging showed that EPL1 assembles into irregular meshwork-like substructures. Furthermore, surface activity measurements with EPL1 revealed that, in contrast to hydrophobins, EPL1 increases the polarity of aqueous solutions and surfaces. In addition, EPL1 was found to bind to various forms of polymeric chitin. The T. atroviride genome contains three epl genes. epl1 was predominantly expressed during hyphal growth, whereas epl2 was mainly expressed during spore formation, suggesting that the respective proteins are involved in different biological processes. For epl3, no gene expression was detected under most growth conditions. Single and double gene knock-out strains of epl1 and epl2 did not reveal a detectable phenotype, showing that these proteins are not essential for fungal growth and development despite their abundant expression. PMID:23250741

  15. Towards energy efficient operation of Heating, Ventilation and Air Conditioning systems via advanced supervisory control design

    NASA Astrophysics Data System (ADS)

    Oswiecinska, A.; Hibbs, J.; Zajic, I.; Burnham, K. J.

    2015-11-01

    This paper presents conceptual control solution for reliable and energy efficient operation of heating, ventilation and air conditioning (HVAC) systems used in large volume building applications, e.g. warehouse facilities or exhibition centres. Advanced two-level scalable control solution, designed to extend capabilities of the existing low-level control strategies via remote internet connection, is presented. The high-level, supervisory controller is based on Model Predictive Control (MPC) architecture, which is the state-of-the-art for indoor climate control systems. The innovative approach benefits from using passive heating and cooling control strategies for reducing the HVAC system operational costs, while ensuring that required environmental conditions are met.

  16. Thermodynamic model of a thermal storage air conditioning system with dynamic behavior

    SciTech Connect

    Fleming, E; Wen, SY; Shi, L; da Silva, AK

    2013-12-01

    A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system's dynamic behavior, such as a dynamic air flow rate into the vehicle's cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle's cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid-air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semianalytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid-air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system experimental data for solidification using paraffin wax as the PCM. Through modeling, we demonstrate the importance of capturing the airside heat exchange impact on system performance, and we investigate system response to dynamic operating conditions, e.g., air recirculation. (C) 2013 Elsevier Ltd. All rights reserved.

  17. Heating, ventilating, and air conditioning deactivation thermal analysis of PUREX Plant

    SciTech Connect

    Chen, W.W.; Gregonis, R.A.

    1997-08-01

    Thermal analysis was performed for the proposed Plutonium Uranium Extraction Plant exhaust system after deactivation. The purpose of the analysis was to determine if enough condensation will occur to plug or damage the filtration components. A heat transfer and fluid flow analysis was performed to evaluate the thermal characteristics of the underground duct system, the deep-bed glass fiber filter No. 2, and the high-efficiency particulate air filters in the fourth filter building. The analysis is based on extreme variations of air temperature, relative humidity, and dew point temperature using 15 years of Hanford Site weather data as a basis. The results will be used to evaluate the need for the electric heaters proposed for the canyon exhaust to prevent condensation. Results of the analysis indicate that a condition may exist in the underground ductwork where the duct temperature can lead or lag changes in the ambient air temperature. This condition may contribute to condensation on the inside surfaces of the underground exhaust duct. A worst case conservative analysis was performed assuming that all of the water is removed from the moist air over the inside surface of the concrete duct area in the fully developed turbulent boundary layer while the moist air in the free stream will not condense. The total moisture accumulated in 24 hours is negligible. Water puddling would not be expected. The results of the analyses agree with plant operating experiences. The filters were designed to resist high humidity and direct wetting, filter plugging caused by slight condensation in the upstream duct is not a concern. 19 refs., 2 figs.

  18. Air Flow Path Dynamics In The Vadose Zone Under Various Land Surface Climate Boundary Conditions

    NASA Astrophysics Data System (ADS)

    Illangasekare, T. H.; Sakaki, T.; Schulte, P. E.; Cihan, A.; Christ, J.

    2010-12-01

    Vapor intrusion (VI) refers to the transport of volatile chemical vapors from subsurface sources to surface and subsurface structures through the vadose zone. Because of the difference in pressure between the inside of the building and the subsurface soil pores, vapor can enter the building through cracks in the foundation, slab and walls and utility openings. The processes that govern the vapor transport in the heterogeneous subsurface “outside the home” are complex, and the sampling to assess potential pathways is subjected to spatial and temporal variability. Spatial variability is a result of a number of factors that include changing soil and soil moisture conditions. Temporal variability is a result of transient heat, wind, ambient pressure and a water flux boundary conditions at the land-atmospheric interface. Fluctuating water table conditions controlled by recharge, pumping, and stream-aquifer interactions will also contribute to the transient vapor flux generation at the sources. When the soil moisture changes as a result of precipitation events and other soil surface boundary conditions, the soil moisture content changes and hence the air permeability. Therefore, the primary pathways for the vapor are preferential channels that change with the transient soil moisture distribution. Both field and laboratory studies have shown that heterogeneity has a significant influence on soil moisture conditions in unsaturated soils. Uncertainties in vapor transport predictions have been attributed to heterogeneity and spatial variability in hydraulic properties. In this study, our goal was to determine the role of soil moisture variability on vapor transport and intrusion as affected by the climate driven boundary conditions on the land surface. A series of experiments were performed to generate a comprehensive data set to understand and evaluate how the spatial and temporal variability of soil moisture affected by the mass and heat flux boundary conditions on the

  19. Performance of R-410A Alternative Refrigerants in a Reciprocating Compressor Designed for Air Conditioning Applications

    SciTech Connect

    Shrestha, Som S; Vineyard, Edward Allan; Mumpower, Kevin

    2016-01-01

    In response to environmental concerns raised by the use of refrigerants with high Global Warming Potential (GWP), the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) has launched an industry-wide cooperative research program, referred to as the Low-GWP Alternative Refrigerants Evaluation Program (AREP), to identify and evaluate promising alternative refrigerants for major product categories. After successfully completing the first phase of the program in December 2013, AHRI launched a second phase of the Low-GWP AREP in 2014 to continue research in areas that were not previously addressed, including refrigerants in high ambient conditions, refrigerants in applications not tested in the first phase, and new refrigerants identified since testing for the program began. Although the Ozone Depletion Potential of R-410A is zero, this refrigerant is under scrutiny due to its high GWP. Several candidate alternative refrigerants have already demonstrated low global warming potential. Performance of these low-GWP alternative refrigerants is being evaluated for Air conditioning and heat pump applications to ensure acceptable system capacity and efficiency. This paper reports the results of a series of compressor calorimeter tests conducted for the second phase of the AREP to evaluate the performance of R-410A alternative refrigerants in a reciprocating compressor designed for air conditioning systems. It compares performance of alternative refrigerants ARM-71A, L41-1, DR-5A, D2Y-60, and R-32 to that of R-410A over a wide range of operating conditions. The tests showed that, in general, cooling capacities were slightly lower (except for the R-32), but energy efficiency ratios (EER) of the alternative refrigerants were comparable to that of R-410A.

  20. High Efficiency Integrated Space Conditioning, Water Heating and Air Distribution System for HUD-Code Manufactured Housing

    SciTech Connect

    Henry DeLima; Joe Akin; Joseph Pietsch

    2008-09-14

    Recognizing the need for new space conditioning and water heating systems for manufactured housing, DeLima Associates assembled a team to develop a space conditioning system that would enhance comfort conditions while also reducing energy usage at the systems level. The product, Comboflair® was defined as a result of a needs analysis of project sponsors and industry stakeholders. An integrated system would be developed that would combine a packaged airconditioning system with a small-duct, high-velocity air distribution system. In its basic configuration, the source for space heating would be a gas water heater. The complete system would be installed at the manufactured home factory and would require no site installation work at the homesite as is now required with conventional split-system air conditioners. Several prototypes were fabricated and tested before a field test unit was completed in October 2005. The Comboflair® system, complete with ductwork, was installed in a 1,984 square feet, double-wide manufactured home built by Palm Harbor Homes in Austin, TX. After the home was transported and installed at a Palm Harbor dealer lot in Austin, TX, a data acquisition system was installed for remote data collection. Over 60 parameters were continuously monitored and measurements were transmitted to a remote site every 15 minutes for performance analysis. The Comboflair® system was field tested from February 2006 until April 2007. The cooling system performed in accordance with the design specifications. The heating system initially could not provide the needed capacity at peak heating conditions until the water heater was replaced with a higher capacity standard water heater. All system comfort goals were then met. As a result of field testing, we have identified improvements to be made to specific components for incorporation into production models. The Comboflair® system will be manufactured by Unico, Inc. at their new production facility in St. Louis

  1. Photocatalytic elimination of indoor air biological and chemical pollution in realistic conditions.

    PubMed

    Sánchez, Benigno; Sánchez-Muñoz, Marta; Muñoz-Vicente, María; Cobas, Guillermo; Portela, Raquel; Suárez, Silvia; González, Aldo E; Rodríguez, Nuria; Amils, Ricardo

    2012-05-01

    The photocatalytic elimination of microorganisms from indoor air in realistic conditions and the feasibility of simultaneous elimination of chemical contaminants have been studied at laboratory scale. Transparent polymeric monoliths have been coated with sol-gel TiO(2) films and used as photocatalyst to treat real indoor air in a laboratory-scale single-step annular photocatalytic reactor. The analytical techniques used to characterize the air quality and analyze the results of the photocatalytic tests were: colony counting, microscopy and PCR with subsequent sequencing for microbial quantification and identification; automated thermal desorption coupled to gas chromatography with mass spectrometry detection for chemical analysis. The first experiments performed proved that photocatalysis based on UVA-irradiated TiO(2) for the reduction of the concentration of bacteria in the air could compete with the conventional photolytic treatment with UVC radiation, more expensive and hazardous. Simultaneously to the disinfection, the concentration of volatile organic compounds was greatly reduced, which adds value to this technology for real applications. The fungal colony number was not apparently modified.

  2. Study on an Efficient Dehumidifying Air-conditioning System utilizing Phase Change of Intermediate Pressure Refrigerant

    NASA Astrophysics Data System (ADS)

    Maeda, Kensaku; Inaba, Hideo

    The present study has proven a new dehumidifying system that aimed to reduce the sensible heat factor(SHF) of cooling process without using additional heat to relieve the internationally indicated conflict between energy saving and dehumidification necessary for keeping adequate indoor air quality (IAQ). In this system, we used intermediate pressure refrigerant in a vapor compression refrigerating cycle as heat transfer medium of a characteristic heat exchanger to precool the process air entering into an evaporator as well as to reheat the process air leaving from the evaporator. By this system, the present results achieved higher moisture removal and consequently higher efficiency of dehumidifying process. In addition to this fact, since this system has capability of integration into air-conditioning apparatus(HVAC system), it will be able to work for wide range of cooling load by variable SHF function. In the present paper, technical information, experimental results, and simulation results which assumed to apply this system into HVAC system are reported.

  3. TECNAIRE winter field campaign: turbulent characteristics and their influence on air quality conditions

    NASA Astrophysics Data System (ADS)

    Yagüe, Carlos; Román Cascón, Carlos; Maqueda, Gregorio; Sastre, Mariano; Arrillaga, Jon A.; Artíñano, Begoña; Diaz-Ramiro, Elías; Gómez-Moreno, Francisco J.; Borge, Rafael; Narros, Adolfo; Pérez, Javier

    2016-04-01

    An urban field campaign was conducted at an air pollution hot spot in Madrid city (Spain) during winter 2015 (from 16th February to 2nd March). The zone selected for the study is a square (Plaza Fernández Ladreda) located in the southern part of the city. This area is an important intersection of several principal routes, and therefore a significant impact in the air quality of the area is found due to the high traffic density. Meteorological data (wind speed and direction, air temperature, relative humidity, pressure, precipitation and global solar radiation) were daily recorded as well as micrometeorological measurements obtained from two sonic anemometers. To characterize this urban atmospheric boundary layer (uABL), micrometeorological parameters (turbulent kinetic energy -TKE-, friction velocity -u∗- and sensible heat flux -H-) are calculated, considering 5-minute average for variance and covariance evaluations. Furthermore, synoptic atmospheric features were analyzed. As a whole, a predominant influence of high pressure systems was found over the Atlantic Ocean and western Spain, affecting Madrid, but during a couple of days (17th and 21st February) some atmospheric instability played a role. The influence of the synoptic situation and specially the evolution of the micrometeorological conditions along the day on air quality characteristics (Particulate Matter concentrations: PM10, PM2.5 and PM1, and NOx concentrations) are analyzed and shown in detail. This work has been financed by Madrid Regional Research Plan through TECNAIRE (P2013/MAE-2972).

  4. Self-Assembly and Lipid Interactions of Diacylglycerol Lactone Derivatives Studied at the Air/Water Interface

    PubMed Central

    Philosof-Mazor, Liron; Volinsky, Roman; Comin, Maria J.; Lewin, Nancy E.; Kedei, Noemi; Blumberg, Peter M.; Marquez, Victor E.; Jelinek, Raz

    2009-01-01

    Synthetic diacylglycerol lactones (DAG-lactones) have been shown to be effective modulators of critical cellular signaling pathways. The biological activity of these amphiphilic molecules depends in part upon their lipid interactions within the cellular plasma membrane. This study explores the thermodynamic and structural features of DAG-lactone derivatives and their lipid interactions at the air/water interface. Surface-pressure/area isotherms and Brewster angle microscopy revealed the significance of specific side-groups attached to the terminus of a very rigid 4-(2-phenylethynyl) benzoyl chain of the DAG-lactones, which affected both the self-assembly of the molecules and their interactions with phospholipids. The experimental data highlight the formation of different phases within mixed DAG-lactone/phospholipid monolayers and underscore the relationship between the two components in binary mixtures of different mole ratios. Importantly, the results suggest that DAG-lactones are predominantly incorporated within fluid phospholipid phases rather than in the condensed phases that form, for example, by cholesterol. Moreover, the size and charge of the phospholipid headgroups do not seem to affect DAG-lactone interactions with lipids. PMID:18788772

  5. Positional isomers of linear sodium dodecyl benzene sulfonate: solubility, self-assembly, and air/water interfacial activity.

    PubMed

    Ma, Jian-Guo; Boyd, Ben J; Drummond, Calum J

    2006-10-10

    Commercial linear alkyl benzene sulfonates (ABS) are a very important class of anionic surfactants that are employed in a wide variety of applications, especially those involving wetting and detergency. Linear ABS surfactants generally consist of a complex mixture of different chain lengths and positional isomers. This diversity and level of complexity makes it difficult to develop fundamental structure-property correlations for the commercial surfactants. In this work, six monodisperse headgroup positional isomers of sodium para-dodecyl benzene sulfonate (Na-x-DBS, x = 1-6) have been studied. The influence of headgroup position and added electrolyte (NaCl) on the solubility and self-assembly (micellar and vesicular aggregation and lyotropic liquid crystalline phase behavior) in the temperature range from 10 to 90 degrees C have been investigated. Additionally, the air-aqueous solution interfacial adsorption at 25 (no added NaCl) and 50 degrees C (from 0 to 1.0 M added NaCl) has been examined. The observed physicochemical behavior is interpreted in terms of local molecular packing constraints, and in the case of the lyotropic liquid crystalline behavior global aggregate packing constraints as well.

  6. Supramolecular chiral self-assembly and supercoiling behavior of carrageenans at varying salt conditions

    NASA Astrophysics Data System (ADS)

    Schefer, Larissa; Adamcik, Jozef; Diener, Michael; Mezzenga, Raffaele

    2015-10-01

    The self-assembly of anionic kappa and iota carrageenan polysaccharides in the presence of NaCl, KCl and CaCl2 is studied by high-resolution atomic force microscopy (AFM). A hierarchical supramolecular chirality amplification over various length scales is observed upon the addition of KCl, whereas in the presence of NaCl and CaCl2 the chains undergo solely a coil-helix transition with stiff kappa carrageenan and more flexible iota carrageenan helical conformations.The self-assembly of anionic kappa and iota carrageenan polysaccharides in the presence of NaCl, KCl and CaCl2 is studied by high-resolution atomic force microscopy (AFM). A hierarchical supramolecular chirality amplification over various length scales is observed upon the addition of KCl, whereas in the presence of NaCl and CaCl2 the chains undergo solely a coil-helix transition with stiff kappa carrageenan and more flexible iota carrageenan helical conformations. Electronic supplementary information (ESI) available: Details on materials, sample preparation and purification, further AFM images and corresponding analysis. See DOI: 10.1039/c5nr04525h

  7. Ground-water conditions at Beale Air Force Base and vicinity, California

    USGS Publications Warehouse

    Page, R.W.

    1980-01-01

    Ground-water conditions were studied in a 168-square-mile area between the Sierra Nevada and the Feather River in Yuba County, Calif. The area is in the eastern part of the Sacramento Valley and includes most of Beale Air Force Base. Source, occurrence, movement, and chemical quality of the ground water were evaluated. Ground water occurs in sedimentary and volcanic rocks of Tertiary and Quaternary age. The base of the freshwater is in the undifferentiated sedimentary rocks of Oligocene and Eocene age, that contain water of high dissolved-solids concentration. The ground water occurs under unconfined and partly confined conditions. At Beale Air Force Base it is at times partly confined. Recharge is principally from the rivers. Pumpage in the study area was estimated to be 129,000 acre-feet in 1975. In the 1960's, water levels in most parts of the study area declined less rapidly than in earlier years or became fairly stable. In the 1970's, water levels at Beale Air Force Base declined only slightly. Spacing of wells on the base and rates of pumping are such that excessive pumping interference is avoided. Water quality at the base and throughout the study area is generally good. Dissolved-solids concentrations are 700 to 900 milligrams per liter in the undifferentiated sedimentary rocks beneath the base well field. (USGS)

  8. Experimental performance study of a proposed desiccant based air conditioning system.

    PubMed

    Bassuoni, M M

    2014-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system. PMID:25685475

  9. Experimental performance study of a proposed desiccant based air conditioning system.

    PubMed

    Bassuoni, M M

    2014-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system.

  10. Experimental performance study of a proposed desiccant based air conditioning system

    PubMed Central

    Bassuoni, M.M.

    2013-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system. PMID:25685475

  11. An Analysis of Price Determination and Markups in the Air-Conditioning and Heating Equipment Industry

    SciTech Connect

    Dale, Larry; Millstein, Dev; Coughlin, Katie; Van Buskirk, Robert; Rosenquist, Gregory; Lekov, Alex; Bhuyan, Sanjib

    2004-01-30

    In this report we calculate the change in final consumer prices due to minimum efficiency standards, focusing on a standard economic model of the air-conditioning and heating equipment (ACHE) wholesale industry. The model examines the relationship between the marginal cost to distribute and sell equipment and the final consumer price in this industry. The model predicts that the impact of a standard on the final consumer price is conditioned by its impact on marginal distribution costs. For example, if a standard raises the marginal cost to distribute and sell equipment a small amount, the model predicts that the standard will raise the final consumer price a small amount as well. Statistical analysis suggest that standards do not increase the amount of labor needed to distribute equipment the same employees needed to sell lower efficiency equipment can sell high efficiency equipment. Labor is a large component of the total marginal cost to distribute and sell air-conditioning and heating equipment. We infer from this that standards have a relatively small impact on ACHE marginal distribution and sale costs. Thus, our model predicts that a standard will have a relatively small impact on final ACHE consumer prices. Our statistical analysis of U.S. Census Bureau wholesale revenue tends to confirm this model prediction. Generalizing, we find that the ratio of manufacturer price to final consumer price prior to a standard tends to exceed the ratio of the change in manufacturer price to the change in final consumer price resulting from a standard. The appendix expands our analysis through a typical distribution chain for commercial and residential air-conditioning and heating equipment.

  12. Meteorological conditions are associated with physical activities performed in open-air settings

    NASA Astrophysics Data System (ADS)

    Suminski, Richard R.; Poston, Walker C.; Market, Patrick; Hyder, Melissa; Sara, Pyle A.

    2008-01-01

    Meteorological conditions (MC) are believed to modify physical activity. However, studies in this area are limited and none have looked at the associations between MC and physical activity in open-air settings. Therefore, we examined the relationships between MC and physical activities performed on sidewalks/streets and outdoor oval tracks. Observation techniques were used to count individuals walking to school, exercising on oval tracks and walking/jogging/biking on sidewalks/streets. Meteorological conditions were obtained from an Automated Surface Observing System located at a nearby airport for the same time periods physical activities were observed. On weekdays, fewer children were seen walking to school and more bicyclists were observed on sidewalks/streets as wind speed increased ( p < 0.05). Ambient and apparent temperatures were positively ( p < 0.05) and humidity and barometric pressure negatively ( p < 0.005) related to the number of individuals walking on the track. Meteorological conditions were not significantly associated with physical activities observed on weekends. Multiple linear regression analyses showed that apparent temperature (+), barometric pressure (-) and dew point (-) accounted for 58.0% of the variance in the number of walkers on the track. A significant proportion of the variance (>30%) in the number of joggers and the length of time they jogged was accounted for by apparent temperature (+) and dew point (-). We found that meteorological conditions are related to physical activity in open-air settings. The results embellish the context in which environmental-physical activity relationships should be interpreted and provide important information for researchers applying the observation method in open-air settings.

  13. LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery

    DOEpatents

    Ko, Suk M.

    1980-01-01

    This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.

  14. Cascade Reverse Osmosis Air Conditioning System: Cascade Reverse Osmosis and the Absorption Osmosis Cycle

    SciTech Connect

    2010-09-01

    BEETIT Project: Battelle is developing a new air conditioning system that uses a cascade reverse osmosis (RO)-based absorption cycle. Analyses show that this new cycle can be as much as 60% more efficient than vapor compression, which is used in 90% of air conditioners. Traditional vapor-compression systems use polluting liquids for a cooling effect. Absorption cycles use benign refrigerants such as water, which is absorbed in a salt solution and pumped as liquid—replacing compression of vapor. The refrigerant is subsequently separated from absorbing salt using heat for re-use in the cooling cycle. Battelle is replacing thermal separation of refrigerant with a more efficient reverse osmosis process. Research has shown that the cycle is possible, but further investment will be needed to reduce the number of cascade reverse osmosis stages and therefore cost.

  15. The Oklahoma Field Test: Air-conditioning electricity savings from standard energy conservation measures, radiant barriers, and high-efficiency window air conditioners

    SciTech Connect

    Ternes, M.P.; Levins, W.P.

    1992-08-01

    A field test Involving 104 houses was performed in Tulsa, Oklahoma, to measure the air-conditioning electricity consumption of low-income houses equipped with window air conditioners, the reduction in this electricity consumption attributed to the installation of energy conservation measures (ECMS) as typically installed under the Oklahoma Weatherization Assistance Program (WAP), and the reduction achieved by the replacement of low-efficiency window air conditioners with high-efficiency units and the installation of attic radiant barriers. Air-conditioning electricity consumption and indoor temperature were monitored weekly during the pre-weatherization period (June to September 1988) and post-weatherization period (May to September 1989). House energy consumption models and regression analyses were used to normalize the air-conditioning electricity savings to average outdoor temperature conditions and the pre-weatherization indoor temperature of each house. The following conclusions were drawn from the study: (1) programs directed at reducing air-conditioning electricity consumption should be targeted at clients with high consumption to improve cost effectiveness; (2) replacing low-efficiency air conditioners with high-efficiency units should be considered an option in a weatherization program directed at reducing air-conditioning electricity consumption; (3) ECMs currently being installed under the Oklahoma WAP (chosen based on effectiveness at reducing space-heating energy consumption) should continue to be justified based on their space-heating energy savings potential only; and (4) attic radiant barriers should not be included in the Oklahoma WAP if alternatives with verified savings are available or until further testing demonstrates energy savings or other benefits in this typo of housing.

  16. In-car particles and cardiovascular health: an air conditioning-based intervention study.

    PubMed

    Chuang, Hsiao-Chi; Lin, Lian-Yu; Hsu, Ya-Wen; Ma, Chih-Ming; Chuang, Kai-Jen

    2013-05-01

    Exposure to traffic-related particulate matter (PM) is considered a potential risk for cardiovascular events. Little is known about whether improving air quality in car can modify cardiovascular effects among human subjects during commuting. We recruited a panel of 60 healthy subjects to commute for 2 h by a car equipped with an air conditioning (AC) system during the morning rush hour in Taipei. Operation modes of AC system using outside air (OA-mode), circulating inside air (IA-mode) and turning off (Off-mode) were examined. Repeated measurements of heart rate variability (HRV) indices, PM≤2.5 μm in aerodynamic diameter (PM2.5) and noise level were conducted for each participant in different modes during the commute. We used linear mixed-effects models to associate HRV indices with in-car PM2.5. We found that decreases in HRV indices were associated with increased levels of in-car PM2.5. For Off-mode, an interquartile range (IQR) increase in in-car PM2.5 with 15-min moving average was associated with 2.7% and 4.1% decreases in standard deviation of NN intervals (SDNN) and the square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD), respectively. During OA and IA modes, participants showed slight decreases in SDNN (OA mode: 0.1%; IA mode: 1.3%) and r-MSSD (OA mode: 1.1%; IA mode: 1.8%) by an IQR increase in in-car PM2.5 with 15-min moving average. We concluded that in-car PM2.5 is associated with autonomic alteration. Utilization of the car's AC system can improve air quality and modify the effects of in-car PM2.5 on HRV indices among human subjects during the commute.

  17. The Oklahoma Field Test: Air-Conditioning Electricity Savings from Standard Energy Conservation Measures, Radiant Barriers, and High-Efficiency Window Air Conditioners

    SciTech Connect

    Ternes, M.P.

    1992-01-01

    A field test involving 104 houses was performed in Tulsa, Oklahoma, to measure the air-conditioning electricity consumption of low-income houses equipped with window air conditioners, the reduction in this electricity consumption attributed to the installation of energy conservation measures (ECMs) as typically installed under the Oklahoma Weatherization Assistance Program (WAP), and the reduction achieved by the replacement of low-efficiency window air conditioners with high-efficiency units and the installation of attic radiant barriers. Air-conditioning electricity consumption and indoor temperature were monitored weekly during the pre-weatherization period (June to September 1988) and post-weatherization period (May to September 1989). House energy consumption models and regression analyses were used to normalize the air-conditioning electricity savings to average outdoor temperature conditions and the pre-weatherization indoor temperature of each house. The average measured pre-weatherization air-conditioning electricity consumption was 1664 kWh/year ($119/year). Ten percent of the houses used less than 250 kWh/year, while another 10% used more than 3000 kWh/year. An average reduction in air-conditioning electricity consumption of 535 kWh/year ($38/year and 28% of pre-weatherization consumption) was obtained from replacement of one low-efficiency window air conditioner (EER less than 7.0) per house with a high-efficiency unit (EER greater than 9.0). For approximately the same cost, savings tripled to 1503 kWh/year ($107/year and 41% of pre-weatherization consumption) in those houses with initial air-conditioning electricity consumption greater than 2750 kWh/year. For these houses, replacement of a low-efficiency air conditioner with a high-efficiency unit was cost effective using the incremental cost of installing a new unit now rather than later; the average installation cost for these houses under a weatherization program was estimated to be $786. The

  18. Proposal for a Vehicle Level Test Procedure to Measure Air Conditioning Fuel Use

    SciTech Connect

    Rugh, J. P.

    2010-04-01

    The air-conditioning (A/C) compressor load significantly impacts the fuel economy of conventional vehicles and the fuel use/range of plug-in hybrid electric vehicles (PHEV). A National Renewable Energy Laboratory (NREL) vehicle performance analysis shows the operation of the air conditioner reduces the charge depletion range of a 40-mile range PHEV from 18% to 30% in a worst case hot environment. Designing for air conditioning electrical loads impacts PHEV and electric vehicle (EV) energy storage system size and cost. While automobile manufacturers have climate control procedures to assess A/C performance, and the U.S. EPA has the SCO3 drive cycle to measure indirect A/C emissions, there is no automotive industry consensus on a vehicle level A/C fuel use test procedure. With increasing attention on A/C fuel use due to increased regulatory activities and the development of PHEVs and EVs, a test procedure is needed to accurately assess the impact of climate control loads. A vehicle thermal soak period is recommended, with solar lamps that meet the SCO3 requirements or an alternative heating method such as portable electric heaters. After soaking, the vehicle is operated over repeated drive cycles or at a constant speed until steady-state cabin air temperature is attained. With this method, the cooldown and steady-state A/C fuel use are measured. This method can be run at either different ambient temperatures to provide data for the GREEN-MAC-LCCP model temperature bins or at a single representative ambient temperature. Vehicles with automatic climate systems are allowed to control as designed, while vehicles with manual climate systems are adjusted to approximate expected climate control settings. An A/C off test is also run for all drive profiles. This procedure measures approximate real-world A/C fuel use and assess the impact of thermal load reduction strategies.

  19. Fuel-Free Compressed-Air Energy Storage: Fuel-Free, Ubiquitous Compressed-Air Energy Storage and Power Conditioning

    SciTech Connect

    2010-09-13

    GRIDS Project: General Compression has developed a transformative, near-isothermal compressed air energy storage system (GCAES) that prevents air from heating up during compression and cooling down during expansion. When integrated with renewable generation, such as a wind farm, intermittent energy can be stored in compressed air in salt caverns or pressurized tanks. When electricity is needed, the process is reversed and the compressed air is expanded to produce electricity. Unlike conventional compressed air energy storage (CAES) projects, no gas is burned to convert the stored high-pressure air back into electricity. The result of this breakthrough is an ultra-efficient, fully shapeable, 100% renewable and carbon-free power product. The GCAES™ system can provide high quality electricity and ancillary services by effectively integrating renewables onto the grid at a cost that is competitive with gas, coal and nuclear generation.

  20. Performance Analysis of Air-to-Water Heat Pump in Latvian Climate Conditions

    NASA Astrophysics Data System (ADS)

    Kazjonovs, Janis; Sipkevics, Andrejs; Jakovics, Andris; Dancigs, Andris; Bajare, Diana; Dancigs, Leonards

    2014-12-01

    Strategy of the European Union in efficient energy usage demands to have a higher proportion of renewable energy in the energy market. Since heat pumps are considered to be one of the most efficient heating and cooling systems, they will play an important role in the energy consumption reduction in buildings aimed to meet the target of nearly zero energy buildings set out in the EU Directive 2010/31/EU. Unfortunately, the declared heat pump Coefficient of Performance (COP) corresponds to a certain outdoor temperature (+7 °C), therefore different climate conditions, building characteristics and settings result in different COP values during the year. The aim of this research is to investigate the Seasonal Performance factor (SPF) values of air-to-water heat pump which better characterize the effectiveness of heat pump in a longer selected period of time, especially during the winter season, in different types of residential buildings in Latvian climate conditions. Latvia has four pronounced seasons of near-equal length. Winter starts in mid-December and lasts until mid-March. Latvia is characterized by cold, maritime climate (duration of the average heating period being 203 days, the average outdoor air temperature during the heating period being 0.0 °C, the coldest five-day average temperature being -20.7 °C, the average annual air temperature being +6.2 °C, the daily average relative humidity being 79 %). The first part of this research consists of operational air-towater heat pump energy performance monitoring in different residential buildings during the winter season. The second part of the research takes place under natural conditions in an experimental construction stand which is located in an urban environment in Riga, Latvia. The inner area of this test stand, where air-to-water heat pump performance is analyzed, is 9 m2. The ceiling height is 3 m, all external wall constructions (U = 0.16 W/(m2K)) have ventilated facades. To calculate SPF, the

  1. Cool Roofs in Guangzhou, China: Outdoor Air Temperature Reductions during Heat Waves and Typical Summer Conditions.

    PubMed

    Cao, Meichun; Rosado, Pablo; Lin, Zhaohui; Levinson, Ronnen; Millstein, Dev

    2015-12-15

    In this paper, we simulate temperature reductions during heat-wave events and during typical summer conditions from the installation of highly reflective "cool" roofs in the Chinese megacity of Guangzhou. We simulate temperature reductions during six of the strongest historical heat-wave events over the past decade, finding average urban midday temperature reductions of 1.2 °C. In comparison, we simulate 25 typical summer weeks between 2004 and 2008, finding average urban midday temperature reductions of 0.8 °C, indicating that air temperature sensitivity to urban albedo in Guangzhou varies with meteorological conditions. We find that roughly three-fourths of the variance in air temperature reductions across all episodes can be accounted for by a linear regression, including only three basic properties related to the meteorological conditions: mean daytime temperature, humidity, and ventilation to the greater Guangzhou urban area. While these results highlight the potential for cool roofs to mitigate peak temperatures during heat waves, the temperature reductions reported here are based on the upper bound case, which increases albedos of all roofs (but does not modify road albedo or wall albedo).

  2. Cool Roofs in Guangzhou, China: Outdoor Air Temperature Reductions during Heat Waves and Typical Summer Conditions.

    PubMed

    Cao, Meichun; Rosado, Pablo; Lin, Zhaohui; Levinson, Ronnen; Millstein, Dev

    2015-12-15

    In this paper, we simulate temperature reductions during heat-wave events and during typical summer conditions from the installation of highly reflective "cool" roofs in the Chinese megacity of Guangzhou. We simulate temperature reductions during six of the strongest historical heat-wave events over the past decade, finding average urban midday temperature reductions of 1.2 °C. In comparison, we simulate 25 typical summer weeks between 2004 and 2008, finding average urban midday temperature reductions of 0.8 °C, indicating that air temperature sensitivity to urban albedo in Guangzhou varies with meteorological conditions. We find that roughly three-fourths of the variance in air temperature reductions across all episodes can be accounted for by a linear regression, including only three basic properties related to the meteorological conditions: mean daytime temperature, humidity, and ventilation to the greater Guangzhou urban area. While these results highlight the potential for cool roofs to mitigate peak temperatures during heat waves, the temperature reductions reported here are based on the upper bound case, which increases albedos of all roofs (but does not modify road albedo or wall albedo). PMID:26523605

  3. Vibro-acoustic characterization of flexible hose in CO2 car air conditioning systems

    NASA Astrophysics Data System (ADS)

    Angelini, F.; Bergami, A.; Martarelli, M.; Tomasini, E. P.

    2008-06-01

    Following the EU directive 2006/40/EC proscribing from 2011 that refrigerant fluids must have a global warming potential not higher than 150, it will not be allowed anymore to employ the current R134a on car air conditioning systems. Maflow s.p.a (automotive hose maker) is developing products for each possible new refrigerant. This paper is focused on hoses for CO2 refrigerants operating in the worst conditions because of the high pressures and temperatures at which they are working (with R134a the high pressure is 18 bar and low pressure is 3 bar; with CO2 the high pressure is 100 bar and low pressure is 35 bar). Therefore the noise emission control of the CO2 air conditioning systems is very important. The aim of this study is to develop a standard measurement method for the vibro - acoustic characterization of High Pressure (HP - Shark F4) and Low Pressure (LP - ULEV) hoses to reduce noise emission and raise car passenger comfort; in particular deep research on high pressure hose. The method is based on the measurement of the vibration level of the hoses in a standard test bench by means of a Laser Doppler Vibrometer (LDV) and its acoustic emission by a sound intensity probe.

  4. Experimental investigation of static ice refrigeration air conditioning system driven by distributed photovoltaic energy system

    NASA Astrophysics Data System (ADS)

    Xu, Y. F.; Li, M.; Luo, X.; Wang, Y. F.; Yu, Q. F.; Hassanien, R. H. E.

    2016-08-01

    The static ice refrigeration air conditioning system (SIRACS) driven by distributed photovoltaic energy system (DPES) was proposed and the test experiment have been investigated in this paper. Results revealed that system energy utilization efficiency is low because energy losses were high in ice making process of ice slide maker. So the immersed evaporator and co-integrated exchanger were suggested in system structure optimization analysis and the system COP was improved nearly 40%. At the same time, we have researched that ice thickness and ice super-cooled temperature changed along with time and the relationship between system COP and ice thickness was obtained.

  5. TRUMP-BD: A computer code for the analysis of nuclear fuel assemblies under severe accident conditions

    SciTech Connect

    Lombardo, N.J.; Marseille, T.J.; White, M.D.; Lowery, P.S.

    1990-06-01

    TRUMP-BD (Boil Down) is an extension of the TRUMP (Edwards 1972) computer program for the analysis of nuclear fuel assemblies under severe accident conditions. This extension allows prediction of the heat transfer rates, metal-water oxidation rates, fission product release rates, steam generation and consumption rates, and temperature distributions for nuclear fuel assemblies under core uncovery conditions. The heat transfer processes include conduction in solid structures, convection across fluid-solid boundaries, and radiation between interacting surfaces. Metal-water reaction kinetics are modeled with empirical relationships to predict the oxidation rates of steam-exposed Zircaloy and uranium metal. The metal-water oxidation models are parabolic in form with an Arrhenius temperature dependence. Uranium oxidation begins when fuel cladding failure occurs; Zircaloy oxidation occurs continuously at temperatures above 13000{degree}F when metal and steam are available. From the metal-water reactions, the hydrogen generation rate, total hydrogen release, and temporal and spatial distribution of oxide formations are computed. Consumption of steam from the oxidation reactions and the effect of hydrogen on the coolant properties is modeled for independent coolant flow channels. Fission product release from exposed uranium metal Zircaloy-clad fuel is modeled using empirical time and temperature relationships that consider the release to be subject to oxidation and volitization/diffusion ( bake-out'') release mechanisms. Release of the volatile species of iodine (I), tellurium (Te), cesium (Ce), ruthenium (Ru), strontium (Sr), zirconium (Zr), cerium (Cr), and barium (Ba) from uranium metal fuel may be modeled.

  6. Estimating the risks of smoking, air pollution, and passive smoke on acute respiratory conditions

    SciTech Connect

    Ostro, B.D. )

    1989-06-01

    Five years of the annual Health Interview Survey, conducted by the National Center for Health Statistics, are used to estimate the effects of air pollution, smoking, and environmental tobacco smoke on respiratory restrictions in activity for adults, and bed disability for children. After adjusting for several socioeconomic factors, the multiple regression estimates indicate that an independent and statistically significant association exists between these three forms of air pollution and respiratory morbidity. The comparative risks of these exposures are computed and the plausibility of the relative risks is examined by comparing the equivalent doses with actual measurements of exposure taken in the homes of smokers. The results indicate that: (1) smokers will have a 55-75% excess in days with respiratory conditions severe enough to cause reductions in normal activity; (2) a 1 microgram increase in fine particulate matter air pollution is associated with a 3% excess in acute respiratory disease; and (3) a pack-a-day smoker will increase respiratory restricted days for a nonsmoking spouse by 20% and increase the number of bed disability days for young children living in the household by 20%. The results also indicate that the estimates of the effects of secondhand smoking on children are improved when the mother's work status is known and incorporated into the exposure estimate.

  7. The interaction of water mists and premixed propane-air flames under low-gravity conditions

    NASA Astrophysics Data System (ADS)

    Abbud-Madrid, Angel; Riedel, Edward P.; McKinnon, J. Thomas

    1999-01-01

    A preliminary investigation of the effect of water mists on premixed flame propagation in a cylindrical tube under low-gravity conditions has been conducted to define the scientific and technical objectives of the experiments to be performed on the Space Shuttle and International Space Station microgravity environments. The inhibiting characteristics of water mists in propagating flames of propane-air mixtures at various equivalence ratios are studied. The effects of droplet size and concentration on the laminar flame speed are used as the measure of fire suppression efficacy. Flame speed and propagation behavior are monitored by a video camera. Reduced gravity is obtained with an aircraft flying parabolic trajectories. Measurements and qualitative observations from the low-gravity experiments clearly show the effect of water mist on flame speed abatement, flame shape, and radiant emission. For lean propane-air mixtures, the flame speed increases at first with low water-mist concentrations and then decreases below its dry value when higher water-mist volumes are introduced in the tube. This phenomenon may be due in part to the heating of the unburned mixture ahead of the flame as a result of radiation absorption by the water droplets. For rich propane-air mixtures, similar behavior of flame speed vs. water concentration is encountered but in this case is mostly due to the formation of cellular flames. At high water loads both lean and rich flames exhibit extinction before reaching the end of the tube.

  8. Estimating the risks of smoking, air pollution, and passive smoke on acute respiratory conditions.

    PubMed

    Ostro, B D

    1989-06-01

    Five years of the annual Health Interview Survey, conducted by the National Center for Health Statistics, are used to estimate the effects of air pollution, smoking, and environmental tobacco smoke on respiratory restrictions in activity for adults, and bed disability for children. After adjusting for several socioeconomic factors, the multiple regression estimates indicate that an independent and statistically significant association exists between these three forms of air pollution and respiratory morbidity. The comparative risks of these exposures are computed and the plausibility of the relative risks is examined by comparing the equivalent doses with actual measurements of exposure taken in the homes of smokers. The results indicate that: (1) smokers will have a 55-75% excess in days with respiratory conditions severe enough to cause reductions in normal activity; (2) a 1 microgram increase in fine particulate matter air pollution is associated with a 3% excess in acute respiratory disease; and (3) a pack-a-day smoker will increase respiratory restricted days for a nonsmoking spouse by 20% and increase the number of bed disability days for young children living in the household by 20%. The results also indicate that the estimates of the effects of secondhand smoking on children are improved when the mother's work status is known and incorporated into the exposure estimate.

  9. Molecular modeling of directed self-assembly of block copolymers: Fundamental studies of processing conditions and evolutionary pattern design

    NASA Astrophysics Data System (ADS)

    Khaira, Gurdaman Singh

    Rapid progress in the semi-conductor industry has pushed for smaller feature sizes on integrated electronic circuits. Current photo-lithographic techniques for nanofabrication have reached their technical limit and are problematic when printing features small enough to meet future industrial requirements. "Bottom-up'' techniques, such as the directed self-assembly (DSA) of block copolymers (BCP), are the primary contenders to compliment current "top-down'' photo-lithography ones. For industrial requirements, the defect density from DSA needs to be less than 1 defect per 10 cm by 10 cm. Knowledge of both material synthesis and the thermodynamics of the self-assembly process are required before optimal operating conditions can be found to produce results adequate for industry. The work present in this thesis is divided into three chapters, each discussing various aspects of DSA as studied via a molecular model that contains the essential physics of BCP self-assembly. Though there are various types of guiding fields that can be used to direct BCPs over large wafer areas with minimum defects, this study focuses only on chemically patterned substrates. The first chapter addresses optimal pattern design by describing a framework where molecular simulations of various complexities are coupled with an advanced optimization technique to find a pattern that directs a target morphology. It demonstrates the first ever study where BCP self-assembly on a patterned substrate is optimized using a three-dimensional description of the block-copolymers. For problems pertaining to DSA, the methodology is shown to converge much faster than the traditional random search approach. The second chapter discusses the metrology of BCP thin films using TEM tomography and X-ray scattering techniques, such as CDSAXS and GISAXS. X-ray scattering has the advantage of being able to quickly probe the average structure of BCP morphologies over large wafer areas; however, deducing the BCP morphology

  10. Acaroid mite allergens from the filters of air-conditioning system in China.

    PubMed

    Li, Chao-Pin; Guo, Wei; Zhan, Xiao-Dong; Zhao, Bei-Bei; Diao, Ji-Dong; Li, Na; He, Lian-Ping

    2014-01-01

    Accumulation of acaroid mites in the filters of air-conditioners is harmful to human health. It is important to clarify the allergen components of mites from the filters of local air-conditioning system. The present study was to detect the allergen types in the filters of air-conditioners and assesse their allergenicity by asthmatic models. Sixty aliquots of dust samples were collected from air conditioning filters in civil houses in Wuhu area. Total protein was extracted from the dust samples using PBS and quantified by Bradford method. Allergens I and II were also detected by Western blot using primary antibody (anti-Der f1/2, Der p1/Der f2/Der p2, respectively). Ten aliquots of the positive samples were randomly selected for homogenization and sensitized the mice for developing asthmatic animal models. Total serum IgE level and IFN-γ, IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). The allergenicity of the extraction was assessed using pathological sections developed from the mouse pulmonary tissues. The concentration of extract from the 60 samples was ranged from 4.37 μg/ml to 30.76 μg/ml. After analyzing with Western blot, 31 of 60 samples were positive for 4 allergens of acaroid mites, and yet 16 were negative. The levels of total IgE from serum IL-4 and IL-5 from the BALF in the experimental group were apparently higher than that of negative control and PBS group (P < 0.01), but there were no statistical difference compared to OVA group (P > 0.05). However,the IFN-γ level in BALF was lower compared with the negative control and PBS group (P < 0.05) but with the OVA group (P > 0.05). The pathological changes were evidently emerged in pulmonary tissues, which were similar to those of OVA group, compared with the PBS ground and negative controls. The air-conditioner filters in human dwellings of Wuhu area potentially contain the major group allergen 1 and 2 from D. farinae and D. pteronyssinus, which may be associated with seasonal prevalence of

  11. Acaroid mite allergens from the filters of air-conditioning system in China

    PubMed Central

    Li, Chao-Pin; Guo, Wei; Zhan, Xiao-Dong; Zhao, Bei-Bei; Diao, Ji-Dong; Li, Na; He, Lian-Ping

    2014-01-01

    Accumulation of acaroid mites in the filters of air-conditioners is harmful to human health. It is important to clarify the allergen components of mites from the filters of local air-conditioning system. The present study was to detect the allergen types in the filters of air-conditioners and assesse their allergenicity by asthmatic models. Sixty aliquots of dust samples were collected from air conditioning filters in civil houses in Wuhu area. Total protein was extracted from the dust samples using PBS and quantified by Bradford method. Allergens I and II were also detected by Western blot using primary antibody (anti-Der f1/2, Der p1/Der f2/Der p2, respectively). Ten aliquots of the positive samples were randomly selected for homogenization and sensitized the mice for developing asthmatic animal models. Total serum IgE level and IFN-γ, IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). The allergenicity of the extraction was assessed using pathological sections developed from the mouse pulmonary tissues. The concentration of extract from the 60 samples was ranged from 4.37 μg/ml to 30.76 μg/ml. After analyzing with Western blot, 31 of 60 samples were positive for 4 allergens of acaroid mites, and yet 16 were negative. The levels of total IgE from serum IL-4 and IL-5 from the BALF in the experimental group were apparently higher than that of negative control and PBS group (P < 0.01), but there were no statistical difference compared to OVA group (P > 0.05). However,the IFN-γ level in BALF was lower compared with the negative control and PBS group (P < 0.05) but with the OVA group (P > 0.05). The pathological changes were evidently emerged in pulmonary tissues, which were similar to those of OVA group, compared with the PBS ground and negative controls. The air-conditioner filters in human dwellings of Wuhu area potentially contain the major group allergen 1 and 2 from D. farinae and D. pteronyssinus, which may be associated with seasonal prevalence of

  12. Acaroid mite allergens from the filters of air-conditioning system in China.

    PubMed

    Li, Chao-Pin; Guo, Wei; Zhan, Xiao-Dong; Zhao, Bei-Bei; Diao, Ji-Dong; Li, Na; He, Lian-Ping

    2014-01-01

    Accumulation of acaroid mites in the filters of air-conditioners is harmful to human health. It is important to clarify the allergen components of mites from the filters of local air-conditioning system. The present study was to detect the allergen types in the filters of air-conditioners and assesse their allergenicity by asthmatic models. Sixty aliquots of dust samples were collected from air conditioning filters in civil houses in Wuhu area. Total protein was extracted from the dust samples using PBS and quantified by Bradford method. Allergens I and II were also detected by Western blot using primary antibody (anti-Der f1/2, Der p1/Der f2/Der p2, respectively). Ten aliquots of the positive samples were randomly selected for homogenization and sensitized the mice for developing asthmatic animal models. Total serum IgE level and IFN-γ, IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). The allergenicity of the extraction was assessed using pathological sections developed from the mouse pulmonary tissues. The concentration of extract from the 60 samples was ranged from 4.37 μg/ml to 30.76 μg/ml. After analyzing with Western blot, 31 of 60 samples were positive for 4 allergens of acaroid mites, and yet 16 were negative. The levels of total IgE from serum IL-4 and IL-5 from the BALF in the experimental group were apparently higher than that of negative control and PBS group (P < 0.01), but there were no statistical difference compared to OVA group (P > 0.05). However,the IFN-γ level in BALF was lower compared with the negative control and PBS group (P < 0.05) but with the OVA group (P > 0.05). The pathological changes were evidently emerged in pulmonary tissues, which were similar to those of OVA group, compared with the PBS ground and negative controls. The air-conditioner filters in human dwellings of Wuhu area potentially contain the major group allergen 1 and 2 from D. farinae and D. pteronyssinus, which may be associated with seasonal prevalence of

  13. Self-assembly mechanism of nanoparticles of Ni-based Prussian Blue analogues at the air/liquid interface: a synchrotron X-ray reflectivity study.

    PubMed

    Giner-Casares, Juan J; Clemente-León, Miguel; Coronado, Eugenio; Brezesinski, Gerald

    2015-08-24

    Prussian Blue analogue (PBA) nanoparticles can be self-assembled at air/liquid interfaces to build novel materials with interesting magnetic features. Herein, we study the influence of the size of PBA Cs0.4 Ni[Cr(CN)6 ]0.9 and K0.25 Ni[Fe(CN)6 ]0.75 nanoparticles on the self-assembly behavior by synchrotron X-ray reflectivity. Both nanoparticles show similar Z-potential values. The phospholipid dipalmitoylphosphatidylcholine and the amino surfactant dimethyldioctadecylammonium have been used as Langmuir monolayers to anchor the PBA nanoparticles and study the interplay of forces directing the self-assembly of the nanoparticles at the surfactant/liquid interface. Whereas Cs0.4 Ni[Cr(CN)6 ]0.9 nanoparticles with a diameter of 8 nm form an incomplete layer at the surfactant/water interface, the larger K0.25 Ni[Fe(CN)6 ]0.75 nanoparticles with a diameter of 20 nm generate complete layers that can be stacked to one another. The size of the PBA nanoparticles is the main parameter determining the final arrangement at the air/liquid interface, due to the different extent of interparticle interaction. This study aims at the rationale design of PBA nanoparticles for an effective interfacial self-assembly, ultimately leading to functional materials.

  14. Choanoflagellate lorica construction and assembly: the nudiform condition. II. Acanthoeca spectabilis Ellis.

    PubMed

    Leadbeater, Barry S C; Henouil, Magali; Berovic, Nikolas

    2008-07-01

    Acanthoeca spectabilis is one of the most common loricate choanoflagellates found in marine biofilms everywhere. However, it is special for two reasons; firstly, it is probably the most distinctive member of the small nudiform clade of loricate choanoflagellates. Secondly, the lorica chamber of Acanthoeca comprises a closely wound left-handed coil of costae that is unique amongst choanoflagellates. Mathematical analysis of the lorica chamber shows that the helical costae undergo two turns. This species, more than any, demonstrates that the helical coiling of costae can only be achieved by a rotational movement generated by the cell during lorica assembly. Comparison of the lorica morphology of Acanthoeca with that of the closely related genus Polyoeca indicates that the helical costae of Acanthoeca are probably homologous with the outer longitudinal costae of Polyoeca. This is unusual because helical costae are usually the innermost layer of costae. However, since there is no 'true' inner layer in the chamber of Acanthoeca the outer layer of costae are adjacent to the cell surface and therefore available for coiling. In contrast to tectiform choanoflagellates, which number more than one hundred species and inhabit a wide variety of microniches, the six known extant nudiform species must either represent a minor evolutionary development or be the remnants of a previously more extensive radiation.

  15. Arduino-based control system for measuring ammonia in air using conditionally-deployed diffusive samplers

    NASA Astrophysics Data System (ADS)

    Ham, J. M.; Williams, C.; Shonkwiler, K. B.

    2012-12-01

    Arduino microcontrollers, wireless modules, and other low-cost hardware were used to develop a new type of air sampler for monitoring ammonia at strong areal sources like dairies, cattle feedlots, and waste treatment facilities. Ammonia was sampled at multiple locations on the periphery of an operation using Radiello diffusive passive samplers (Cod. RAD168- and RAD1201-Sigma-Aldrich). However, the samplers were not continuously exposed to the air. Instead, each sampling station included two diffusive samplers housed in specialized tubes that sealed the cartridges from the atmosphere. If a user-defined set of wind and weather conditions were met, the Radiellos were deployed into the air using a micro linear actuator. Each station was solar-powered and controlled by Arduinos that were linked to a central weather station using Xbee wireless modules (Digi International Inc.). The Arduinos also measured the total time of exposure using hall-effect sensors to verify the position of the cartridge (i.e., deployed or retracted). The decision to expose or retract the samplers was made every five minutes based on wind direction, wind speed, and time of day. Typically, the diffusive samplers were replaced with fresh cartridges every two weeks and the used samplers were analyzed in the laboratory using ion chromatography. Initial studies were conducted at a commercial dairy in northern Colorado. Ammonia emissions along the Front Range of Colorado can be transported into the mountains where atmospheric deposition of nitrogen can impact alpine ecosystems. Therefore, low-cost air quality monitoring equipment is needed that can be widely deployed in the region. Initial work at the dairy showed that ammonia concentrations ranged between 600 to 1200 ppb during the summer; the highest concentrations were downwind of a large anaerobic lagoon. Time-averaged ammonia concentrations were also used to approximate emissions using inverse dispersion models. This methodology provides a

  16. Meteorological factors and air pollution in Lithuanian forests: possible effects on tree condition.

    PubMed

    Ozolincius, Remigijus; Stakenas, Vidas; Serafinaviciute, Brigita

    2005-10-01

    This study investigates changes in tree condition and environmental factors in Lithuania during the active growing season in 1991-2001. The average crown defoliation and the proportion of healthy trees of Pinus sylvestris, Picea abies, Betula sp., Fraxinus excelsior, Alnus incana, Alnus glutinosa, Populus tremula, and Quercus robur, meteorological (average temperature, amount of precipitation, hydrothermal coefficient) and air pollution data (acidity of precipitation, concentrations of SO2, NO2 and exposure of O3) were analysed. During the period 1991-2001 the condition of Pinus sylvestris, Populus tremula showed a tendency of improvement, while defoliation of Fraxinus excelsior significantly increased. The proportion of healthy trees correlated well with the average temperature and O3 (AOT40), while defoliation correlated well with the acidity of precipitation and the concentrations of SO2 and NO2. Deciduous species appeared to be more sensitive to O3 exposure and conifers to the concentrations of SO2 and NO2.

  17. 40 CFR 86.1868-12 - CO2 credits for improving the efficiency of air conditioning systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., interior volume, climate control system type and characteristics, refrigerant used, compressor type, and... recirculated air when the operator or the automatic climate control system has engaged the air conditioning... subsequent vehicle operations (i.e., next vehicle start). The climate control system may delay switching...

  18. Air pollution, forest condition and forest decline in Southern Europe: an overview.

    PubMed

    Bussotti, F; Ferretti, M

    1998-01-01

    Over the last decades much of the work on the impact of air pollution on forests in Europe has concentrated on central and northern countries. The southern part of Europe has received far less attention, although air pollutants-especially the photochemical ones-can reach concentrations likely to have adverse effects on forest vegetation. Although international forest condition surveys present serious problems where data consistency is concerned, they reveal considerable year-by-year species-specific fluctuations rather than a large-scale forest decline. Cases of obvious decline related to environmental factors are well circumscribed: (1) the deterioration of some coastal forests due to the action of polluted seaspray; (2) the deterioration of reforestation projects, especially conifers, mainly due to the poor ecological compatibility between species and site; and (3) the decline of deciduous oaks in southern Italy and of evergreen oaks in the Iberian peninsula apparently due to the interaction of climate stresses and pests and diseases. However, besides obvious deterioration, changes in environmental factors can provoke situations of more subtle stress. The most sensitive stands are Mediterranean conifer forests and mesophile forests of the Mediterranean-montane plane growing at the edges of the natural ecological distribution. Evergreen sclerophyllous forests appear less sensitive to variations in climatic parameters, since they can adapt quite well to both drought and the action of UV-B rays. Several experiments were carried out to test the sensitivity of Mediterranean forest species to air pollutants. Most of those experiments used seedlings of different species treated with pollutant concentrations too high to be realistic, so it is difficult to derive adequate information on the response of adult trees in field conditions. Ozone has been proved to cause foliar injury in a variety of native forest species in different Southern European countries, while the

  19. Effect of sea sprays on air-sea momentum exchange at severe wind conditions

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yu.; Ezhova, E.; Semenova, A.; Soustova, I.

    2012-04-01

    Wind-wave interaction at extreme wind speed is of special interest now in connection with the problem of explanation of the sea surface drag saturation at the wind speed exceeding 30 m/s. The idea on saturation (and even reduction) of the coefficient of aerodynamic resistance of the sea surface at hurricane wind speed was first suggested in [1] on the basis of theoretical analysis of sensitivity of maximum wind speed in a hurricane to the ratio of the enthalpy and momentum exchange coefficients. Both field [2-4] and laboratory [5] experiments confirmed that at hurricane wind speed the sea surface drag coefficient is significantly reduced in comparison with the parameterization obtained at moderate to strong wind conditions. Two groups of possible theoretical mechanisms for explanation of the effect of the sea surface drag reduction can be specified. In the first group of models developed in [6,7], the sea surface drag reduction is explained by peculiarities of the air flow over breaking waves. Another approach more appropriate for the conditions of developed sea exploits the effect of sea drops and sprays on the wind-wave momentum exchange. Papers[8,9] focused on the effect of the sea drops on stratification of the air-sea boundary layer similar to the model of turbulent boundary layer with the suspended particles [10], while papers [11-13] estimated the momentum exchange of sea drops and air-flow. A mandatory element of the spray induced momentum flux is a parameterization of the momentum exchange between droplets and air flow, which determines the "source function" in the momentum balance equation. In this paper a model describing the motion of a spume droplet, the wind tear away from the crest of a steep surface wave, and then falling into the water. We consider two models for the injection of droplets into the air flow. The first one assumes that the drop starts from the surface at the orbital velocity of the wave. In the second model we consider droplets from

  20. Microbial communities related to volatile organic compound emission in automobile air conditioning units.

    PubMed

    Diekmann, Nina; Burghartz, Melanie; Remus, Lars; Kaufholz, Anna-Lena; Nawrath, Thorben; Rohde, Manfred; Schulz, Stefan; Roselius, Louisa; Schaper, Jörg; Mamber, Oliver; Jahn, Dieter; Jahn, Martina

    2013-10-01

    During operation of mobile air conditioning (MAC) systems in automobiles, malodours can occur. We studied the microbial communities found on contaminated heat exchanger fins of 45 evaporators from car MAC systems which were operated in seven different regions of the world and identified corresponding volatile organic compounds. Collected biofilms were examined by scanning electron microscopy and fluorescent in situ hybridization. The detected bacteria were loosely attached to the metal surface. Further analyses of the bacteria using PCR-based single-strand conformation polymorphism and sequencing of isolated 16S rRNA gene fragments identified highly divergent microbial communities with multiple members of the Alphaproteobacteriales, Methylobacteria were the prevalent bacteria. In addition, Sphingomonadales, Burkholderiales, Bacillales, Alcanivorax spp. and Stenotrophomonas spp. were found among many others depending on the location the evaporators were operated. Interestingly, typical pathogenic bacteria related to air conditioning systems including Legionella spp. were not found. In order to determine the nature of the chemical compounds produced by the bacteria, the volatile organic compounds were examined by closed loop stripping analysis and identified by combined gas chromatography/mass spectrometry. Sulphur compounds, i.e. di-, tri- and multiple sulphides, acetylthiazole, aromatic compounds and diverse substituted pyrazines were detected. Mathematical clustering of the determined microbial community structures against their origin identified a European/American/Arabic cluster versus two mainly tropical Asian clusters. Interestingly, clustering of the determined volatiles against the origin of the corresponding MAC revealed a highly similar pattern. A close relationship of microbial community structure and resulting malodours to the climate and air quality at the location of MAC operation was concluded.

  1. Visibility characteristics and the impacts of air pollutants and meteorological conditions over Shanghai, China.

    PubMed

    Xue, Dan; Li, Chengfan; Liu, Qian

    2015-06-01

    In China, visibility condition has become an important issue that concerns both society and the scientific community. In order to study visibility characteristics and its influencing factors, visibility data, air pollutants, and meteorological data during the year 2013 were obtained over Shanghai. The temporal variation of atmospheric visibility was analyzed. The mean value of daily visibility of Shanghai was 19.1 km. Visibility exhibited an obvious seasonal cycle. The maximum and minimum visibility occurred in September and December with the values of 27.5 and 7.7 km, respectively. The relationships between the visibility and air pollutant data were calculated. The visibility had negative correlation with NO2, CO, PM2.5, PM10, and SO2 and weak positive correlation with O3. Meteorological data were clustered into four groups to reveal the joint contribution of meteorological variables to the daily average visibility. Usually, under the meteorological condition of high temperature and wind speed, the visibility of Shanghai reached about 25 km, while visibility decreased to 16 km under the weather type of low wind speed and temperature and high relative humid. Principle component analysis was also applied to identify the main cause of visibility variance. The results showed that the low visibility over Shanghai was mainly due to the high air pollution concentrations associated with low wind speed, which explained the total variance of 44.99 %. These results provide new knowledge for better understanding the variations of visibility and have direct implications to supply sound policy on visibility improvement in Shanghai.

  2. Benefits of Leapfrogging to Superefficiency and Low Global Warming Potential Refrigerants in Room Air Conditioning

    SciTech Connect

    Shah, Nihar K.; Wei, Max; Letschert, Virginie; Phadke, Amol A.

    2015-10-01

    Hydrofluorocarbons (HFCs) emitted from uses such as refrigerants and thermal insulating foam, are now the fastest growing greenhouse gases (GHGs), with global warming potentials (GWP) thousands of times higher than carbon dioxide (CO2). Because of the short lifetime of these molecules in the atmosphere,1 mitigating the amount of these short-lived climate pollutants (SLCPs) provides a faster path to climate change mitigation than control of CO2 alone. This has led to proposals from Africa, Europe, India, Island States, and North America to amend the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) to phase-down high-GWP HFCs. Simultaneously, energy efficiency market transformation programs such as standards, labeling and incentive programs are endeavoring to improve the energy efficiency for refrigeration and air conditioning equipment to provide life cycle cost, energy, GHG, and peak load savings. In this paper we provide an estimate of the magnitude of such GHG and peak electric load savings potential, for room air conditioning, if the refrigerant transition and energy efficiency improvement policies are implemented either separately or in parallel.

  3. Joule-Thomson cryocooler with neon and nitrogen mixture using commercial air-conditioning compressors

    NASA Astrophysics Data System (ADS)

    Lee, Jisung; Oh, Haejin; Baek, Seungwhan; Lee, Cheonkyu; Jeong, Sangkwon

    2014-01-01

    A 2-stage mixed refrigerant (MR) Joule-Thomson (JT) cryocooler was designed for cooling high temperature superconducting cable below 70 K. The low temperature cycle was to operate with neon-nitrogen mixture, and the required compression ratio was approximately 24 when the suction pressure was 100 kPa. The high compression ratio of 24, the low pressure of 100 kPa at compressor suction, and the working fluid with high heat of compression were challenging issues to existing typical compression systems. We developed an innovative compression system with commercial oil-lubricated air-conditioning compressors. They were 2-stage rotary compressors originally designed for R410Aand connected in series. The compressors were modified to accommodate effective intercooling at every stage to alleviate compressor overheating problem. Additionally, fine-grade three-stage oil filters, an adsorber, and driers were installed at the discharge line to avoid a potential clogging problem from oil mist and moisture at low temperature sections. The present compression system was specifically demonstrated with a neon-nitrogen MR JT cryocooler. The operating pressure ratio was able to meet the designed specifications, and the recorded no-load mini mum temperature was 63.5 K . Commercial air-conditioning compressors were successfully applied to the high-c ompression ratio MR JT cryocooler with adequate modification using off-the-shelf components.

  4. Energy and global warming impacts of next generation refrigeration and air conditioning technologies

    SciTech Connect

    Sand, J.R.; Fischer, S.K.; Baxter, V.D.

    1996-10-01

    Significant developments have occurred in hydrofluorocarbon (HFC) and the application of ammonia and hydrocarbons as refrigerant working fluids since the original TEWI (Total Equivalent Warming Impact) report in 1991. System operating and performance data on alternative refrigerants and refrigeration technologies justify and updated evaluation of these new alternative refrigerants and competing technologies in well-characterized applications. Analytical and experimental results are used to show quantitative comparisons between HFCS, HFC blends, hydrocarbons, and ammonia, used as refrigerants. An objective evaluation is presented for commercial and near commercial non-CFC refrigerants/blowing agents and alternative refrigeration technologies. This information is needed for objective and quantitative decisions on policies addressing greenhouse gas emissions from refrigeration and air conditioning equipment. The evaluation assesses the energy use and global warming impacts of refrigeration and air conditioning technologies that could be commercialized during the phase out of HCFCS. Quantitative comparison TEWI for two application areas are presented. Opportunities for significant reductions in TEWI are seen with currently known refrigerants through improved maintenance and servicing practices and improved product designs.

  5. [Airborne Fungal Aerosol Concentration and Distribution Characteristics in Air- Conditioned Wards].

    PubMed

    Zhang, Hua-ling; Feng, He-hua; Fang, Zi-liang; Wang, Ben-dong; Li, Dan

    2015-04-01

    The effects of airborne fungus on human health in the hospital environment are related to not only their genera and concentrations, but also their particle sizes and distribution characteristics. Moreover, the mechanisms of aerosols with different particle sizes on human health are different. Fungal samples were obtained in medicine wards of Chongqing using a six-stage sampler. The airborne fungal concentrations, genera and size distributions of all the sampling wards were investigated and identified in detail. Results showed that airborne fungal concentrations were not correlated to the diseases or personnel density, but were related to seasons, temperature, and relative humidity. The size distribution rule had roughly the same for testing wards in winter and summer. The size distributions were not related with diseases and seasons, the percentage of airborne fungal concentrations increased gradually from stage I to stage III, and then decreased dramatically from stage V to stage VI, in general, the size of airborne fungi was a normal distribution. There was no markedly difference for median diameter of airborne fungi which was less 3.19 μm in these wards. There were similar dominant genera in all wards. They were Aspergillus spp, Penicillium spp and Alternaria spp. Therefore, attention should be paid to improve the filtration efficiency of particle size of 1.1-4.7 μm for air conditioning system of wards. It also should be targeted to choose appropriate antibacterial methods and equipment for daily hygiene and air conditioning system operation management.

  6. Gas Engine-Driven Heat Pump Chiller for Air-Conditioning and Hot Water Supply Systems

    NASA Astrophysics Data System (ADS)

    Fujita, Toshihiko; Mita, Nobuhiro; Moriyama, Tadashi; Hoshino, Norimasa; Kimura, Yoshihisa

    In Part 1 of this study, the performance characteristics of a 457kW gas engine-driven heat pump (GHP) chiller have been obtained from a simulation model analysis for both cooling and heating modes and it has been found that the part-load characteristics of the GHP chiller are fairly well. On the back of Part 1, a computer simulation program has been developed for the evaluation of GHP chiller systems to compare with the other types of heat source systems for air-conditioning and hot water supply applications. The simulation program can be used to estimate annual energy consumption, annual CO2 emission, etc. of the systems with the data of monthly and hourly thermal loads on various buildings, outdoor air conditions, and characteristics of various components comprising the systems. By applying this to some cases of medium-scale hotel, office, shop, and hospital buildings, it has been found that the GHP chiller systems have advantages particularly in the cases of hotels and hospitals where a lot of hot water demand exists. It has also been found that the combination of a GHP chiller and a direct-fired absorption water chiller boiler (hot and chilled water generator) appears promising.

  7. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong.

    PubMed

    Yan, H H; Guo, H; Ou, J M

    2014-08-15

    During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO2-equivelant (CO2-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10(5)tons CO2-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong.

  8. Energy studies on central and variable refrigerant flow air-conditioning systems

    NASA Astrophysics Data System (ADS)

    Abdullah, H.; Nitamakwuavan, S.; Jalaludin, A. F.

    2012-06-01

    Air-conditioning is a major contributor to energy end-use in commercial buildings. Different types of airconditioning systems are installed in commercial buildings including packaged systems, split units and central systems. With the advancement in control technology and the demand for energy efficient systems, variable refrigerant flow (VRF) air-conditioning system is seen to be a solution to the load-matching problem for airconditioning systems. In a VRF system, the volume or flow rate of the refrigerant is accurately matched to the required cooling load thereby saving energy and providing more accurate control. This study aims to determine the performance of the VRF system used in an actual building by calculating the Coefficient of Performance (COP) of the system. The COP is then compared to the COP of a centralized chilled water system used in the same building. The results showed that the COPs determined for the VRF and central systems are 3.3 and 2.0 respectively. The results also indicated that replacing older central system with a VRF system could lead to an energy savings of up to 39.5%.

  9. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong.

    PubMed

    Yan, H H; Guo, H; Ou, J M

    2014-08-15

    During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO2-equivelant (CO2-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10(5)tons CO2-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong. PMID:24997256

  10. Review of open-cycle desiccant air-conditioning concepts and systems

    SciTech Connect

    Wurm, J.

    1986-08-01

    This paper attempts to overview the development status of desiccant cooling. Over the past 30 years of progressively intensifying attention, this promising technology has become a domain of interest of many research agencies and manufacturing companies. As a result, the market potential for machines based on desiccant processes, particularly in comfort cooling and agricultural applications, is getting close to realization. One of the most important incentives of developing heat-activated, open-cycle desiccant cooling machines (air conditioners) has always been its potential simplicity. Such premise has been deceiving to a degree that in many instances has slowed the progress. However, the persistent analytical and material research brought some desiccant systems close to the marketplace. They provide attractive alternatives to consumers and utilities, offering particularly effective humidity and temperature control in cases of high fresh-air-makeup requirements. The control of bacteria, airborne particulates, as well as CO/sub 2/, combined with effective heating capability make them attractive for controlled-atmosphere agriculture. Finally, the capability of using low-temperature waste heat to drive the cycle becomes an important attribute of a desiccant concept, specifically when combined with a regular vapor-compression cooling machine in energy saving space-conditioning concepts. The presented assessment concludes that, particularly for specialized applications, machines based on open-cycle desiccant cooling processes are very close to playing an important role in the space-conditioning (including comfort control) marketplace.

  11. Fringing coral reef condition decline: assembling the puzzle of human impact associated to coastal development.

    NASA Astrophysics Data System (ADS)

    Garza-Perez, J. R.; Lopez-Patoni, A.; Naranjo-Garcia, M. J.

    2014-12-01

    Coral cover at Akumal fringing coral reef decreased 50% in a 13 yr. period, while the adjacent coastal zone increased its human-modified surface (associated to urban-tourist development) in 192%. In the same period, the number of local residents only increased 20% (1088 to1362) but the visitors did in 50% from ca. 200,000 to ca. 300,000. In this coastal zone, the phreatic acts as a storage of nutrients and pollutants from sources related to human activity, thus having a chronic run-off towards the reef, with acute episodes during the rainy season, specially during the anomalous rainy season of 2013. Using videotransects for monitoring the benthic reef components, changes were detected: from 2000 to 2013 the algae cover increased 166%, the reef condition and the reef structure indexes decreased in 50%, and coral diseases incidence increased 25% after a spike increment of 150% in 2010. The role of anthropogenic-stress indicators (population, modified land area, nutrients) was explored along reef condition indicators (reef structure and diversity indexes, topographic complexity, benthic cover and coral diseases incidence) via spatial analysis and multivariate statistics. Spatial patterns of the change in reef condition derived from high-resolution satellite imagery also provided insight for the stressors analysis and their relationships along the study period. Stress indicators (land-modified area and population) are correlated to decreases in coral cover and in reef structure. Direct stressors as sedimentation, nutrients and pollutants seem to be related to the decrease in overall reef condition, although time-series data is lacking; the contextual interpretation of their effects, paired with benthic condition characteristics suggest a strong relationship between these stressors and the decrease in the condition of the reef.

  12. Influence of operating conditions on the air gasification of dry refinery sludge in updraft gasifier

    NASA Astrophysics Data System (ADS)

    Ahmed, R.; Sinnathambi, C. M.

    2013-06-01

    In the present work, details of the equilibrium modeling of dry refinery sludge (DRS) are presented using ASPEN PLUS Simulator in updraft gasifier. Due to lack of available information in the open journal on refinery sludge gasification using updraft gasifier, an evaluate for its optimum conditions on gasification is presented in this paper. For this purpose a Taguchi Orthogonal array design, statistical software is applied to find optimum conditions for DRS gasification. The goal is to identify the most significant process variable in DRS gasification conditions. The process variables include; oxidation zone temperature, equivalent ratio, operating pressure will be simulated and examined. Attention was focused on the effect of optimum operating conditions on the gas composition of H2 and CO (desirable) and CO2 (undesirable) in terms of mass fraction. From our results and finding it can be concluded that the syngas (H2 & CO) yield in term of mass fraction favors high oxidation zone temperature and at atmospheric pressure while CO2 acid gas favor at a high level of equivalent ratio as well as air flow rate favoring towards complete combustion.

  13. The effect of simulated air conditions on N95 filtering facepiece respirators performance.

    PubMed

    Ramirez, Joel A; O'Shaughnessy, Patrick T

    2016-07-01

    The objective of this study was to determine the effect of several simulated air environmental conditions on the particle penetration and the breathing resistance of two N95 filtering facepiece respirator (FFR) models. The particle penetration and breathing resistance of the respirators were evaluated in a test system developed to mimic inhalation and exhalation breathing while relative humidity and temperature were modified. Breathing resistance was measured over 120 min using a calibrated pressure transducer under four different temperature and relative humidity conditions without aerosol loading. Particle penetration was evaluated before and after the breathing resistance test at room conditions using a sodium chloride aerosol measured with a scanning mobility particle sizer. Results demonstrated that increasing relative humidity and lowering external temperature caused significant increases in breathing resistance (p < 0.001). However, these same conditions did not influence the penetration or most penetrating particle size of the tested FFRs. The increase in breathing resistance varied by FFR model suggesting that some FFR media are less influenced by high relative humidity. PMID:26861653

  14. The effect of simulated air conditions on N95 filtering facepiece respirators performance.

    PubMed

    Ramirez, Joel A; O'Shaughnessy, Patrick T

    2016-07-01

    The objective of this study was to determine the effect of several simulated air environmental conditions on the particle penetration and the breathing resistance of two N95 filtering facepiece respirator (FFR) models. The particle penetration and breathing resistance of the respirators were evaluated in a test system developed to mimic inhalation and exhalation breathing while relative humidity and temperature were modified. Breathing resistance was measured over 120 min using a calibrated pressure transducer under four different temperature and relative humidity conditions without aerosol loading. Particle penetration was evaluated before and after the breathing resistance test at room conditions using a sodium chloride aerosol measured with a scanning mobility particle sizer. Results demonstrated that increasing relative humidity and lowering external temperature caused significant increases in breathing resistance (p < 0.001). However, these same conditions did not influence the penetration or most penetrating particle size of the tested FFRs. The increase in breathing resistance varied by FFR model suggesting that some FFR media are less influenced by high relative humidity.

  15. Experimental investigation on the photovoltaic-thermal solar heat pump air-conditioning system on water-heating mode

    SciTech Connect

    Fang, Guiyin; Hu, Hainan; Liu, Xu

    2010-09-15

    An experimental study on operation performance of photovoltaic-thermal solar heat pump air-conditioning system was conducted in this paper. The experimental system of photovoltaic-thermal solar heat pump air-conditioning system was set up. The performance parameters such as the evaporation pressure, the condensation pressure and the coefficient of performance (COP) of heat pump air-conditioning system, the water temperature and receiving heat capacity in water heater, the photovoltaic (PV) module temperature and the photovoltaic efficiency were investigated. The experimental results show that the mean photovoltaic efficiency of photovoltaic-thermal (PV/T) solar heat pump air-conditioning system reaches 10.4%, and can improve 23.8% in comparison with that of the conventional photovoltaic module, the mean COP of heat pump air-conditioning system may attain 2.88 and the water temperature in water heater can increase to 42 C. These results indicate that the photovoltaic-thermal solar heat pump air-conditioning system has better performances and can stably work. (author)

  16. Creation of Computational Benchmarks for LEU and MOX Fuel Assemblies Under Accident Conditions

    SciTech Connect

    Pavlovitchev, A M; Kalashnikov, A G; Kalugin, M A; Lazarenko, A P; Maiorov, L V; Sidorenko, V D

    1999-11-01

    The result of VVER-1000 computational benchmarks, calculations obtained with the use of various Russian codes (such as MCU-RFFI/A, TVS-M and WIMS-ABBN) are presented. List of benchmarks includes LEU and MOX cells with fresh and spent fuel under various conditions (for calculation of kinetic parameters, Doppler coefficient, reactivity effect of decreasing the water density). Calculations results are compared with each other and results of this comparison are discussed.

  17. Variation of atmospheric air pollution under conditions of rapid economic change—Estonia 1994-1999

    NASA Astrophysics Data System (ADS)

    Kimmel, V.; Tammet, H.; Truuts, T.

    Estonia is an example of a country with economy in transition whose atmospheric air pollution has been remarkably influenced by economic changes. During the period of 1994-1999 GDP increased by one-fourth, while agricultural production, electricity and heat production dropped by one-sixths during the studied period. These processes are reflected in the quantity of emissions and structure of air pollution. The study is based on the measurements of concentrations of pollutants at six Estonian Euroairnet monitoring stations—at three sites in the capital city and at three sites in remote areas. The pollutants concerned are the first-priority pollutants in the European Union legislation—nitrogen oxides, SO 2, O 3, particulate matter, and additionally CO. The study reveals that concentrations of gaseous pollutants in Estonia remain within the EU limit values except for ozone in remote areas. The main trend during the studied period was a significant, up to several times, decrease in concentrations of SO 2 and CO while the decrease of nitrogen oxides was less remarkable. The paper propose ratio of NO x/SO 2 as an index describing increasing transport loads and drop in use of sulphur-rich fuels—thus of structure of economy. The annual variation of pollutants is explained by seasonal variations of anthropogenic activity in conditions where local fuels are widely used for heating during winter. Air pollution in Estonian rural stations mostly originated from transboundary fluxes. The 1-3 day delay of the weekly minimum of pollutant concentrations and the wind roses allow to conclude that essential part of pollutants is imported from West Europe.

  18. Interaction of temperature, humidity, driver preferences, and refrigerant type on air conditioning compressor usage.

    PubMed

    Levine, C; Younglove, T; Barth, M

    2000-10-01

    Recent studies have shown large increases in vehicle emissions when the air conditioner (AC) compressor is engaged. Factors that affect the compressor-on percentage can have a significant impact on vehicle emissions and can also lead to prediction errors in current emissions models if not accounted for properly. During 1996 and 1997, the University of California, Riverside, College of Engineering-Center for Environmental Research and Technology (CE-CERT) conducted a vehicle activity study for the California Air Resources Board (CARB) in the Sacramento, CA, region. The vehicles were randomly selected from all registered vehicles in the region. As part of this study, ten vehicles were instrumented to collect AC compressor on/off data on a second-by-second basis in the summer of 1997. Temperature and humidity data were obtained and averaged on an hourly basis. The ten drivers were asked to complete a short survey about AC operational preferences. This paper examines the effects of temperature, humidity, refrigerant type, and driver preferences on air conditioning compressor activity. Overall, AC was in use in 69.1% of the trips monitored. The compressor was on an average of 64% of the time during the trips. The personal preference settings had a significant effect on the AC compressor-on percentage but did not interact with temperature. The refrigerant types, however, exhibited a differential response across temperature, which may necessitate separate modeling of the R12 refrigerant-equipped vehicles from the R134A-equipped vehicles. It should be noted that some older vehicles do get retrofitted with new compressors that use R134A; however, none of the vehicles in this study had been retrofitted.

  19. High Efficiency Liquid-Desiccant Regenerator for Air Conditioning and Industrial Drying

    SciTech Connect

    Andrew Lowenstein

    2005-12-19

    Over 2 quads of fossil fuels are used each year for moisture removal. This includes industrial and agricultural processes where feedstocks and final products must be dried, as well as comfort conditioning of indoor spaces where the control of humidity is essential to maintaining healthy, productive and comfortable working conditions. Desiccants, materials that have a high affinity for water vapor, can greatly reduce energy use for both drying and dehumidification. An opportunity exists to greatly improve the competitiveness of advanced liquid-desiccant systems by increasing the efficiency of their regenerators. It is common practice within the chemical process industry to use multiple stage boilers to improve the efficiency of thermal separation processes. The energy needed to regenerate a liquid desiccant, which is a thermal separation process, can also be reduced by using a multiple stage boiler. In this project, a two-stage regenerator was developed in which the first stage is a boiler and the second stage is a scavenging-air regenerator. The only energy input to this regenerator is the natural gas that fires the boiler. The steam produced in the boiler provides the thermal energy to run the second-stage scavenging-air regenerator. This two-stage regenerator is referred to as a 1?-effect regenerator. A model of the high-temperature stage of a 1?-effect regenerator for liquid desiccants was designed, built and successfully tested. At nominal operating conditions (i.e., 2.35 gpm of 36% lithium chloride solution, 307,000 Btu/h firing rate), the boiler removed 153 lb/h of water from the desiccant at a gas-based efficiency of 52.9 % (which corresponds to a COP of 0.95 when a scavenging-air regenerator is added). The steam leaving the boiler, when condensed, had a solids concentration of less than 10 ppm. This low level of solids in the condensate places an upper bound of about 6 lb per year for desiccant loss from the regenerator. This low loss will not create

  20. Effects of Surfactants and Synthetic Conditions on the Sizes and Self-Assembly of Monodisperse Iron Oxide Nanoparticles

    SciTech Connect

    Teng, X.; Yang, H.

    2004-02-17

    (B204)Monodisperse iron oxide nanoparticles made from the thermal decomposition of iron carbonyl in octyl ether in the presence of oleic and stearic acids have been examined under various reaction conditions. Monodisperse particles with diameters of 3, 5, 10, 16 and 25 nm have been made. Ostwald ripening could be the key reason for making monodisperse nanoparticles with diameters of up to 25 nm, above the largest sizes that have been reported so far for this class of materials. When stearic acid was used as surfactant, the reaction mixtures can reflux at a lower temperature than the reaction using oleic acid, and monodisperse 3 nm Fe2O3 particles can be made. By controlling the temperatures during the drop casting, different superstructures and superlattices can be created. The nanoparticles and their assembly have been characterized by transmission electron microscopy, electron diffraction, powder X-ray diffraction, and X-ray photoemission spectroscopy.

  1. The effect of the atmospheric condition on the extensive air shower analysis at the Telescope Array experiment

    SciTech Connect

    Kobayashi, Y.; Tsunesada, Y.; Tokuno, H.; Kakimoto, F.; Tomida, T.

    2011-09-22

    The accuracies in determination of air shower parameters such as longitudinal profiles or primary energies with the fluorescence detection technique are strongly dependent on atmospheric conditions of the molecular and aerosol components. Moreover, air fluorescence photon yield depends on the atmospheric density, and the transparency of the air for fluorescence photons depends on the atmospheric conditions from EAS to FDs. In this paper, we describe the atmospheric monitoring system in the Telescope Array (TA experiment), and the impact of the atmospheric conditions in air shower reconstructions. The systematic uncertainties of the determination of the primary cosmic ray energies and of the measurement of depth of maximum development (X{sub max}) of EASs due to atmospheric variance are evaluated by Monte Carlo simulation.

  2. Transcriptome assembly and microarray construction for Enchytraeus crypticus, a model oligochaete to assess stress response mechanisms derived from soil conditions

    PubMed Central

    2014-01-01

    Background The soil worm Enchytraeus crypticus (Oligochaeta) is an ecotoxicology model species that, until now, was without genome or transcriptome sequence information. The present research aims at studying the transcriptome of Enchytraeus crypticus, sampled from multiple test conditions, and the construction of a high-density microarray for functional genomic studies. Results Over 1.5 million cDNA sequence reads were obtained representing 645 million nucleotides. After assembly, 27,296 contigs and 87,686 singletons were obtained, from which 44% and 25% are annotated as protein-coding genes, respectively, sharing homology with other animal proteomes. Concerning assembly quality, 84% of the contig sequences contain an open reading frame with a start codon while E. crypticus homologs were identified for 92% of the core eukaryotic genes. Moreover, 65% and 77% of the singletons and contigs without known homologs, respectively, were shown to be transcribed in an independent microarray experiment. An Agilent 180 K microarray platform was designed and validated by hybridizing cDNA from 4 day zinc- exposed E. crypticus to the concentration corresponding to 50% reduction in reproduction after three weeks (EC50). Overall, 70% of all probes signaled expression above background levels (mean signal + 1x standard deviation). More specifically, the probes derived from contigs showed a wider range of average intensities when compared to probes derived from singletons. In total, 522 significantly differentially regulated transcripts were identified upon zinc exposure. Several significantly regulated genes exerted predicted functions (e.g. zinc efflux, zinc transport) associated with zinc stress. Unexpectedly, the microarray data suggest that zinc exposure alters retro transposon activity in the E. crypticus genome. Conclusion An initial investigation of the E. crypticus transcriptome including an associated microarray platform for future studies proves to be a valuable

  3. Removal of polycyclic aromatic hydrocarbons (PAHs) from industrial sludges in the ambient air conditions: automotive industry.

    PubMed

    Karaca, Gizem; Tasdemir, Yucel

    2013-01-01

    Removal of polycyclic aromatic hydrocarbons (PAHs) existed in automotive industry treatment sludge was examined by considering the effects of temperature, UV, titanium dioxide (TiO2) and diethyl amine (DEA) in different dosages (i.e., 5% and 20%) in this study. Application of TiO2 and DEA to the sludge samples in ambient environment was studied. Ten PAH (Σ10 PAH) compounds were targeted and their average value in the sludge was found to be 4480 ± 1450 ng/g dry matter (DM). Total PAH content of the sludge was reduced by 25% in the ambient air environment. Meteorological conditions, atmospheric deposition, evaporation and sunlight irradiation played an effective role in the variations in PAH levels during the tests carried out in ambient air environment. Moreover, it was observed that when the ring numbers of PAHs increased, their removal rates also increased. Total PAH level did not change with the addition of 5% DEA and only 10% decreased with 5% TiO2 addition. PAH removal ratios were 8% and 32% when DEA (20%) and TiO2 (20%) were added, respectively. It was concluded that DEA was a weak photo-sensitizer yet TiO2 was effective only at 20% dosage.

  4. The performance of a mobile air conditioning system with a water cooled condenser

    NASA Astrophysics Data System (ADS)

    Di Battista, Davide; Cipollone, Roberto

    2015-11-01

    Vehicle technological evolution lived, in recent years, a strong acceleration due to the increased awareness of environmental issues related to pollutants and climate altering emissions. This resulted in a series of international regulations on automotive sector which put technical challenges that must consider the engine and the vehicle as a global system, in order to improve the overall efficiency of the system. The air conditioning system of the cabin, for instance, is the one of the most important auxiliaries in a vehicle and requires significant powers. Its performances can be significantly improved if it is integrated within the engine cooling circuit, eventually modified with more temperature levels. In this paper, the Authors present a mathematical model of the A/C system, starting from its single components: compressors, condenser, flush valve and evaporator and a comparison between different refrigerant fluid. In particular, it is introduced the opportunity to have an A/C condenser cooled by a water circuit instead of the external air linked to the vehicle speed, as in the actual traditional configuration. The A/C condenser, in fact, could be housed on a low temperature water circuit, reducing the condensing temperature of the refrigeration cycle with a considerable efficiency increase.

  5. Heating, Ventilating, and Air-Conditioning: Recent Advances in Diagnostics and Controls to Improve Air-Handling System Performance

    NASA Astrophysics Data System (ADS)

    Wray, C. P.; Sherman, M. H.; Walker, I. S.; Dickerhoff, D. J.; Federspiel, C. C.

    2008-09-01

    The performance of air-handling systems in buildings needs to be improved. Many of the deficiencies result from myths and lore and a lack of understanding about the non-linear physical principles embedded in the associated technologies. By incorporating these principles, a few important efforts related to diagnostics and controls have already begun to solve some of the problems. This paper illustrates three novel solutions: one rapidly assesses duct leakage, the second configures ad hoc duct-static-pressure reset strategies, and the third identifies useful intermittent ventilation strategies. By highlighting these efforts, this paper seeks to stimulate new research and technology developments that could further improve air-handling systems.

  6. Development of High Speed Inverter Rotary Compressor for the Air-conditioning System

    NASA Astrophysics Data System (ADS)

    Kang, Seoung-Min; Yang, Eun-soo; Shin, Jin-Ung; Park, Joon-Hong; Lee, Se-Dong; Ha, Jong-Hun; Son, Young-Boo; Lee, Byeong-Chul

    2015-08-01

    In order to meet the various operating loads of an air-conditioning system, an inverter compressor with a wide operational range is necessary. One of the ways to achieve a wide operation range is to drive a small capacity compressor at high speed. Moreover, it is possible to maximize the efficiency in part-load operation condition close to actual operating conditions and to reduce the cost by compact design of a small capacity compressor. In addition, the shortage of maximum capacity, due to the small rated capacity, is covered through high speed operation. However, in general, if the compressor operates at high speed, problems occurs such as reduced efficiency due to friction, increased noise, increased amount of oil discharge and decreased durability of the main components. In order to solve these problems the following have been investigated: optimized dimension parameters of the compression chamber, enhanced shaft design and the structure for the reduction of oil discharge and noise at high speed operation. Finally the high speed inverter rotary compressor with high efficiency and more compact size has been developed as compared with the conventional rotary compressor.

  7. Study on application of capillary plane radiation air conditioning system based on the slope roof

    NASA Astrophysics Data System (ADS)

    Li, Y. G.; Wang, T. T.; Liu, X. L.; Dong, X. Z.

    2016-08-01

    In this paper, based on the principle of the capillary plane radiation air conditioning system, taking the slope roof as an example, the application of the capillary plane radiation airconditioning system is studied and analysed. Then the numerical solution of differential equations is obtained by the technology of CFD. Finally, we analyze the distribution of indoor temperature of the slope roof and the predicted mean votes (PMV) using Airpak simulation software by establishing a physical model. The results show that the PMV of different sections ranges from 0 to 2.5, which meets the requirement of the comfort. These provide a theoretical basis for application and promotion of capillary plane in the slope roof.

  8. New Automotive Air Conditioning System Simulation Tool Developed in MATLAB/Simulink

    SciTech Connect

    Kiss, T.; Chaney, L.; Meyer, J.

    2013-07-01

    Further improvements in vehicle fuel efficiency require accurate evaluation of the vehicle's transient total power requirement. When operated, the air conditioning (A/C) system is the largest auxiliary load on a vehicle; therefore, accurate evaluation of the load it places on the vehicle's engine and/or energy storage system is especially important. Vehicle simulation software, such as 'Autonomie,' has been used by OEMs to evaluate vehicles' energy performance. A transient A/C simulation tool incorporated into vehicle simulation models would also provide a tool for developing more efficient A/C systems through a thorough consideration of the transient A/C system performance. The dynamic system simulation software Matlab/Simulink was used to develop new and more efficient vehicle energy system controls. The various modeling methods used for the new simulation tool are described in detail. Comparison with measured data is provided to demonstrate the validity of the model.

  9. HVAC (heating, ventilation, air conditioning) literature in Japan: A critical review

    SciTech Connect

    Hane, G.J.

    1988-02-01

    Japanese businessmen in the heating, ventilation, air conditioning, and refrigeration (HVACandR) industry consider the monitoring of technical and market developments in the United States to be a normal part of their business. In contrast, efforts by US businessmen to monitor Japanese HVAC and R developments are poorly developed. To begin to redress this imbalance, this report establishes the groundwork for a more effective system for use in monitoring Japanese HVAC and R literature. Discussions of a review of the principal HVAC and R publications in Japan and descriptions of the type of information contained in each of those publications are included in this report. Since the Japanese HVAC and R literature is abundant, this report also provides practical suggestions on how a researcher or research manager can limit the monitoring effort to the publications and type of information that would most likely be of greatest value.

  10. Practical Fabry-Perot displacement interferometry in ambient air conditions with subnanometer accuracy

    NASA Astrophysics Data System (ADS)

    Voigt, Dirk; van de Nes, Arthur S.; van den Berg, Steven A.

    2014-07-01

    Fabry-Perot displacement interferometry (FPI) offers high sensitivity and resolution with direct traceability to optical frequency standards. FPI can provide means for demanding calibration tasks in precision engineering and high-tech systems. We report on our investigation of the measurement methodology applied to highest precision capacitive displacement sensors. We use a dedicated metrological FPI instrumentation that provides an actuated reference target with a relatively large traceable displacement stroke. The envisaged sub-nanometer measurement uncertainty seems very challenging under practical ambient atmospheric conditions and with the necessary sensor mounting components. In anticipation of these limitations, we propose a new FPI instrumental configuration with a very short cavity and discuss expected benefits, most importantly the very low sensitivity to air refractive index variations and the versatility for practical calibration purposes. We aim again for sub-nanometer measurement uncertainty and report on the status of the experimental set-up for this short cavity FPI.

  11. Study and Development of an Air Conditioning System Operating on a Magnetic Heat Pump Cycle

    NASA Technical Reports Server (NTRS)

    Wang, Pao-Lien

    1991-01-01

    This report describes the design of a laboratory scale demonstration prototype of an air conditioning system operating on a magnetic heat pump cycle. Design parameters were selected through studies performed by a Kennedy Space Center (KSC) System Simulation Computer Model. The heat pump consists of a rotor turning through four magnetic fields that are created by permanent magnets. Gadolinium was selected as the working material for this demonstration prototype. The rotor was designed to be constructed of flat parallel disks of gadolinium with very little space in between. The rotor rotates in an aluminum housing. The laboratory scale demonstration prototype is designed to provide a theoretical Carnot Cycle efficiency of 62 percent and a Coefficient of Performance of 16.55.

  12. Evaluation Framework and Analyses for Thermal Energy Storage Integrated with Packaged Air Conditioning

    SciTech Connect

    Kung, F.; Deru, M.; Bonnema, E.

    2013-10-01

    Few third-party guidance documents or tools are available for evaluating thermal energy storage (TES) integrated with packaged air conditioning (AC), as this type of TES is relatively new compared to TES integrated with chillers or hot water systems. To address this gap, researchers at the National Renewable Energy Laboratory conducted a project to improve the ability of potential technology adopters to evaluate TES technologies. Major project outcomes included: development of an evaluation framework to describe key metrics, methodologies, and issues to consider when assessing the performance of TES systems integrated with packaged AC; application of multiple concepts from the evaluation framework to analyze performance data from four demonstration sites; and production of a new simulation capability that enables modeling of TES integrated with packaged AC in EnergyPlus. This report includes the evaluation framework and analysis results from the project.

  13. Introduction Analysis of Refrigerating and Air-Conditioning Technologies in Micro Grid Type Food Industrial Park

    NASA Astrophysics Data System (ADS)

    Shimazaki, Yoichi

    The aim of this study was to evaluate the refrigerating and air-conditioning technologies in cases of introducing both cogeneration system and energy network in food industrial park. The energy data of 14 factories were classified into steam, hot water, heating, cooling, refrigerating, freezing and electric power by interviews. The author developed a micro grid model based on linear programming so as to minimize the total system costs. The industrial park was divided into the 2,500 square meter mesh in order to take steam transport into consideration. Four cases were investigated. It was found that the electric power driven freezer was introduced compared with the ammonia absorption freezer. The ammonia absorption freezer was introduced in the factory that there is a little steam demand and large freezing demand at the same time.

  14. Japanese power electronics inverter technology and its impact on the American air conditioning industry

    SciTech Connect

    Ushimaru, Kenji.

    1990-08-01

    Since 1983, technological advances and market growth of inverter- driven variable-speed heat pumps in Japan have been dramatic. The high level of market penetration was promoted by a combination of political, economic, and trade policies in Japan. A unique environment was created in which the leading domestic industries-- microprocessor manufacturing, compressors for air conditioning and refrigerators, and power electronic devices--were able to direct the development and market success of inverter-driven heat pumps. As a result, leading US variable-speed heat pump manufacturers should expect a challenge from the Japanese producers of power devices and microprocessors. Because of the vertically-integrated production structure in Japan, in contrast to the out-sourcing culture of the United States, price competition at the component level (such as inverters, sensors, and controls) may impact the structure of the industry more severely than final product sales. 54 refs., 47 figs., 1 tab.

  15. Japanese power electronics inverter technology and its impact on the American air conditioning industry

    NASA Astrophysics Data System (ADS)

    Ushimaru, Kenji

    1990-08-01

    Since 1983, technological advances and market growth of inverter-driven variable-speed heat pumps in Japan have been dramatic. The high level of market penetration was promoted by a combination of political, economic, and trade policies in Japan. A unique environment was created in which the leading domestic industries, microprocessor manufacturing, compressors for air conditioning and refrigerators, and power electronic devices, were able to direct the development and market success of inverter-driven heat pumps. As a result, leading U.S. variable-speed heat pump manufacturers should expect a challenge from the Japanese producers of power devices and microprocessors. Because of the vertically-integrated production structure in Japan, in contrast to the out-sourcing culture of the United States, price competition at the component level (such as inverters, sensors, and controls) may impact the structure of the industry more severely than final product sales.

  16. Feasibility of Remote Ischemic Peri-conditioning during Air Medical Transport of STEMI Patients.

    PubMed

    Martin-Gill, Christian; Wayne, Max; Guyette, Francis X; Olafiranye, Oladipupo; Toma, Catalin

    2016-01-01

    Remote ischemic peri-conditioning (RIPC) has gained interest as a means of reducing ischemic injury in patients with acute ST-elevation myocardial infarction (STEMI) who are undergoing emergent primary percutaneous coronary intervention (pPCI). We aimed to evaluate the feasibility, process, and patient-related factors related to the delivery of RIPC during air medical transport of STEMI patients to tertiary pPCI centers. We performed a retrospective review of procedural outcomes of a cohort of STEMI patients who received RIPC as part of a clinical protocol in a multi-state air medical service over 16 months (March 2013 to June 2014). Eligible patients were transported to two tertiary PCI centers and received up to four cycles of RIPC by inflating a blood pressure cuff on an upper arm to 200 mmHg for 5 minutes and subsequently deflating the cuff for 5 minutes. Data regarding feasibility, process variables, patient comfort, and occurrence of hypotension were obtained from prehospital records and prospectively completed quality improvement surveys. The primary outcome was whether at least 3 cycles of RIPC were completed by air medical transport crews prior to pPCI. Secondary outcomes included the number of cycles completed prior to pPCI, time spent with the patient prior to transport (bedside time), patient discomfort level, and incidence of hypotension (systolic blood pressure <90 mmHg) during the procedure. RIPC was initiated in 99 patients (91 interfacility, 8 scene transports) and 83 (83.3%) received 3 or 4 cycles of RIPC, delivered over 25-35 minutes. Median bedside time for interfacility transfers was 8 minutes (IQR 7, 10). More than half of patients reported no pain related to the procedure (N = 53, 53.3%), whereas 5 (5.1%) patients reported discomfort greater than 5 out of 10. Two patients developed hypotension while receiving RIPC and both had experienced hypotension prior to initiation of RIPC. RIPC is feasible and safe to implement for STEMI patients

  17. On Static Pressure Fluctuation between Sirocco Fan Blades in a Car Air-Conditioning System

    NASA Astrophysics Data System (ADS)

    Sakai, Yasuhiko; Kato, Takaaki; Moriguchi, Yuu; Sakai, Masaharu; Ito, Kouji; Mitsuishi, Yasushi; Nagata, Kouji; Kubo, Takashi

    In this study, special attention is directed to static pressure fluctuation in a sirocco fan for a car air-conditioning system, because it is expected that there is a close connection between the fluid noise and the pressure fluctuation. The final purpose of this study is to clarify the relationship between the static pressure fluctuation between fan blades and the sound noise emitted to the outside of the fan, and to develop an air-conditioning system with highly low noise level. For this purpose, first of all, a new micro probe for the measurement of static pressure fluctuation has been developed. This new micro probe is composed of an L-type static pressure tube (the outer diameter is 0.5 mm and the inner diameter is 0.34 mm) and a very small pressure transducer. This probe exhibits a flat frequency response until approximately 2,000 Hz, and it is set between the blades of the fan rotating at 1,500 rpm. The measurements of the static pressure fluctuation between the blades have been performed, and the intensity of sound source was quantified from the second derivative of the phase-averaged static pressure fluctuation signals on the basis of Ribner's formula (Ribner 1962). The experiments have been made in two different modes, i.e., the cooling mode (FACE MODE) and the heating mode (FOOT MODE). It is shown that the static pressure increases rapidly as the blade approaches to the nose of the casing. It is also found that the sound source for FACE MODE shows the larger value than that for FOOT MODE as a whole. In particular, the largest intensity of sound source is observed when the blade approaches to the nose. From these results, it is confirmed that the present new static pressure probe is useful to specify the distributions of sound source in a sirocco fan.

  18. Investigation of the air effect on the resonance frequency and damping of three small assembled structures using different adhesive materials (SU8 epoxy resin and compressed gold)

    NASA Astrophysics Data System (ADS)

    Nouira, H.; Foltête, E.; Hirsinger, L.; Ballandras, S.

    2008-06-01

    There has been growing interest in recent years in the understanding of microsystems and the mechanical properties essential for their design. In this context, an experimental technique is proposed to characterize the structures of small dimensions composed of both silicon and lithium niobate and assembled using three different adhesive materials (SU8 (5 and 1 µm) and compressed gold) surrounded by various ambient air pressure levels. Dynamic tests were performed on three different structures used for the manufacturing of a harvesting energy microconverter. The assembled structure is mounted on a support and excited by a white noise signal via an electromagnetic shaker. The dynamic responses are recorded by a Doppler laser vibrometer and the modal parameters (obtained from the dynamic response) are identified in order to determine their evolution when the ambient air pressure inside the vacuum chamber is changed. A nonlinear modal identification is then performed. It is based on the logarithmic decrement method applied in the time-frequency domain using a wavelet transform of the time responses. The evolution of the equivalent modal frequencies and damping of the assembled structure versus time and vibration magnitude are identified for several pressure values ranging from a secondary vacuum to atmospheric pressure.

  19. A study of energy use for ventilation and air-conditioning systems in Hong Kong

    NASA Astrophysics Data System (ADS)

    Yu, Chung Hoi Philip

    Most of the local modern buildings are high-rise with enclosed structure. Mechanical ventilation and air conditioning (MVAC) systems are installed for thermal comfort. Various types of MVAC systems found in Hong Kong were critically reviewed with comments on their characteristics in energy efficiency as well as application. The major design considerations were also discussed. Besides MVAC, other energy-consuming components in commercial buildings were also identified, such as lighting, lifts and escalators, office equipment, information technology facilities, etc. A practical approach has been adopted throughout this study in order that the end results will have pragmatic value to the heating, ventilating and air-conditioning (HVAC) industry in Hong Kong. Indoor Air Quality (IAQ) has become a major issue in commercial buildings worldwide including Hong Kong. Ventilation rate is no doubt a critical element in the design of HVAC systems, which can be realized more obviously in railway train compartments where the carbon dioxide level will be built up quickly when the compartments are crowded during rush hours. A study was carried out based on a simplified model using a train compartment that is equipped with an MVAC system. Overall Thermal Transfer Value (OTTV) is a single-value parameter for controlling building energy use and is relatively simple to implement legislatively. The local government has taken a first step in reacting to the worldwide concern of energy conservation and environmental protection since 1995. Different methods of OTTV calculation were studied and the computation results were compared. It gives a clear picture of the advantages and limitations for each method to the building designers. However, due to the limitations of using OTTV as the only parameter for building energy control, some new approaches to a total control of building energy use were discussed and they might be considered for future revision of the building energy codes in Hong

  20. AFM and EDX Study of Self Assembled Pt Nanostructures on PEDOT Thin Films under Ambient Conditions

    NASA Astrophysics Data System (ADS)

    Senevirathne, Indrajith; Mohney, Austin; Buchheit, Joshua; Goonewardene, Anura

    2011-03-01

    Noble metal nanostructure systems on conductive polymer thin films under ambient conditions are interesting due to their use in BioMEMS and hybrid systems further and considering the physics of the polymer - metal interactions The observed nanostructures have deformed spherical shape. The Pt was magnetron sputter deposited at RT (300K), PEDOT Baytron P 60nm thick, spin coated on glass slides cleaned with acetone and IPA. The system was studied using ambient IC mode Atomic Force Microscopy (AFM) for its structure. Elemental composition/distribution of the system was measured with Energy Dispersive X ray Spectroscopy (EDX). Pt nanostructures on the surface observed to be likely Volmer - Weber growth mode At Pt coverage of 120 ML, nanostructures had a mean diameter of 32 nm and mean height of 5 nm. When annealing at 15min at 473K systems changes to smaller nanostructures coexisting with bigger structures of mean diameter of 120 nm and mean height of 36 nm. Elemental/morphological variations when annealed at successively higher temperatures were also investigated. NSF Grant #: 0923047 and PASSHE FPDC (LOU # 2010-LHU-03).

  1. Acanthamoeba belonging to T3, T4, and T11: genotypes isolated from air-conditioning units in Santiago, Chile.

    PubMed

    Astorga, Berbeli; Lorenzo-Morales, Jacob; Martín-Navarro, Carmen M; Alarcón, Verónica; Moreno, Johanna; González, Ana C; Navarrete, Elizabeth; Piñero, José E; Valladares, Basilio

    2011-01-01

    Free-living amoebae (FLA) of the genus Acanthamoeba are widely distributed in the environment, in the air, soil, and water, and have also been isolated from air-conditioning units. The objective of this work was to investigate the presence of this genus of FLA in the air-conditioning equipment at the Institute of Public Health of Chile in Santiago, Chile. Water and air samples were collected from air-conditioning systems and were checked for the presence of Acanthamoeba spp. Positive samples were further classified at the genotype level after sequencing the highly variable diagnostic fragment 3 (DF3) region of the 18S rRNA gene. This is the first report of the T3, T4, and T11 genotypes of Acanthamoeba in air-conditioning units from Chile. Overall, the widespread distribution of potentially pathogenic Acanthamoeba strains in the studied source demands more awareness within the public and health professionals in Chile as this pathogen is emerging as a risk for human health worldwide.

  2. NREL's Energy-Saving Technology for Air Conditioning Cuts Peak Power Loads Without Using Harmful Refrigerants (Fact Sheet)

    SciTech Connect

    Not Available

    2012-07-01

    This fact sheet describes how the DEVAP air conditioner was invented, explains how the technology works, and why it won an R&D 100 Award. Desiccant-enhanced evaporative (DEVAP) air-conditioning will provide superior comfort for commercial buildings in any climate at a small fraction of the electricity costs of conventional air-conditioning equipment, releasing far less carbon dioxide and cutting costly peak electrical demand by an estimated 80%. Air conditioning currently consumes about 15% of the electricity generated in the United States and is a major contributor to peak electrical demand on hot summer days, which can lead to escalating power costs, brownouts, and rolling blackouts. DEVAP employs an innovative combination of air-cooling technologies to reduce energy use by up to 81%. DEVAP also shifts most of the energy needs to thermal energy sources, reducing annual electricity use by up to 90%. In doing so, DEVAP is estimated to cut peak electrical demand by nearly 80% in all climates. Widespread use of this cooling cycle would dramatically cut peak electrical loads throughout the country, saving billions of dollars in investments and operating costs for our nation's electrical utilities. Water is already used as a refrigerant in evaporative coolers, a common and widely used energy-saving technology for arid regions. The technology cools incoming hot, dry air by evaporating water into it. The energy absorbed by the water as it evaporates, known as the latent heat of vaporization, cools the air while humidifying it. However, evaporative coolers only function when the air is dry, and they deliver humid air that can lower the comfort level for building occupants. And even many dry climates like Phoenix, Arizona, have a humid season when evaporative cooling won't work well. DEVAP extends the applicability of evaporative cooling by first using a liquid desiccant-a water-absorbing material-to dry the air. The dry air is then passed to an indirect evaporative

  3. Adsorption at air-water and oil-water interfaces and self-assembly in aqueous solution of ethoxylated polysorbate nonionic surfactants.

    PubMed

    Penfold, Jeffrey; Thomas, Robert K; Li, Peixun X; Petkov, Jordan T; Tucker, Ian; Webster, John R P; Terry, Ann E

    2015-03-17

    The Tween nonionic surfactants are ethoxylated sorbitan esters, which have 20 ethylene oxide groups attached to the sorbitan headgroup and a single alkyl chain, lauryl, palmityl, stearyl, or oleyl. They are an important class of surfactants that are extensively used in emulsion and foam stabilization and in applications associated with foods, cosmetics and pharmaceuticals. A range of ethoxylated polysorbate surfactants, with differing degrees of ethoxylation from 3 to 50 ethylene oxide groups, have been synthesized and characterized by neutron reflection, small-angle neutron scattering, and surface tension. In conjunction with different alkyl chain groups, this provides the opportunity to modify their surface properties, their self-assembly in solution, and their interaction with macromolecules, such as proteins. Adsorption at the air-water and oil-water interfaces and solution self-assembly of the range of ethoxylated polysorbate surfactants synthesized are presented and discussed.

  4. A Database and Tool for Boundary Conditions for Regional Air Quality Modeling: Description and Evaluation

    EPA Science Inventory

    Transported air pollutants receive increasing attention as regulations tighten and global concentrations increase. The need to represent international transport in regional air quality assessments requires improved representation of boundary concentrations. Currently available ob...

  5. Modelica Library for Building Heating, Ventilation and Air-Conditioning Systems

    SciTech Connect

    Wetter, Michael

    2009-06-17

    This paper presents a freely available Modelica library for building heating, ventilation and air conditioning systems. The library is based on the Modelica.Fluid library. It has been developed to support research and development of integrated building energy and control systems. The primary applications are controls design, energy analysis and model-based operation. The library contains dynamic and steady-state component models that are applicable for analyzing fast transients when designing control algorithms and for conducting annual simulations when assessing energy performance. For most models, dimensional analysis is used to compute the performance for operating points that differ from nominal conditions. This allows parameterizing models in the absence of detailed geometrical information which is often impractical to obtain during the conceptual design phase of building systems. In the first part of this paper, the library architecture and the main classes are described. In the second part, an example is presented in which we implemented a model of a hydronic heating system with thermostatic radiator valves and thermal energy storage.

  6. Analyses of an air conditioning system with entropy generation minimization and entransy theory

    NASA Astrophysics Data System (ADS)

    Yan-Qiu, Wu; Li, Cai; Hong-Juan, Wu

    2016-06-01

    In this paper, based on the generalized heat transfer law, an air conditioning system is analyzed with the entropy generation minimization and the entransy theory. Taking the coefficient of performance (denoted as COP) and heat flow rate Q out which is released into the room as the optimization objectives, we discuss the applicabilities of the entropy generation minimization and entransy theory to the optimizations. Five numerical cases are presented. Combining the numerical results and theoretical analyses, we can conclude that the optimization applicabilities of the two theories are conditional. If Q out is the optimization objective, larger entransy increase rate always leads to larger Q out, while smaller entropy generation rate does not. If we take COP as the optimization objective, neither the entropy generation minimization nor the concept of entransy increase is always applicable. Furthermore, we find that the concept of entransy dissipation is not applicable for the discussed cases. Project supported by the Youth Programs of Chongqing Three Gorges University, China (Grant No. 13QN18).

  7. Analyses of an air conditioning system with entropy generation minimization and entransy theory

    NASA Astrophysics Data System (ADS)

    Yan-Qiu, Wu; Li, Cai; Hong-Juan, Wu

    2016-06-01

    In this paper, based on the generalized heat transfer law, an air conditioning system is analyzed with the entropy generation minimization and the entransy theory. Taking the coefficient of performance (denoted as COP) and heat flow rate Q out which is released into the room as the optimization objectives, we discuss the applicabilities of the entropy generation minimization and entransy theory to the optimizations. Five numerical cases are presented. Combining the numerical results and theoretical analyses, we can conclude that the optimization applicabilities of the two theories are conditional. If Q out is the optimization objective, larger entransy increase rate always leads to larger Q out, while smaller entropy generation rate does not. If we take COP as the optimization objective, neither the entropy generation minimization nor the concept of entransy increase is always applicable. Furthermore, we find that the concept of entransy dissipation is not applicable for the discussed cases. Project supported by the Youth Programs of Chongqing Three Gorges University, China (Grant No. 13QN18).

  8. Analytical study of a gas-fired adsorptive air-conditioning system

    SciTech Connect

    Poyelle, F.; Guilleminot, J.J.; Meunier, F.

    1996-11-01

    Adsorptive air conditioning represents a potential alternative to chlorofluorocarbon (CFC) systems. But to compete with other systems, adsorption systems must exhibit sufficient figures of merit and energetic densities. An analytical study to predict the overall heat transfer coefficient in an adsorber has been conducted and is presented here. This study, based on a method-of-moment analysis, shows the influence of three parameters limiting the heat transfer in adsorbent beds. Heat transfer in adsorbent beds has been intensified. Using new consolidated materials, the machine utilizes two uniform temperature adsorbent beds in a cycle that incorporates both heat and mass recovery. It uses a zeolite-water pair. It is designed to produce 3 kW of cooling. Expected cooling performances are 300 W/kg of adsorbent with a coefficient of performance (COP) close to 0.8 and a cycle time of 20 minutes. The thermal conditions used to test the cycle are: the heater, 220 C; the cooler, 40 C; and the evaporation temperature, 3 C.

  9. [Volatile organic compounds concentrations and sources inside new air-conditioned bus].

    PubMed

    You, Ke-Wei; Ge, Yun-Shan; Qian, Yi-Xin; Liu, Wei; Feng, Bo; Zhang, Yan-Ni; Ning, Zhan-Wu; Hu, Bin; Zhao, Shou-Tang

    2008-05-01

    The distributing profile and concentration level inside new air-conditioned buses with 53 seats have been determined using the method of thermal desorption-capillary GC/MS under vehicle static conditions. Compounds were identified from their mass spectral data by using US National Institute of Standards and Technology (NIST02). The total numbers of identified components were 33 inside buses, including alkenes (15,45.4%), aromatic compounds (9,27.3%), alcohols (4,12.1%), ketones (3,9.1%) and esters (2,6.1%), especially in the range of C6-C10. The top 5 compounds measured inside buses were decane (8.01 mg/m3), 3-methylhexane (7.10 mg/m3), heptane (5.10 mg/m3), isoheptane (4.20 mg/m3) and 1-Methyl-3-ethylbenzene (3.56 mg/m3), and total volatile organic compounds (TVOC) > 52.5 mg/m3. The main sources of in-vehicle hydrocarbons and aromatic compounds comes from cabin components and interior trim materials (e.g., sealants, carpets, adhesives, paints, leather, plastics, PU foam and PE foam) that may retain certain VOCs during manufacturing, and/or emit these compounds over an extended period of time from off-gassing, aging-related breakdown products, heating/cooling and so on.

  10. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... impractical, air flow of 2 mph or less will be allowed at 0 mph vehicle speed. (3) The fan air flow velocity vector perpendicular to the axial flow velocity vector shall be less than 10 percent of the mean velocity measured at fan speeds corresponding to vehicle speeds of 20 and 40 mph. (4)(i) Fan axial air flow...

  11. Legionella detection and subgrouping in water air-conditioning cooling tower systems in Kuwait.

    PubMed

    Al-Matawah, Qadreyah; Al-Zenki, Sameer; Al-Azmi, Ahmad; Al-Waalan, Tahani; Al-Salameen, Fadila; Hejji, Ahmad Ben

    2015-07-01

    The main aim of the study was to test for the presence of Legionnaires' disease-causing microorganisms in air-conditioned buildings in Kuwait using molecular technologies. For this purpose, 547 samples were collected from 38 cooling towers for the analysis of Legionella pneumophila. These samples included those from water (n = 178), air (n = 231), and swabs (n = 138). Out of the 547 samples, 226 (41%) samples were presumptive positive for L. pneumophila, with L. pneumophila viable counts in the positive water samples ranging from 1 to 88 CFU/ml. Of the Legionella culture-positive samples, 204 isolates were examined by latex agglutination. These isolates were predominately identified as L. pneumophila serogroup (sg) 2-14. Using the Dresden panel of monoclonal antibodies, 74 representatives isolates were further serogrouped. Results showed that 51% of the isolates belonged to serogroup 7 followed by 1 (18%) and 3 (18%). Serogroups 4 (4%) and 10 (7%) were isolated at a lower frequency, and two isolates could not be assigned to a serogroup. These results indicate the wide prevalence of L. pneumophila serogroup 7 as the predominant serogroup at the selected sampling sites. Furthermore, the 74 L. pneumophila (sg1 = 13; sg3 = 13; sg4 = 3; sg7 = 38; sg10 = 5; sgX = 2) isolates were genotyped using the seven gene protocol sequence-based typing (SBT) scheme developed by the European Working Group for Legionella Infections (EWGLI). The results show that Legionella isolates were discriminated into nine distinct sequence typing (ST) profiles, five of which were new to the SBT database of EWGLI. Additionally, all of the ST1 serogroup 1 isolates were of the OLDA/Oxford subgroup. These baseline data will form the basis for the development of a Legionella environmental surveillance program and used for future epidemiological investigations.

  12. Legionella detection and subgrouping in water air-conditioning cooling tower systems in Kuwait.

    PubMed

    Al-Matawah, Qadreyah; Al-Zenki, Sameer; Al-Azmi, Ahmad; Al-Waalan, Tahani; Al-Salameen, Fadila; Hejji, Ahmad Ben

    2015-07-01

    The main aim of the study was to test for the presence of Legionnaires' disease-causing microorganisms in air-conditioned buildings in Kuwait using molecular technologies. For this purpose, 547 samples were collected from 38 cooling towers for the analysis of Legionella pneumophila. These samples included those from water (n = 178), air (n = 231), and swabs (n = 138). Out of the 547 samples, 226 (41%) samples were presumptive positive for L. pneumophila, with L. pneumophila viable counts in the positive water samples ranging from 1 to 88 CFU/ml. Of the Legionella culture-positive samples, 204 isolates were examined by latex agglutination. These isolates were predominately identified as L. pneumophila serogroup (sg) 2-14. Using the Dresden panel of monoclonal antibodies, 74 representatives isolates were further serogrouped. Results showed that 51% of the isolates belonged to serogroup 7 followed by 1 (18%) and 3 (18%). Serogroups 4 (4%) and 10 (7%) were isolated at a lower frequency, and two isolates could not be assigned to a serogroup. These results indicate the wide prevalence of L. pneumophila serogroup 7 as the predominant serogroup at the selected sampling sites. Furthermore, the 74 L. pneumophila (sg1 = 13; sg3 = 13; sg4 = 3; sg7 = 38; sg10 = 5; sgX = 2) isolates were genotyped using the seven gene protocol sequence-based typing (SBT) scheme developed by the European Working Group for Legionella Infections (EWGLI). The results show that Legionella isolates were discriminated into nine distinct sequence typing (ST) profiles, five of which were new to the SBT database of EWGLI. Additionally, all of the ST1 serogroup 1 isolates were of the OLDA/Oxford subgroup. These baseline data will form the basis for the development of a Legionella environmental surveillance program and used for future epidemiological investigations. PMID:25701245

  13. Global warming impacts of ozone-safe refrigerants and refrigeration, heating, and air-conditioning technologies

    SciTech Connect

    Fischer, S.; Sand, J.; Baxter, V.

    1997-12-01

    International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming. Natural refrigerants are put forth as inherently superior to manufactured refrigerants because they have very low or zero global warming potentials (GWPs). Questions are being raised about whether or not these manufactured refrigerants, primarily hydrofluorocarbons (HFCs), should be regulated and perhaps phased out in much the same manner as CFCs and HCFCs. Several of the major applications of refrigerants are examined in this paper and the results of an analysis of their contributions to greenhouse warming are presented. Supermarket refrigeration is shown to be an application where alternative technologies have the potential to reduce emissions of greenhouse gases (GHG) significantly with no clear advantage to either natural or HFC refrigerants. Mixed results are presented for automobile air conditioners with opportunities to reduce GHG emissions dependent on climate and comfort criteria. GHG emissions for hermetic and factory built systems (i.e. household refrigerators/freezers, unitary equipment, chillers) are shown to be dominated by energy use with much greater potential for reduction through efficiency improvements than by selection of refrigerant. The results for refrigerators also illustrate that hydrocarbon and carbon dioxide blown foam insulation have lower overall effects on GHG emissions than HFC blown foams at the cost of increased energy use.

  14. HOW TO HEAT AND COOL A HOME WITH 400 CFM SUPPLY AIR AND KEEP THE DUCTS IN THE CONDITIONED SPACE

    SciTech Connect

    ANDREWS,J.W.

    1999-05-01

    A design strategy is presented that can enable a typical new home to be heated, cooled, and ventilated with less than 400 cfm of delivered air. The strategy has three major elements. First, peak cooling loads are minimized by using good available technologies for the envelope, with emphasis on minimizing heat gains through the windows. Second, the envelope is designed to have very low natural air leakage rates, such that all the ventilation air can be drawn in at one point and passed over the cooling coil before it is mixed with the house air. This permits a significant portion of the cooling load to be met at an air flow rate of {approximately}200 cubic feet per minute (cfm) per ton, compared with the typical 400 cfm per ton in standard air-conditioning systems. Third, by reducing the amount of supply air needed to meet the envelope loads, the required size of ductwork is reduced, making it easier to locate the ducts within the conditioned space. This reduces duct loads to zero, completing the three-part energy conserving strategy.

  15. Fuel Savings and Emission Reductions from Next-Generation Mobile Air Conditioning Technology in India

    SciTech Connect

    Chaney, L.; Thundiyil, K.; Andersen, S.; Chidambaram, S.; Abbi, Y. P.

    2007-01-01

    Up to 19.4% of vehicle fuel consumption in India is devoted to air conditioning (A/C). Indian A/C fuel consumption is almost four times the fuel penalty in the United States and close to six times that in the European Union because India's temperature and humidity are higher and because road congestion forces vehicles to operate inefficiently. Car A/C efficiency in India is an issue worthy of national attention considering the rate of increase of A/C penetration into the new car market, India's hot climatic conditions and high fuel costs. Car A/C systems originally posed an ozone layer depletion concern. Now that industrialized and many developing countries have moved away from ozone-depleting substances per Montreal Protocol obligations, car A/C impact on climate has captured the attention of policy makers and corporate leaders. Car A/C systems have a climate impact from potent global warming potential gas emissions and from fuel used to power the car A/Cs. This paper focuses on car A/C fuel consumption in the context of the rapidly expanding Indian car market and how new technological improvements can result in significant fuel savings and consequently, emission reductions. A 19.4% fuel penalty is associated with A/C use in the typical Indian passenger car. Car A/C fuel use and associated tailpipe emissions are strong functions of vehicle design, vehicle use, and climate conditions. Several techniques: reducing thermal load, improving vehicle design, improving occupants thermal comfort design, improving equipment, educating consumers on impacts of driver behaviour on MAC fuel use, and others - can lead to reduced A/C fuel consumption.

  16. Antioxidant and oxidative stress parameters in brain of Heteropneustes fossilis under air exposure condition; role of mitochondrial electron transport chain.

    PubMed

    Paital, Biswaranjan

    2013-09-01

    Many fishes are exposed to air in their natural habitat or during their commercial handling. In natural habitat or during commercial handling, the cat fish Heteropneustes fossilis is exposed to air for >24h. Data on its oxidative metabolism in the above condition are not available. Oxidative stress (OS) indices (lipid and protein oxidation), toxic reactive oxygen species (ROS: H2O2) generation, antioxidative status (levels of superoxide dismutase, catalase, glutathione peroxidase and reductase, ascorbic acid and non-protein sulfhydryl) and activities of electron transport chain (ETC) enzymes (complex I-IV) were investigated in brain tissue of H. fossilis under air exposure condition (0, 3, 6, 12 and 18 h at 25°C). Decreased activities of antioxidant (except catalase) and ETC enzymes (except complex II) with increased H2O2 and OS levels were observed in the tissue under water deprivation condition. Positive correlation was observed for complex II activity and non-protein thiol groups with time period of air exposure. The critical time period to induce OS and to reduce most of the studied antioxidant level in brain was found to be 3-6h air exposure. The data can be useful to minimize the stress generated during commercial handling of the live fishes those exposed to air in general and H. fossilis in particular.

  17. Dynamic, self-assembled aggregates of magnetized, millimeter-sized objects rotating at the liquid-air interface: macroscopic, two-dimensional classical artificial atoms and molecules.

    PubMed

    Grzybowski, B A; Jiang, X; Stone, H A; Whitesides, G M

    2001-07-01

    This paper describes self-assembly of millimeter-sized, magnetized disks floating on a liquid-air interface, and rotating under the influence of a rotating external magnetic field. Spinning of the disks results in hydrodynamic repulsion between them, while the rotating magnetic field produces an average confining potential acting on all disks. The interplay between hydrodynamic and magnetic interactions leads to the formation of patterns. Theoretical analysis of hydrodynamic and magnetic forces indicates that the interactions in this system are similar to those acting in systems of finite numbers of particles behaving classically ("classical artificial atoms"). Macroscopic artificial atoms and molecules are described, and the rules governing their morphologies outlined.

  18. Integrated Testing of a Carbon Dioxide Removal Assembly and a Temperature-Swing Adsorption Compressor for Closed-Loop Air Revitalization

    NASA Technical Reports Server (NTRS)

    Knox, J. C.; Mulloth, Lila; Frederick, Kenneth; Affleck, Dave

    2003-01-01

    Accumulation and subsequent compression of carbon dioxide that is removed from space cabin are two important processes involved in a closed-loop air revitalization scheme of the International Space Station (ISS). The carbon dioxide removal assembly (CDRA) of ISS currently operates in an open loop mode without a compressor. This paper describes the integrated test results of a flight-like CDRA and a temperature-swing adsorption compressor (TSAC) for carbon dioxide removal and compression. The paper provides details of the TSAC operation at various CO2 loadings and corresponding performance of CDRA.

  19. IMPACT OF HEATING AND AIR CONDITIONING SYSTEM OPERATION AND LEAKAGE ON VENTILATION AND INTERCOMPARTMENT TRANSPORT: STUDIES IN UNOCCUPIED AND OCCUPIED TENNESSEE VALLEY HOMES

    EPA Science Inventory

    Forced-air heating and air conditioning (HAC) systems caused an average and maximum increase in air infiltration rates of 1.8- and 4.3-fold, respectively, during brief whole-house studies of tracer gas decay In 39 occupied houses. An average Increase in air infiltration rate of 0...

  20. [Disinfectants and main sanitary and preventive measures for protection of ventilation and air-conditioning systems from Legionella contamination].

    PubMed

    Gerasimov, V N; Golov, E A; Khramov, M V; Diatlov, I A

    2008-01-01

    The study was devoted to selection and assessment of disinfecting preparations for prevention of contamination by Legionella. Using system of criteria for quality assessment of disinfectants, seven newdomestic ones belonging to quaternary ammonium compounds class or to oxygen-containing preparations and designed for disinfecting of air-conditioning and ventilation systems were selected. Antibacterial and disinfecting activities of working solutions of disinfectants were tested in laboratory on the test-surfaces and test-objects of premises' air-conditioning and ventilation systems contaminated with Legionella. High antimicrobial and disinfecting activity of new preparations "Dezactiv-M", "ExtraDez", "Emital-Garant", "Aquasept Plus", "Samarovka", "Freesept", and "Ecobreeze Oxy" during their exposure on objects and materials contaminated with Legionella was shown. Main sanitary and preventive measures for defending of air-conditioning and ventilation systems from contamination by Legionella species were presented.

  1. X-ray and neutron surface scattering for studying lipid/polymer assemblies at the air-liquid and solid-liquid interfaces.

    PubMed

    Majewski, J; Kuhl, T L; Wong, J Y; Smith, G S

    2000-09-01

    Simple mono- and bilayers, built of amphiphilic molecules and prepared at air-liquid or solid-liquid interfaces, can be used as models to study such effects as water penetration, hydrocarbon chain packing, and structural changes due to head group modification. In the paper, we will discuss neutron and X-ray reflectometry and grazing incidence X-ray diffraction techniques used to explore structures of such ultra-thin organic films in different environments. We will illustrate the use of these methods to characterize the morphologies of the following systems: (i) polyethylene glycol-modified distearoylphosphatidylethanolamine monolayers at air-liquid and solid-liquid interfaces; and (ii) assemblies of branched polyethyleneimine polymer and dimyristoylphophatidylcholine lipid at solid-liquid interfaces.

  2. Assessing the ability of mechanistic volatilization models to simulate soil surface conditions: a study with the Volt'Air model.

    PubMed

    Garcia, L; Bedos, C; Génermont, S; Braud, I; Cellier, P

    2011-09-01

    Ammonia and pesticide volatilization in the field is a surface phenomenon involving physical and chemical processes that depend on the soil surface temperature and water content. The water transfer, heat transfer and energy budget sub models of volatilization models are adapted from the most commonly accepted formalisms and parameterizations. They are less detailed than the dedicated models describing water and heat transfers and surface status. The aim of this work was to assess the ability of one of the available mechanistic volatilization models, Volt'Air, to accurately describe the pedo-climatic conditions of a soil surface at the required time and space resolution. The assessment involves: (i) a sensitivity analysis, (ii) an evaluation of Volt'Air outputs in the light of outputs from a reference Soil-Vegetation-Atmosphere Transfer model (SiSPAT) and three experimental datasets, and (iii) the study of three tests based on modifications of SiSPAT to establish the potential impact of the simplifying assumptions used in Volt'Air. The analysis confirmed that a 5 mm surface layer was well suited, and that Volt'Air surface temperature correlated well with the experimental measurements as well as with SiSPAT outputs. In terms of liquid water transfers, Volt'Air was overall consistent with SiSPAT, with discrepancies only during major rainfall events and dry weather conditions. The tests enabled us to identify the main source of the discrepancies between Volt'Air and SiSPAT: the lack of gaseous water transfer description in Volt'Air. They also helped to explain why neither Volt'Air nor SiSPAT was able to represent lower values of surface water content: current classical water retention and hydraulic conductivity models are not yet adapted to cases of very dry conditions. Given the outcomes of this study, we discuss to what extent the volatilization models can be improved and the questions they pose for current research in water transfer modeling and parameterization.

  3. Performance of a hydrogen burner to simulate air entering scramjet combustors. [simulation of total temperature, total pressure, and volume fraction of oxygen of air at flight conditions

    NASA Technical Reports Server (NTRS)

    Russin, W. R.

    1974-01-01

    Tests were conducted to determine the performance of a hydrogen burner used to produce a test gas that simulates air entering a scramjet combustor at various flight conditions. The test gas simulates air in that it duplicates the total temperature, total pressure, and the volume fraction of oxygen of air at flight conditions. The main objective of the tests was to determine the performance of the burner as a function of the effective exhaust port area. The conclusions were: (1) pressure oscillations of the chugging type were reduced in amplitude to plus or minus 2 percent of the mean pressure level by proper sizing of hydrogen, oxygen, and air injector flow areas; (2) combustion efficiency remained essentially constant as the exhaust port area was increased by a factor of 3.4; (3) the mean total temperature determined from integrating the exit radial gas property profiles was within plus or minus 5 percent of the theoretical bulk total temperature; (4) the measured exit total temperature profile had a local peak temperature more than 30 percent greater than the theoretical bulk total temperature; and (5) measured heat transfer to the burner liner was 75 percent of that predicted by theory based on a flat radial temperature profile.

  4. Energy Savings and Economics of Advanced Control Strategies for Packaged Air-Conditioning Units with Gas Heat

    SciTech Connect

    Wang, Weimin; Katipamula, Srinivas; Huang, Yunzhi; Brambley, Michael R.

    2011-12-31

    Pacific Northwest National Laboratory (PNNL) with funding from the U.S. Department of Energy's Building Technologies Program (BTP) evaluated a number of control strategies that can be implemented in a controller, to improve the operational efficiency of the packaged air conditioning units. The two primary objectives of this research project are: (1) determine the magnitude of energy savings achievable by retrofitting existing packaged air conditioning units with advanced control strategies not ordinarily used for packaged units and (2) estimating what the installed cost of a replacement control with the desired features should be in various regions of the U.S. This document reports results of the study.

  5. HFC-134a emissions from mobile air conditioning in China from 1995 to 2030

    NASA Astrophysics Data System (ADS)

    Su, Shenshen; Fang, Xuekun; Li, Li; Wu, Jing; Zhang, Jianbo; Xu, Weiguang; Hu, Jianxin

    2015-02-01

    Since 1995, 1,1,1,2-tetrafluoroethane (CH2FCF3, HFC-134a) has become the most important substitute of CFC-12 in mobile air conditioning (MAC) in China and MAC sector has dominated all the emissions of HFC-134a. In this study, we developed an accurate, updated and county-level inventory of the HFC-134a emissions from MAC in China for the period of 1995-2030 with an improved bottom-up method. Our estimation indicated that the total HFC-134a emissions kept growing at increase rates of ∼100% per year for 1995-2000 and ∼34% per year for 2001-2010. In 2010, HFC-134a emissions from MAC in China reached 16.7 Gg (10.5-22.7 Gg at 95% confidential interval), equivalent to 21.7 Tg CO2 (CO2-eq). Furthermore, the emissions in China estimated in this study accounted for 9.8% of global HFC-134a emissions and 29.0% of total emissions from Non-Annex_I countries in 2010. Due to the more advanced social-economic conditions and more intensive ownership of automobiles, greater HFC-134a were observed to come from big cities in East China. Under a Business-as-usual (BAU) Scenario, projected emissions will grow to 89.4 (57.9-123.9) Gg (about 75.3-161.1 Tg CO2-eq) in 2030, but under an Alternative Scenario, 88.6% of the projected emissions under BAU scenario could be curbed. Our estimation demonstrates huge emission mitigation potential of HFC-134a in China's MAC sector.

  6. Air Force F-16 Aircraft Engine Aerosol Emissions Under Cruise Altitude Conditions

    NASA Technical Reports Server (NTRS)

    Anderson, Bruce E.; Cofer, W. Randy, III; McDougal, David S.

    1999-01-01

    Selected results from the June 1997 Third Subsonic Assessment Near-Field Interactions Flight (SNIF-III) Experiment are documented. The primary objectives of the SNIF-III experiment were to determine the partitioning and abundance of sulfur species and to examine the formation and growth of aerosol particles in the exhaust of F-16 aircraft as a function of atmospheric and aircraft operating conditions and fuel sulfur concentration. This information is, in turn, being used to address questions regarding the fate of aircraft fuel sulfur impurities and to evaluate the potential of their oxidation products to perturb aerosol concentrations and surface areas in the upper troposphere. SNIF-III included participation of the Vermont and New Jersey Air National Guard F-16's as source aircraft and the Wallops Flight Facility T-39 Sabreliner as the sampling platform. F-16's were chosen as a source aircraft because they are powered by the modern F-100 Series 220 engine which is projected to be representative of future commercial aircraft engine technology. The T-39 instrument suite included sensors for measuring volatile and non-volatile condensation nuclei (CN), aerosol size distributions over the range from 0.1 to 3.0 (micro)m, 3-D winds, temperature, dewpoint, carbon dioxide (CO2), sulfur dioxide (SO2), sulfuric acid (H2SO4), and nitric acid (HNO3).

  7. Ultrafine particle removal by residential heating, ventilating, and air-conditioning filters.

    PubMed

    Stephens, B; Siegel, J A

    2013-12-01

    This work uses an in situ filter test method to measure the size-resolved removal efficiency of indoor-generated ultrafine particles (approximately 7-100 nm) for six new commercially available filters installed in a recirculating heating, ventilating, and air-conditioning (HVAC) system in an unoccupied test house. The fibrous HVAC filters were previously rated by the manufacturers according to ASHRAE Standard 52.2 and ranged from shallow (2.5 cm) fiberglass panel filters (MERV 4) to deep-bed (12.7 cm) electrostatically charged synthetic media filters (MERV 16). Measured removal efficiency ranged from 0 to 10% for most ultrafine particles (UFP) sizes with the lowest rated filters (MERV 4 and 6) to 60-80% for most UFP sizes with the highest rated filter (MERV 16). The deeper bed filters generally achieved higher removal efficiencies than the panel filters, while maintaining a low pressure drop and higher airflow rate in the operating HVAC system. Assuming constant efficiency, a modeling effort using these measured values for new filters and other inputs from real buildings shows that MERV 13-16 filters could reduce the indoor proportion of outdoor UFPs (in the absence of indoor sources) by as much as a factor of 2-3 in a typical single-family residence relative to the lowest efficiency filters, depending in part on particle size. PMID:23590456

  8. Experimental tests and predictive model of an adsorptive air conditioning unit

    SciTech Connect

    Poyelle, F.; Guilleminot, J.J.; Meunier, F.

    1999-01-01

    An adsorption air conditioning unit has been built operating with a heat nd mass recovery cycle and a zeolite-water pair. A new consolidated adsorbent composite with good heat transfer properties has been developed and implemented in the adsorber. At an evaporating temperature of 4 C, the experimental specific cooling power (SCP) of 97 W/kg achieved represents a real improvement in comparison with those measured with a packed bed technology. At this evaporating pressure, the mass transfer resistance controls the process. Therefore, at higher evaporating temperature a COP of 0.68 and a SCP of 135 W/kg were experimentally achieved. A new model has been developed to take into account the mass transfer limitations. The model has been validated and can predict the average pressure inside the adsorber and the components temperature of the unit. A new high conductive material with enhanced mass transfer properties has been developed. The predictive model shows that a SCP of 600 W/kg and a COP of 0.74 could be achieved with this new material.

  9. Experimental results and modeling tests of an adsorptive air-conditioning unit

    SciTech Connect

    Guilleminot, J.J.; Poyelle, F.; Meunier, F.

    1998-10-01

    Experimental tests have been performed on a zeolite-water adsorptive system suitable for air conditioning and consisting of two adsorbers filled with a consolidated composite made of zeolite mixed with a highly conductive matrix. This paper describes the experimental results of such a heat pump unit operating with a heat and mass recovery cycle. An important enhancement of the specific cooling power (SCP) has been achieved. At evaporating temperature T = 4 C, mass transfer resistance controls the process and limits the expected COP. Tests carried out at higher evaporating pressure make it possible to achieve the predicted COP and SCP. A predictive model developed and validated elsewhere in order to describe the temperature evolution of components and the heat and mass transfer in the adsorbers explains the mass transfer resistance in the adsorbent. Last, a new highly conductive adsorbent composite with good mass transfer properties is developed. The model is used to predict the performances of this new material. Very good SCP and COP can be achieved.

  10. Characterization of biological aerosol exposure risks from automobile air conditioning system.

    PubMed

    Li, Jing; Li, Mingzhen; Shen, Fangxia; Zou, Zhuanglei; Yao, Maosheng; Wu, Chang-yu

    2013-09-17

    Although use of automobile air conditioning (AC) was shown to reduce in-vehicle particle levels, the characterization of its microbial aerosol exposure risks is lacking. Here, both AC and engine filter dust samples were collected from 30 automobiles in four different geographical locations in China. Biological contents (bacteria, fungi, and endotoxin) were studied using culturing, high-throughput gene sequence, and Limulus amebocyte lysate (LAL) methods. In-vehicle viable bioaerosol concentrations were directly monitored using an ultraviolet aerodynamic particle sizer (UVAPS) before and after use of AC for 5, 10, and 15 min. Regardless of locations, the vehicle AC filter dusts were found to be laden with high levels of bacteria (up to 26,150 CFU/mg), fungi (up to 1287 CFU/mg), and endotoxin (up to 5527 EU/mg). More than 400 unique bacterial species, including human opportunistic pathogens, were detected in the filter dusts. In addition, allergenic fungal species were also found abundant. Surprisingly, unexpected fluorescent peaks around 2.5 μm were observed during the first 5 min use of AC, which was attributed to the reaerosolization of those filter-borne microbial agents. The information obtained here can assist in minimizing or preventing the respiratory allergy or infection risk from the use of automobile AC system.

  11. Ultrafine particle removal by residential heating, ventilating, and air-conditioning filters.

    PubMed

    Stephens, B; Siegel, J A

    2013-12-01

    This work uses an in situ filter test method to measure the size-resolved removal efficiency of indoor-generated ultrafine particles (approximately 7-100 nm) for six new commercially available filters installed in a recirculating heating, ventilating, and air-conditioning (HVAC) system in an unoccupied test house. The fibrous HVAC filters were previously rated by the manufacturers according to ASHRAE Standard 52.2 and ranged from shallow (2.5 cm) fiberglass panel filters (MERV 4) to deep-bed (12.7 cm) electrostatically charged synthetic media filters (MERV 16). Measured removal efficiency ranged from 0 to 10% for most ultrafine particles (UFP) sizes with the lowest rated filters (MERV 4 and 6) to 60-80% for most UFP sizes with the highest rated filter (MERV 16). The deeper bed filters generally achieved higher removal efficiencies than the panel filters, while maintaining a low pressure drop and higher airflow rate in the operating HVAC system. Assuming constant efficiency, a modeling effort using these measured values for new filters and other inputs from real buildings shows that MERV 13-16 filters could reduce the indoor proportion of outdoor UFPs (in the absence of indoor sources) by as much as a factor of 2-3 in a typical single-family residence relative to the lowest efficiency filters, depending in part on particle size.

  12. Gas Engine-Driven Heat Pump Chiller for Air-Conditioning and Hot Water Supply Systems

    NASA Astrophysics Data System (ADS)

    Fujita, Toshihiko; Mita, Nobuhiro; Moriyama, Tadashi; Hoshino, Norimasa; Kimura, Yoshihisa

    A gas engine-driven heat pump (GHP) uses a natural gas-or LPG-powered engine to drive the compressor in a vapor-compression refrigeration cycle. The GHP has the benefits of being able to use the fuel energy effectively by recovering waste heat from the engine jacket coolant and exhaust gas and also to keep high efficiency even at part-load operation by varying the engine speed with relative ease. Hence, energy-efficient heat source systems for air-conditioning and hot water supply may be constructed with GHP chillers in place of conventional electrical-driven heat pump chillers. GHPs will necessarily contribute to the peak shaving of electrical demand in summer. In this study, the performance characteristics of a 457kW GHP chiller have been investigated by a simulation model analysis, for both cooling and heating modes. From the results of the analysis, it has been found that the part-load characteristics of the GHP chiller are fairly well. The evaluation of the heat source systems using GHP chillers will be described in Part 2.

  13. Energy-Efficient Supermarket Heating, Ventilation, and Air Conditioning in Humid Climates in the United States

    SciTech Connect

    Clark, J.

    2015-03-01

    Supermarkets are energy-intensive buildings that consume the greatest amount of electricity per square foot of building of any building type in the United States and represent 5% of total U.S. commercial building primary energy use (EIA 2005). Refrigeration and heating, ventilation, and air-conditioning (HVAC) systems are responsible for a large proportion of supermarkets’ total energy use. These two systems sometimes work together and sometimes compete, but the performance of one system always affects the performance of the other. To better understand these challenges and opportunities, the Commercial Buildings team at the National Renewable Energy Laboratory investigated several of the most promising strategies for providing energy-efficient HVAC for supermarkets and quantified the resulting energy use and costs using detailed simulations. This research effort was conducted on behalf of the U.S. Department of Energy (DOE) Commercial Building Partnerships (CBP) (Baechler et al. 2012; Parrish et al. 2013; Antonopoulos et al. 2014; Hirsch et al. 2014). The goal of CBP was to reduce energy use in the commercial building sector by creating, testing, and validating design concepts on the pathway to net zero energy commercial buildings. Several CBP partners owned or operated buildings containing supermarkets and were interested in optimizing the energy efficiency of supermarket HVAC systems in hot-humid climates. These partners included Walmart, Target, Whole Foods Market, SUPERVALU, and the Defense Commissary Agency.

  14. Air Traffic Controllers' Control Strategies in the Terminal Area Under Off-Nominal Conditions

    NASA Technical Reports Server (NTRS)

    Martin, Lynne; Mercer, Joey; Callantine, Todd; Kupfer, Michael; Cabrall, Christopher

    2012-01-01

    A human-in-the-loop simulation investigated the robustness of a schedule-based terminal-area air traffic management concept, and its supporting controller tools, to off-nominal events - events that led to situations in which runway arrival schedules required adjustments and controllers could no longer use speed control alone to impose the necessary delays. The main research question was exploratory: to assess whether controllers could safely resolve and control the traffic during off-nominal events. A focus was the role of the supervisor - how he managed the schedules, how he assisted the controllers, what strategies he used, and which combinations of tools he used. Observations and questionnaire responses revealed supervisor strategies for resolving events followed a similar pattern: a standard approach specific to each type of event often resolved to a smooth conclusion. However, due to the range of factors influencing the event (e.g., environmental conditions, aircraft density on the schedule, etc.), sometimes the plan required revision and actions had a wide-ranging effect.

  15. Experimental evaluation of automotive air-conditioning using HFC-134a and HC-134a

    NASA Astrophysics Data System (ADS)

    Nasution, Henry; Zainudin, Muhammad Amir; Aziz, Azhar Abdul; Latiff, Zulkarnain Abdul; Perang, Mohd Rozi Mohd; Rahman, Abd Halim Abdul

    2012-06-01

    An experimental study to evaluate the energy consumption of an automotive air conditioning is presented. In this study, these refrigerants will be tested using the experimental rig which simulated the actual cars as a cabin complete with a cooling system component of the actual car that is as the blower, evaporator, condenser, radiators, electric motor, which acts as a vehicle engine, and then the electric motor will operate the compressor using a belt and pulley system, as well as to the alternator will recharge the battery. The compressor working with the fluids HFC-134a and HC-134a and has been tested varying the speed in the range 1000, 1500, 2000 and 2500 rpm. The measurements taken during the one hour experimental periods at 2-minutes interval times for temperature setpoint of 20°C with internal heat loads 0, 500, 700 and 1000 W. The final results of this study show an overall better energy consumption of the HFC-134a compared with the HC-134a.

  16. Monitoring biological impacts of space shuttle launches from Vandenberg Air Force Base: Establishment of baseline conditions

    NASA Technical Reports Server (NTRS)

    Schmaizer, Paul A.; Hinkle, C. Ross

    1987-01-01

    Space shuttle launches produce environmental impacts resulting from the formation of an exhaust cloud containing hydrogen chloride aerosols and aluminum oxide particulates. Studies have shown that most impacts occur near-field (within 1.5 km) of the launch site while deposition from launches occurs far-field (as distant as 22 km). In order to establish baseline conditions of vegetation and soils in the areas likely to be impacted by shuttle launches from Vandenberg Air Force Base (VAFB), vegetation and soils in the vicinity of Space Launch Complex-6 (SLC-6) were sampled and a vegetation map prepared. The areas likely to be impacted by launches were determined considering the structure of the launch complex, the prevailing winds, the terrain, and predictions of the Rocket Exhaust Effluent Diffusion Model (REEDM). Fifty vegetation transects were established and sampled in March 1986 and resampled in September 1986. A vegetation map was prepared for six Master Planning maps surrounding SLC-6 using LANDSAT Thematic Mapper imagery as well as color and color infrared aerial photography. Soil samples were collected form the 0 to 7.5 cm layer at all transects in the wet season and at a subsample of the transects in the dry season and analyzed for pH, organic matter, conductivity, cation exchange capacity, exchangeable Ca, Mg, Na, K, and Al, available NH3-N, PO4-P, Cu, Fe, Mn, Zn, and TKN.

  17. Rainforest air-conditioning: the moderating influence of epiphytes on the microclimate in tropical tree crowns

    NASA Astrophysics Data System (ADS)

    Stuntz, Sabine; Simon, Ulrich; Zotz, Gerhard

    2002-05-01

    Epiphytes are often assumed to influence the microclimatic conditions of the tree crowns that they inhabit. In order to quantify this notion, we measured the parameters "temperature" (of the substrate surface and the boundary layer of air above it), "evaporative drying rate" and "evapotranspiration" at various locations within tree crowns with differing epiphyte assemblages. The host tree species was Annona glabra, which was either populated by one of three epiphyte species ( Dimerandra emarginata, Tillandsia fasciculata, or Vriesea sanguinolenta) or was epiphyte-free. We found that during the hottest and driest time of day, microsites in the immediate proximity of epiphytes had significantly lower temperatures than epiphyte-bare locations within the same tree crown, even though the latter were also shaded by host tree foliage or branches. Moreover, water loss through evaporative drying at microsites adjacent to epiphytes was almost 20% lower than at exposed microsites. We also found that, over the course of several weeks, the evapotranspiration in tree crowns bearing epiphytes was significantly lower than in trees without epiphytes. Although the influence of epiphytes on temperature extremes and evaporation rates is relatively subtle, their mitigating effect could be of importance for small animals like arthropods inhabiting an environment as harsh and extreme as the tropical forest canopy.

  18. Solid-liquid hybrid assembly for ultrasonic elasticity measurements under hydrostatic conditions of up to 8 GPa in a Kawai-type multianvil apparatus

    NASA Astrophysics Data System (ADS)

    Song, M.; Yoneda, A.; Ito, E.

    2005-03-01

    A solid-liquid hybrid assembly has been designed for ultrasonic elasticity measurements of materials under hydrostatic conditions in a Kawai-type multianvil apparatus. In the assembly, a tungsten-carbide cubic anvil served as the buffer rod for the acoustic signals. The transducer and sample were mounted on two diagonally opposite truncated corners of the buffer-rod anvil. The sample was immersed in a liquid cell filled with a liquid pressure medium, a methanol-ethanol mixture (4:1 in volume), which produced hydrostatic conditions for the sample. The pressure was monitored with a bismuth pressure calibrant inside the liquid cell. Preliminary experiments using single-crystal MgO, polycrystal alumina, and silicate glass samples were successfully conducted up to 8GPa. This assembly is especially useful for precise elasticity measurements of single-crystal samples under hydrostatic compression.

  19. Stability of phosphonic self assembled monolayers (SAMs) on cobalt chromium (Co-Cr) alloy under oxidative conditions

    NASA Astrophysics Data System (ADS)

    Bhure, Rahul; Abdel-Fattah, Tarek M.; Bonner, Carl; Hall, Felicia; Mahapatro, Anil

    2011-04-01

    Cobalt chromium (Co-Cr) alloys have been widely used in the biomedical arena for cardiovascular, orthopedic and dental applications. Surface modification of the alloy allows us to tailor the interfacial properties to address critical challenges of Co-Cr alloy in medical applications. Self assembled monolayers (SAMs) of Octadecylphosphonic acid (ODPA) have been used to form thin films on the oxide layer of the Co-Cr alloy surface by solution deposition technique. The SAMs formed were investigated for their stability to oxidative conditions of ambient laboratory environment over periods of 1, 3, 7 and 14 days. The samples were then characterized for their stability using X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM) and contact angle measurements. Detailed high energy XPS elemental scans confirmed the presence of the phosphonic monolayer after oxidative exposure which suggested that the SAMs were firmly attached to the oxide layer of Co-Cr alloy. AFM images gave topographical data of the surface and showed islands of SAMs on Co-Cr alloy surface, before and after SAM formation and also over the duration of the oxidative exposure. Contact angle measurements confirmed the hydrophobicity of the surface over 14 days. Thus the SAMs were found to be stable for the duration of the study. These SAMs could be subsequently tailored by modifying the terminal functional groups and could be used for various potential biomedical applications such as drug delivery, biocompatibility and tissue integration.

  20. Variability and risk analysis of Hong Kong air quality based on Monsoon and El Niño conditions

    NASA Astrophysics Data System (ADS)

    Kim, Jong-Suk; Zhou, Wen; Cheung, Ho Nam; Chow, Chak Hang

    2013-03-01

    This study presents an exploratory analysis aimed at improving understanding of the variability of Hong Kong air quality associated with different climate conditions. Significantly negative correlations were found when Niño 3 led particulate matter ⩽10 μm PM10) and NO2 by 2-3 months over the Hong Kong territory, while the other pollutants (e.g., O3, SO2) showed modest correlations. A significant decreasing trend in visibility was observed during the autumn and winter, which has potential implications for the air-quality degradation and the endangerment of human health in Hong Kong. In an El Niño summer, the visibility was relatively better, while visibility in other seasons was diminished. On the other hand, in La Niña events, significant changes occurred in visibility in winter and autumn. Air pollution indices were less sensitive to the South China Summer Monsoon (SCSM), but a relatively high correlation existed between the East Asian Winter Monsoon (EAWM) and air pollutants. Rainfall was lower during most of the strong EAWM years compared to the weak years. This result suggests that the pollutants that accumulate in Hong Kong are not easy to wash out, so concentrations remain at a higher level. Finally, based on the conditional Air Pollution Index (API) risk assessment, site-specific vulnerabilities were analyzed to facilitate the development of the air-quality warning systems in Hong Kong.

  1. Fuel consumption and CO2/pollutant emissions of mobile air conditioning at fleet level - new data and model comparison.

    PubMed

    Weilenmann, Martin F; Alvarez, Robert; Keller, Mario

    2010-07-01

    Mobile air conditioning (MAC) systems are the second-largest energy consumers in cars after driving itself. While different measurement series are available to illustrate their behavior in hot ambient conditions, little data are available for lower temperatures. There are also no data available on diesel vehicles, despite these being quite common in Europe (up to 70% of the fleet in some countries). In the present study, six representative modern diesel passenger cars were tested. In combination with data from previous measurements on gasoline cars, a new model was developed - EEMAC = Empa Emission model for Mobile Air Conditioning systems - to predict emissions from air conditioning. The measurements obtained show that A/C activity still occurs at temperatures below the desired interior temperature. The EEMAC model was applied to the average meteorological year of a central European region and compared with the US EPA MOBILE6 model. As temperatures in central Europe are often below 20 degrees C (the point below which the two models differ), the overall results differ clearly. The estimated average annual CO(2) output according to EEMAC is six times higher than that of MOBILE6. EEMAC also indicates that around two-thirds of the fuel used for air conditioning could be saved by switching the MAC system off below 18 degrees C.

  2. Phase diagram, design of monolayer binary colloidal crystals, and their fabrication based on ethanol-assisted self-assembly at the air/water interface.

    PubMed

    Dai, Zhengfei; Li, Yue; Duan, Guotao; Jia, Lichao; Cai, Weiping

    2012-08-28

    Flexible structural design and accurate controlled fabrication with structural tunability according to need for binary or multicomponent colloidal crystals have been expected. However, it is still a challenge. In this work, the phase diagram of monolayer binary colloidal crystals (bCCs) is established on the assumption that both large and small polystyrene (PS) colloidal spheres can stay at the air/water interface, and the range diagram for the size ratio and number ratio of small to large colloidal spheres is presented. From this phase diagram, combining the range diagram, we can design and relatively accurately control fabrication of the bCCs with specific structures (or patterns) according to need, including single or mixed patterns with the given relative content. Further, a simple and facile approach is presented to fabricate large-area (more than 10 cm(2)) monolayer bCCs without any surfactants, using differently sized PS spheres, based on ethanol-assisted self-assembly at the air/water interface. bCCs with different patterns and stoichiometries are thus designed from the established phase diagram and then successfully fabricated based on the volume ratios (V(S/L)) of the small to large PS suspensions using the presented colloidal self-assembling method. Interestingly, these monolayer bCCs can be transferred to any desired substrates using water as the medium. This study allows us to design desired patterns of monolayer bCCs and to more accurately control their structures with the used V(S/L).

  3. Spring photosynthetic recovery of boreal Norway spruce under conditions of elevated [CO(2)] and air temperature.

    PubMed

    Wallin, Göran; Hall, Marianne; Slaney, Michelle; Räntfors, Mats; Medhurst, Jane; Linder, Sune

    2013-11-01

    Accumulated carbon uptake, apparent quantum yield (AQY) and light-saturated net CO2 assimilation (Asat) were used to assess the responses of photosynthesis to environmental conditions during spring for three consecutive years. Whole-tree chambers were used to expose 40-year-old field-grown Norway spruce trees in northern Sweden to an elevated atmospheric CO2 concentration, [CO2], of 700 μmol CO2 mol(-1) (CE) and an air temperature (T) between 2.8 and 5.6 °C above ambient T (TE), during summer and winter. Net shoot CO2 exchange (Anet) was measured continuously on 1-year-old shoots and was used to calculate the accumulated carbon uptake and daily Asat and AQY. The accumulated carbon uptake, from 1 March to 30 June, was stimulated by 33, 44 and 61% when trees were exposed to CE, TE, and CE and TE combined, respectively. Air temperature strongly influenced the timing and extent of photosynthetic recovery expressed as AQY and Asat during the spring. Under elevated T (TE), the recovery of AQY and Asat commenced ∼10 days earlier and the activity of these parameters was significantly higher throughout the recovery period. In the absence of frost events, the photosynthetic recovery period was less than a week. However, frost events during spring slowed recovery so that full recovery could take up to 60 days to complete. Elevated [CO2] stimulated AQY and Asat on average by ∼10 and ∼50%, respectively, throughout the recovery period, but had minimal or no effect on the onset and length of the photosynthetic recovery period during the spring. However, AQY, Asat and Anet all recovered at significantly higher T (average +2.2 °C) in TE than in TA, possibly caused by acclimation or by shorter days and lower light levels during the early part of the recovery in TE compared with TA. The results suggest that predicted future climate changes will cause prominent stimulation of photosynthetic CO2 uptake in boreal Norway spruce forest during spring, mainly caused by elevated T

  4. Spring photosynthetic recovery of boreal Norway spruce under conditions of elevated [CO(2)] and air temperature.

    PubMed

    Wallin, Göran; Hall, Marianne; Slaney, Michelle; Räntfors, Mats; Medhurst, Jane; Linder, Sune

    2013-11-01

    Accumulated carbon uptake, apparent quantum yield (AQY) and light-saturated net CO2 assimilation (Asat) were used to assess the responses of photosynthesis to environmental conditions during spring for three consecutive years. Whole-tree chambers were used to expose 40-year-old field-grown Norway spruce trees in northern Sweden to an elevated atmospheric CO2 concentration, [CO2], of 700 μmol CO2 mol(-1) (CE) and an air temperature (T) between 2.8 and 5.6 °C above ambient T (TE), during summer and winter. Net shoot CO2 exchange (Anet) was measured continuously on 1-year-old shoots and was used to calculate the accumulated carbon uptake and daily Asat and AQY. The accumulated carbon uptake, from 1 March to 30 June, was stimulated by 33, 44 and 61% when trees were exposed to CE, TE, and CE and TE combined, respectively. Air temperature strongly influenced the timing and extent of photosynthetic recovery expressed as AQY and Asat during the spring. Under elevated T (TE), the recovery of AQY and Asat commenced ∼10 days earlier and the activity of these parameters was significantly higher throughout the recovery period. In the absence of frost events, the photosynthetic recovery period was less than a week. However, frost events during spring slowed recovery so that full recovery could take up to 60 days to complete. Elevated [CO2] stimulated AQY and Asat on average by ∼10 and ∼50%, respectively, throughout the recovery period, but had minimal or no effect on the onset and length of the photosynthetic recovery period during the spring. However, AQY, Asat and Anet all recovered at significantly higher T (average +2.2 °C) in TE than in TA, possibly caused by acclimation or by shorter days and lower light levels during the early part of the recovery in TE compared with TA. The results suggest that predicted future climate changes will cause prominent stimulation of photosynthetic CO2 uptake in boreal Norway spruce forest during spring, mainly caused by elevated T

  5. 40 CFR 1066.845 - AC17 air conditioning efficiency test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... voluntary procedure for measuring the net impact of air conditioner operation on CO2 emissions. See 40 CFR... solar heating is disabled for certain test intervals as described in this section. (d) Interior air... tests according to 40 CFR 86.132-00(a) through (g). If the vehicle has been tested within the last...

  6. Physical conditions for trapping air by a microtrichia-covered insect cuticle during temporary submersion

    NASA Astrophysics Data System (ADS)

    Neumann, Dietrich; Woermann, Dietrich

    2009-08-01

    The intertidal midge Clunio, which reproduces on exposed rocky seashores, becomes enclosed in an irregularly shaped air bubble during short submersion by incoming waves. This water-repellent property of Clunio’s cuticle is caused by a complete cover of hydrophobic microtrichia offering an effective surf tolerance. These microtrichia not only trap a thin air layer above the cuticle but also maintain a larger air bubble between the insect’s ventral side and legs. The effectiveness of the water repellence was quantitatively characterised on the basis of a known model (Crisp and Thorpe, Discuss Faraday Soc 3:210-220, 1948). The parameters of the model are the contact angle θ (>90°) at the contact line of air/water/microtrichia and the distance between individual microtrichia and their radius. When the microtrichia are 1.1 μm apart and have a radius of 0.1 μm and an estimated contact angle θ of 140°, the air layer is stable against hydrostatic pressures of up to 3 m water column. As shown by a modified version of the model, considerably larger air bubbles can be trapped by the microtrichia cover of the legs up to distances of 0.5 mm from the body. The widely spaced (about 8 μm apart) and longer setae of Clunio are not involved in the formation of air layers and air bubble.

  7. Indoor weather related to the energy consumption of air conditioned classroom: Monitoring system for energy efficient building plan

    NASA Astrophysics Data System (ADS)

    Rattanongphisat, W.; Suwannakom, A.; Harfield, A.

    2016-08-01

    The current research aims to investigate the relation of indoor weather to energy consumption of air conditioned classroom by design and construct the indoor weather and energy monitoring systems. In this research, a combined temperature and humidity sensor in conjunction with a microcontroller was constructed for the indoor weather monitoring system. The wire sensor network for the temperature-humidity sensor nodes is the Controller Area Network (CAN). Another part is using a nonintrusive method where a wireless current transformer sending the signal to the data collection box then transmitted by the radio frequency to the computer where the Ethernet application software was installed for the energy monitoring system. The results show that the setting air temperature, outdoor ambient temperature and operating time impact to the energy consumption of the air conditioned classroom.

  8. Relationship between the merit factor of thermoelectric materials and the air conditioning unit of urban electric cars

    NASA Astrophysics Data System (ADS)

    Buffet, Jean

    1994-08-01

    The main benefit of electric cars is to reduce air pollution in cities that is thus desirable to equip them with non polluting air conditioning units and this rules out frigorific compressors operating with CFC. The planned replacement of CFC by HFC is at best an interim solution. The best solution is certainly to use thermoelectric air conditioning units, which are inherently pollution-free. However, these have a fairly low COPF when compared to traditional compressor units. We study the relationship between the cooling of the interior of urban electric cars and the merit factor of the thermoelectric material in their Peltier unit. This should help provide concrete target properties of future T E materials.

  9. Relationship between the merit factor of thermoelectric materials and the air conditioning unit of urban electric cars

    SciTech Connect

    Buffet, J.

    1994-08-10

    The main benefit of electric cars is to reduce air pollution in cities that is thus desirable to equip them with non polluting air conditioning units and this rules out frigorific compressors operating with CFC. The planned replacement of CFC by HFC is at best an interim solution. The best solution is certainly to use thermoelectric air conditioning units, which are inherently pollution-free. However, these have a fairly low COPF when compared to traditional compressor units. We study the relationship between the cooling of the interior of urban electric cars and the merit factor of the thermoelectric material in their Peltier unit. This should help provide concrete target properties of future T E materials. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  10. Effectiveness of photocatalytic filter for removing volatile organic compounds in the heating, ventilation, and air conditioning system.

    PubMed

    Yu, Kuo-Pin; Lee, Grace Whei-May; Huang, Wei-Ming; Wu, Chih-Cheng; Lou, Chia-ling; Yang, Shinhao

    2006-05-01

    Nowadays, the heating, ventilation, and air conditioning (HVAC) system has been an important facility for maintaining indoor air quality. However, the primary function of typical HVAC systems is to control the temperature and humidity of the supply air. Most indoor air pollutants, such as volatile organic compounds (VOCs), cannot be removed by typical HVAC systems. Thus, some air handling units for removing VOCs should be added in typical HVAC systems. Among all of the air cleaning techniques used to remove indoor VOCs, photocatalytic oxidation is an attractive alternative technique for indoor air purification and deodorization. The objective of this research is to investigate the VOC removal efficiency of the photocatalytic filter in a HVAC system. Toluene and formaldehyde were chosen as the target pollutants. The experiments were conducted in a stainless steel chamber equipped with a simplified HVAC system. A mechanical filter coated with Degussa P25 titania photocatalyst and two commercial photocatalytic filters were used as the photocatalytic filters in this simplified HVAC system. The total air change rates were controlled at 0.5, 0.75, 1, 1.25, and 1.5 hr(-1), and the relative humidity (RH) was controlled at 30%, 50%, and 70%. The ultraviolet lamp used was a 4-W, ultraviolet-C (central wavelength at 254 nm) strip light bulb. The first-order decay constant of toluene and formaldehyde found in this study ranged from 0.381 to 1.01 hr(-1) under different total air change rates, from 0.34 to 0.433 hr(-1) under different RH, and from 0.381 to 0.433 hr(-1) for different photocatalytic filters.

  11. Military Curricula for Vocational & Technical Education. Refrigeration & Air Conditioning Specialist, Blocks III-V, 11-7.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This plan of instruction, study guides, and workbooks for a secondary-postsecondary-level course in refrigeration and air conditioning are one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. It is the second section of a three-part course (see…

  12. Effects of air velocity on laying hen production from 24 to 27 weeks under simulated evaporatively cooled conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal conditions play a major role in production efficiency in commercial poultry production. Mitigation of thermal stress can improve productivity, but must be achieved economically. Weather and system design can limit effectiveness of evaporative cooling and increased air movement has been sho...

  13. Articulated, Performance-Based Instruction Objectives Guide for Air Conditioning, Refrigeration, and Heating. Volume II (Second Year).

    ERIC Educational Resources Information Center

    Henderson, William Edward, Jr., Ed.

    This articulation guide contains 17 units of instruction for the second year of a two-year vocational program designed to prepare the high school graduate to install, maintain, and repair various types of residential and commercial heating, air conditioning, and refrigeration equipment. The units are designed to help the student to expand and…

  14. FAULT TREE ANALYSIS FOR EXPOSURE TO REFRIGERANTS USED FOR AUTOMOTIVE AIR CONDITIONING IN THE U.S.

    EPA Science Inventory

    A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servic...

  15. Space Station Freedom seal leakage rate analysis and testing summary: Air leaks in ambient versus vacuum exit conditions

    NASA Technical Reports Server (NTRS)

    Rodriguez, P. I.; Markovitch, R.

    1992-01-01

    This report is intended to reveal the apparent relationship of air seal leakage rates between 2 atmospheres (atm) to 1 atm and 1 atm to vacuum conditions. Gas dynamics analysis is provided as well as data summarizing the MSFC test report, 'Space Station Freedom (S.S. Freedom) Seal Flaw Study With Delta Pressure Leak Rate Comparison Test Report'.

  16. Competency Index for Air Conditioning and Refrigeration Programs in Missouri. A Crosswalk of Selected Instructional Materials against Missouri's Competency Profile.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Instructional Materials Lab.

    This index was developed to help air conditioning and refrigeration instructors in Missouri use existing instructional materials and keep track of student progress on the VAMS system. The list was compiled by a committee of instructors who selected appropriate references and identified areas that pertained to Missouri competencies. The index lists…

  17. Multimedia Approach to Self-Paced Individualized Instruction in Air Conditioning, Refrigeration and Heating and Other Vocational Programs. Final Report.

    ERIC Educational Resources Information Center

    Oil Belt Vocational Technical School, El Dorado, AR.

    A multimedia, self-paced, individualized instructional program was designed to meet the needs of students in air conditioning, refrigeration, and heating programs at Oil Belt Vocational Technical School (Arkansas). The multimedia approach provided for video-based presentations to meet the needs for visual contact with the classroom and for…

  18. Commercialization of air conditioning heat pump/water heater. Final technical report, Volume 1: Transmittal documents; Executive summary; Project summary

    SciTech Connect

    1996-01-30

    This is the final technical report on a commercialization project for an air conditioning heat pump water heater. The objective of the project was to produce a saleable system which would be economically competitive with natural gas and cost effective with regard to initial cost versus annual operating costs. The development and commercialization of the system is described.

  19. Photosynthesis, transpiration and water use efficiencies of a plant canopy and plant leaves under restricted air current conditions

    NASA Astrophysics Data System (ADS)

    Kitaya, Yoshiaki; Shibuya, Toshio; Tsuruyama, Joshin

    A fundamental study was conducted to obtain the knowledge for culturing plants and exchanging gases with plants under restricted air circulation conditions in space agriculture. The effects of air velocities less than 1.3 m s-1 on net photosynthetic rates (Pn), transpiration rates (Tr) and Pn/Tr, water use efficiencies (WUE), of a canopy of cucumber seedlings and of single leaves of cucumber, sweet potato and barley were assessed with assimilation chamber methods in ground based experiments. The cucumber seedling canopy, which had a LAI of 1.4 and height of 0.1 m, was set in a wind tunnel installed in a plant canopy assimilation chamber. Each of the attached single leaves was set in a leaf assimilation chamber. The Pn and Tr of the plant canopy increased to 1.2 and 2.8 times, respectively, and WUE decreased to 0.4 times with increasing the air velocity from 0.02 to 1.3 m s-1. The Pn and Tr of the single leaves of all the species increased by 1.3-1.7 and 1.9-2.2 times, respectively, and WUE decreased to 0.6-0.8 times as the air velocity increased from 0.05 to 0.8 m s-1. The effect of air velocity was more significant on Tr than on Pn and thus WUE decreased with increasing air velocity in both the plant canopy and the individual leaves. The leaf boundary layer resistance was approximately proportional to the minus 1/3 power of the air velocity. Stomatal resistance was almost constant during the experiment. The CO2 concentrations in the sub-stomatal cavity in leaves of cucumber, sweet potato and barley, respectively, were 43, 31 and 58 mmol mol-1 lower at the air velocity of 0.05 m s-1 than at the air velocity of 0.8 m s-1, while the water vapor pressure in the sub-stomatal cavity was constant. We concluded that the change in the CO2 concentration in the sub-stomatal cavity was a cause of the different effect of the air velocity on Pn and Tr, and thus on WUE. The phenomenon will be more remarkable under restricted air convection conditions at lower gravity in space.

  20. [Sanitary conditions of community dining halls in greater Buenos Aires, Argentina].

    PubMed

    Arango, J; Agostini, A; Silvestre, A; Yaafar, M; López, C; Fishmann, H

    1997-10-01

    Because of the importance of food safety for public health, a study was done to determine the microbiologic quality of foods provided to patrons of community dining halls in greater Buenos Aires, Argentina. The study was descriptive and was conducted in three municipalities with intermediate or high poverty indices; a sample of 52 dining halls was selected randomly from those municipalities. Information was collected from April 1994 through April 1995 by means of surveys, direct observations, and microbiologic analyses of the water and food served. Water and food analysis followed the recommendations of the Argentine Food Code and the International Commission on Microbiologic Specifications for Foods, respectively. The results were interpreted according to the values for cooked foods agreed upon by the Working Group on Food Monitoring. The microbiologic analysis revealed that 28 (54%) of the dining halls had food or water of inadequate quality and 11 (21%) had inadequacies in both. Bacillus cereus was the most commonly found pathogenic bacterium in the food samples analyzed. The factors that were significantly associated with unsatisfactory microbiologic conditions in the food and water were lack of disinfection of the water (P = 0.009), lack of hygiene in the environment (P = 0.03), the presence of rodents and insects (P = 0.05), the supply system for raw materials (P = 0.01), and a relatively small number of users, i.e., fewer than 100 (P = 0.0008). It was concluded that water disinfection and general clean-up of the dining halls were measures that could be put in place by providing education in the areas of hygiene and food handling to supervisors and employees. The results obtained also indicate the need to include a food safety evaluation among the general evaluation criteria for food assistance programs. PMID:9445768

  1. Anatomical Details of the Rabbit Nasal Passages and Their Implications in Breathing, Air Conditioning, and Olfaction.

    PubMed

    Xi, Jinxiang; Si, Xiuhua A; Kim, Jongwon; Zhang, Yu; Jacob, Richard E; Kabilan, Senthil; Corley, Richard A

    2016-07-01

    The rabbit is commonly used as a laboratory animal for inhalation toxicology tests and detail knowledge of the rabbit airway morphometry is needed for outcome analysis or theoretical modeling. The objective of this study is to quantify the morphometric dimension of the nasal airway of a New Zealand white rabbit and to relate the morphology and functions through analytical and computational methods. Images of high-resolution MRI scans of the rabbit were processed to measure the axial distribution of the cross-sectional areas, perimeter, and complexity level. The lateral recess, which has functions other than respiration or olfaction, was isolated from the nasal airway and its dimension was quantified separately. A low Reynolds number turbulence model was implemented to simulate the airflow, heat transfer, vapor transport, and wall shear stress. Results of this study provide detailed morphological information of the rabbit that can be used in the studies of olfaction, inhalation toxicology, drug delivery, and physiology-based pharmacokinetics modeling. For the first time, we reported a spiral nasal vestibule that splits into three paths leading to the dorsal meatus, maxilloturbinate, and ventral meatus, respectively. Both non-dimensional functional analysis and CFD simulations suggested that the airflow in the rabbit nose is laminar and the unsteady effect is only significantly during sniffing. Due to the large surface-to-volume ratio, the maxilloturbinate is highly effective in warming and moistening the inhaled air to body conditions. The unique anatomical structure and respiratory airflow pattern may have important implications for designing new odorant detectors or electronic noses. Anat Rec, 299:853-868, 2016. © 2016 Wiley Periodicals, Inc.

  2. Anatomical Details of the Rabbit Nasal Passages and Their Implications in Breathing, Air Conditioning, and Olfaction.

    PubMed

    Xi, Jinxiang; Si, Xiuhua A; Kim, Jongwon; Zhang, Yu; Jacob, Richard E; Kabilan, Senthil; Corley, Richard A

    2016-07-01

    The rabbit is commonly used as a laboratory animal for inhalation toxicology tests and detail knowledge of the rabbit airway morphometry is needed for outcome analysis or theoretical modeling. The objective of this study is to quantify the morphometric dimension of the nasal airway of a New Zealand white rabbit and to relate the morphology and functions through analytical and computational methods. Images of high-resolution MRI scans of the rabbit were processed to measure the axial distribution of the cross-sectional areas, perimeter, and complexity level. The lateral recess, which has functions other than respiration or olfaction, was isolated from the nasal airway and its dimension was quantified separately. A low Reynolds number turbulence model was implemented to simulate the airflow, heat transfer, vapor transport, and wall shear stress. Results of this study provide detailed morphological information of the rabbit that can be used in the studies of olfaction, inhalation toxicology, drug delivery, and physiology-based pharmacokinetics modeling. For the first time, we reported a spiral nasal vestibule that splits into three paths leading to the dorsal meatus, maxilloturbinate, and ventral meatus, respectively. Both non-dimensional functional analysis and CFD simulations suggested that the airflow in the rabbit nose is laminar and the unsteady effect is only significantly during sniffing. Due to the large surface-to-volume ratio, the maxilloturbinate is highly effective in warming and moistening the inhaled air to body conditions. The unique anatomical structure and respiratory airflow pattern may have important implications for designing new odorant detectors or electronic noses. Anat Rec, 299:853-868, 2016. © 2016 Wiley Periodicals, Inc. PMID:27145450

  3. Extreme Air Pollution Conditions Adversely Affect Blood Pressure and Insulin Resistance: The Air Pollution and Cardiometabolic Disease Study.

    PubMed

    Brook, Robert D; Sun, Zhichao; Brook, Jeffrey R; Zhao, Xiaoyi; Ruan, Yanping; Yan, Jianhua; Mukherjee, Bhramar; Rao, Xiaoquan; Duan, Fengkui; Sun, Lixian; Liang, Ruijuan; Lian, Hui; Zhang, Shuyang; Fang, Quan; Gu, Dongfeng; Sun, Qinghua; Fan, Zhongjie; Rajagopalan, Sanjay

    2016-01-01

    Mounting evidence supports that fine particulate matter adversely affects cardiometabolic diseases particularly in susceptible individuals; however, health effects induced by the extreme concentrations within megacities in Asia are not well described. We enrolled 65 nonsmoking adults with metabolic syndrome and insulin resistance in the Beijing metropolitan area into a panel study of 4 repeated visits across 4 seasons since 2012. Daily ambient fine particulate matter and personal black carbon levels ranged from 9.0 to 552.5 µg/m(3) and 0.2 to 24.5 µg/m(3), respectively, with extreme levels observed during January 2013. Cumulative fine particulate matter exposure windows across the prior 1 to 7 days were significantly associated with systolic blood pressure elevations ranging from 2.0 (95% confidence interval, 0.3-3.7) to 2.7 (0.6-4.8) mm Hg per SD increase (67.2 µg/m(3)), whereas cumulative black carbon exposure during the previous 2 to 5 days were significantly associated with ranges in elevations in diastolic blood pressure from 1.3 (0.0-2.5) to 1.7 (0.3-3.2) mm Hg per SD increase (3.6 µg/m(3)). Both black carbon and fine particulate matter were significantly associated with worsening insulin resistance (0.18 [0.01-0.36] and 0.22 [0.04-0.39] unit increase per SD increase of personal-level black carbon and 0.18 [0.02-0.34] and 0.22 [0.08-0.36] unit increase per SD increase of ambient fine particulate matter on lag days 4 and 5). These results provide important global public health warnings that air pollution may pose a risk to cardiometabolic health even at the extremely high concentrations faced by billions of people in the developing world today. PMID:26573709

  4. Extreme Air Pollution Conditions Adversely Affect Blood Pressure and Insulin Resistance: The Air Pollution and Cardiometabolic Disease Study.

    PubMed

    Brook, Robert D; Sun, Zhichao; Brook, Jeffrey R; Zhao, Xiaoyi; Ruan, Yanping; Yan, Jianhua; Mukherjee, Bhramar; Rao, Xiaoquan; Duan, Fengkui; Sun, Lixian; Liang, Ruijuan; Lian, Hui; Zhang, Shuyang; Fang, Quan; Gu, Dongfeng; Sun, Qinghua; Fan, Zhongjie; Rajagopalan, Sanjay

    2016-01-01

    Mounting evidence supports that fine particulate matter adversely affects cardiometabolic diseases particularly in susceptible individuals; however, health effects induced by the extreme concentrations within megacities in Asia are not well described. We enrolled 65 nonsmoking adults with metabolic syndrome and insulin resistance in the Beijing metropolitan area into a panel study of 4 repeated visits across 4 seasons since 2012. Daily ambient fine particulate matter and personal black carbon levels ranged from 9.0 to 552.5 µg/m(3) and 0.2 to 24.5 µg/m(3), respectively, with extreme levels observed during January 2013. Cumulative fine particulate matter exposure windows across the prior 1 to 7 days were significantly associated with systolic blood pressure elevations ranging from 2.0 (95% confidence interval, 0.3-3.7) to 2.7 (0.6-4.8) mm Hg per SD increase (67.2 µg/m(3)), whereas cumulative black carbon exposure during the previous 2 to 5 days were significantly associated with ranges in elevations in diastolic blood pressure from 1.3 (0.0-2.5) to 1.7 (0.3-3.2) mm Hg per SD increase (3.6 µg/m(3)). Both black carbon and fine particulate matter were significantly associated with worsening insulin resistance (0.18 [0.01-0.36] and 0.22 [0.04-0.39] unit increase per SD increase of personal-level black carbon and 0.18 [0.02-0.34] and 0.22 [0.08-0.36] unit increase per SD increase of ambient fine particulate matter on lag days 4 and 5). These results provide important global public health warnings that air pollution may pose a risk to cardiometabolic health even at the extremely high concentrations faced by billions of people in the developing world today.

  5. Interaction between Chronic Obstructive Pulmonary Disease (COPD) and other important health conditions and measurable air pollution

    NASA Astrophysics Data System (ADS)

    Blagev, D. P.; Mendoza, D. L.; Rea, S.; Sorensen, J.

    2015-12-01

    Adverse health effects have been associated with urban pollutant exposure arising from close proximity to highly-emitting sources and atmospheric mixing. The relative air pollution exposure dose and time effects on various diseases remains unknown. This study compares the increased risk of health complications when patients are exposed to short term high-levels of air pollution vs. longer term exposure to lower levels of air pollution. We used the electronic medical record of an integrated hospital system based in Utah, Intermountain Healthcare, to identify a cohort of patients with Chronic Obstructive Pulmonary Disease (COPD) who were seen between 2009-2014. We determined patient demographics as well as comorbidity data and healthcare utilization. To determine the approximate air pollution dose and time exposure, we used the Hestia highly-resolved emissions inventory for Salt Lake County, Utah in conjunction with emissions based on the National Emissions Inventory (NEI). Hourly emissions of CO2 and criteria air pollutants were gridded at a 0.002o x 0.002o resolution for the study years. The resulting emissions were transported using the CALPUFF and AERMOD dispersion models to estimate air pollutant concentrations at an hourly 0.002o x 0.002oresolution. Additionally, pollutant concentrations were estimated at each patient's home and work address to estimate exposure. Multivariate analysis adjusting for patient demographics, comorbidities and severity of COPD was performed to determine association between air pollution exposure and the risk of hospitalization or emergency department (ED) visit for COPD exacerbation and an equivalency estimate for air pollution exposure was developed. We noted associations with air pollution levels for each pollutant and hospitalizations and ED visits for COPD and other patient comorbidities. We also present an equivalency estimate for dose of air pollution exposure and health outcomes. This analysis compares the increased risk of

  6. Evaluation of the magnitude and effects of bundle duct interaction in fuel assemblies at developmental plant conditions

    SciTech Connect

    Serell, D.C.; Kaplan, S.

    1980-09-01

    Purpose of this evaluation is to estimate the magnitude and effects of irradiation and creep induced fuel bundle deformations in the developmental plant. This report focuses on the trends of the results and the ability of present models to evaluate the assembly temperatures in the presence of bundle deformation. Although this analysis focuses on the developmental plant, the conclusions are applicable to LMFBR fuel assemblies in general if they have wire spacers.

  7. Plain-jet airblast atomization of alternative liquid petroleum fuels under high ambient air pressure conditions

    NASA Astrophysics Data System (ADS)

    Jasuja, A. K.

    1982-04-01

    The effects that air and fuel properties have upon the spray mean drop size characteristics of a plain-jet airblast atomizer of the type employed in the gas turbine engine are investigated. The tests used kerosene, gas oil and a high-viscosity blend of gas oil in residual fuel oil, and covered a wide range of ambient air pressures. Laser light-scattering technique was employed for drop size measurements. It is concluded that the atomizer's measured mean drop size characteristics are only slightly different from those of the pre-filming type, especially when operating on low-viscosity kerosene under higher ambient air pressure. The beneficial effect of increased levels of ambient air pressure on mean drop size is shown to be much reduced in the case of high-viscosity fuels, thus making the attainment of good atomization performance on such fuels difficult. An expression is derived for correlating the obtained mean drop size data.

  8. Atmospheric Thickness Variability During Air Mass Conditions and Winter Snow Events at Albany, NY: 2002-2012

    NASA Astrophysics Data System (ADS)

    Dubbs, A. M.; Swift, S.; Godek, M. L.

    2014-12-01

    A winter weather parameter that is underutilized in the prediction of Northeast snowfall events is critical thickness. Knowledge of atmospheric thickness values during snowfall can benefit the accuracy of winter forecasts, especially if thickness layer ranges at times without precipitation are known. This investigation aims to better understand atmospheric thickness variations in the 1000-500, 1000-700, and 1000-850 hPa layers at Albany, New York during snowfall with differing air mass conditions. Since snow can occur alongside a variety of air mass environments, distinctions in layer thickness between air mass types and critical levels will be examined. Pairing air mass information with an improved understanding of thicknesses may allow forecasters to determine normal snowfall conditions of the atmosphere and decipher when anomalous conditions are occurring alongside heavier snows. Daily geopotential height data are examined alongside Spatial Synoptic Classification weather types over the past decade. Air mass frequencies are computed and baseline thicknesses are established for non-snow days, days with snow and liquid precipitation, and days with only snowfall. Thicknesses are compared to those computed for seven air mass types and differences layers are examined for continuity. For the three air masses identified as prevalent during heavy snow, light-to-heavy and early-to-late season snowfall categories are established and thickness variations are evaluated against non-snow days for significant differences. Results indicate that the differences in layer thicknesses are comparable for all precipitation and non-snow days but around 40 geopotential meters less for pure-snow days. For air masses present during snow, layer thicknesses can vary by over 100 gpm with type. Isolating polar varieties, approximately 50 gpm thickness differences are found in pure-snow days. Comparable differences are detected between the moderate and polar types and the continuity between

  9. ASME N511-19XX, Standard for periodic in-service testing of nuclear air treatment, heating, ventilating and air conditioning systems

    SciTech Connect

    1997-08-01

    A draft version of the Standard is presented in this document. The Standard covers the requirements for periodic in-service testing of nuclear safety-related air treatment, heating, ventilating, and air conditioning systems in nuclear facilities. The Standard provides a basis for the development of test programs and does not include acceptance criteria, except in cases where the results of one test influence the performance of other tests. The Standard covers general inspection and test requirements, reference values, inspection and test requirements, generic tests, acceptance criteria, in-service test requirements, testing following an abnormal incident, corrective action requirements, and quality assurance. Mandatory appendices provide a visual inspection checklist and four test procedures. Non-mandatory appendices provide additional information and guidance on mounting frame pressure leak test procedure, corrective action, challenge gas substitute selection criteria, and test program development. 8 refs., 10 tabs.

  10. Study of Air Ingress Across the Duct During the Accident Conditions

    SciTech Connect

    Hassan, Yassin

    2013-05-06

    The goal of this project is to study the fundamental physical phenomena associated with air ingress in very high temperature reactors (VHTRs). Air ingress may occur due to a rupture of primary piping and a subsequent breach in the primary pressure boundary in helium-cooled and graphite-moderated VHTRs. Significant air ingress is a concern because it introduces potential to expose the fuel, graphite support rods, and core to a risk of severe graphite oxidation. Two of the most probable air ingress scenarios involve rupture of a control rod or fuel access standpipe, and rupture in the main coolant pipe on the lower part of the reactor pressure vessel. Therefore, establishing a fundamental understanding of air ingress phenomena is critical in order to rationally evaluate safety of existing VHTRs and develop new designs that minimize these risks. But despite this importance, progress toward development these predictive capabilities has been slowed by the complex nature of the underlying phenomena. The combination of inter-diffusion among multiple species, molecular diffusion, natural convection, and complex geometries, as well as the multiple chemical reactions involved, impose significant roadblocks to both modeling and experiment design. The project team will employ a coordinated experimental and computational effort that will help gain a deeper understanding of multiphased air ingress phenomena. This project will enhance advanced modeling and simulation methods, enabling calculation of nuclear power plant transients and accident scenarios with a high degree of confidence. The following are the project tasks: Perform particle image velocimetry measurement of multiphase air ingresses; and, Perform computational fluid dynamics analysis of air ingress phenomena.

  11. Exposure to negatively charged-particle dominant air-conditions on human lymphocytes in vitro activates immunological responses.

    PubMed

    Nishimura, Yasumitsu; Takahashi, Kazuaki; Mase, Akinori; Kotani, Muneo; Ami, Kazuhisa; Maeda, Megumi; Shirahama, Takashi; Lee, Suni; Matsuzaki, Hidenori; Kumagai-Takei, Naoko; Yoshitome, Kei; Otsuki, Takemi

    2015-12-01

    Indoor air-conditions may play an important role in human health. Investigation of house conditions that promote health revealed that negatively charged-particle dominant indoor air-conditions (NAC) induced immune stimulation. NAC was established using fine charcoal powder on walls and ceilings and utilizing forced negatively charged particles (approximate diameter: 20 nm) dominant in indoor air-conditions created by applying an electric voltage (72 V) between the backside of the walls and the ground. We reported previously that these conditions induced a slight and significant increase of interleukin-2 during 2.5 h stay, and an increase of natural killer (NK) cell cytotoxicity, when examining human subjects after a two-week night stay under these conditions. In the present study, we investigated whether exposure to NAC in vitro affects immune conditions. Although the concentrations of particles were different, an incubator for cell culture with NAC was set and cellular compositions and functions of various freshly isolated human lymphocytes derived from healthy donors were assayed in the NAC incubator and compared with those of cultures in a standard (STD) incubator. Results showed that NAC cultivation caused an increase of CD25 and PD-1 expressing cells in the CD4 positive fraction, enhancement of NK cell cytotoxicity, production of interferon-y (IFNγ), and slight enhancement of regulatory T cell function. In addition, the formula designated as the "immune-index" clearly differed between STD and NAC culture conditions. Thus, NAC conditions may promote human health through slight activation of the immune system against cancer cells and virus infection as shown by this in vitro study and our previously reported human studies.

  12. Impact of air pollution control measures and weather conditions on asthma during the 2008 Summer Olympic Games in Beijing.

    PubMed

    Li, Yi; Wang, Wen; Wang, Jizhi; Zhang, Xiaoling; Lin, Weili; Yang, Yuanqin

    2011-07-01

    The alternative transportation strategy implemented during the 2008 Summer Olympic Games in Beijing provided an opportunity to study the impact of the control measures and weather conditions on air quality and asthma morbidity. An ecological study compared the 41 days of the Olympic Games (8 August-17 September 2008) to a baseline period (1-30 June). Also, in order to emphasize the impact of weather conditions on air quality, a pollution linking meteorological index (Plam) was introduced to represent the air pollution meteorological condition. Our study showed that the average number of outpatient visits for asthma was 12.5 per day at baseline and 7.3 per day during the Olympics-a 41.6% overall decrease. Compared with the baseline, the Games were associated with a significant reduction in asthma visits (RR 0.58, 95%CI: 0.52-0.65). At 16.5 visits per day, asthma visits were also significantly higher, during the pre-Olympic period (RR 1.32, 95% CI: 1.15-1.52). The study also showed that the RR of asthma events on a given day, as well as the average daily peak ozone concentration during the preceding 48-72 h, increased at cumulative ozone concentrations of 70 to 100 ppb and 100 ppb or more compared with ozone concentrations of less than 70 ppb (P < 0.05). We concluded that along with "good" weather conditions, efforts to reduce traffic congestion in Beijing during the Olympic Games were associated with a prolonged reduction in air pollution and significantly lower rates of adult asthma events. These data provide support for efforts to reduce air pollution and improve health via reductions in motor vehicle traffic. PMID:21076997

  13. Impact of air pollution control measures and weather conditions on asthma during the 2008 Summer Olympic Games in Beijing.

    PubMed

    Li, Yi; Wang, Wen; Wang, Jizhi; Zhang, Xiaoling; Lin, Weili; Yang, Yuanqin

    2011-07-01

    The alternative transportation strategy implemented during the 2008 Summer Olympic Games in Beijing provided an opportunity to study the impact of the control measures and weather conditions on air quality and asthma morbidity. An ecological study compared the 41 days of the Olympic Games (8 August-17 September 2008) to a baseline period (1-30 June). Also, in order to emphasize the impact of weather conditions on air quality, a pollution linking meteorological index (Plam) was introduced to represent the air pollution meteorological condition. Our study showed that the average number of outpatient visits for asthma was 12.5 per day at baseline and 7.3 per day during the Olympics-a 41.6% overall decrease. Compared with the baseline, the Games were associated with a significant reduction in asthma visits (RR 0.58, 95%CI: 0.52-0.65). At 16.5 visits per day, asthma visits were also significantly higher, during the pre-Olympic period (RR 1.32, 95% CI: 1.15-1.52). The study also showed that the RR of asthma events on a given day, as well as the average daily peak ozone concentration during the preceding 48-72 h, increased at cumulative ozone concentrations of 70 to 100 ppb and 100 ppb or more compared with ozone concentrations of less than 70 ppb (P < 0.05). We concluded that along with "good" weather conditions, efforts to reduce traffic congestion in Beijing during the Olympic Games were associated with a prolonged reduction in air pollution and significantly lower rates of adult asthma events. These data provide support for efforts to reduce air pollution and improve health via reductions in motor vehicle traffic.

  14. Impact of air pollution control measures and weather conditions on asthma during the 2008 Summer Olympic Games in Beijing

    NASA Astrophysics Data System (ADS)

    Li, Yi; Wang, Wen; Wang, Jizhi; Zhang, Xiaoling; Lin, Weili; Yang, Yuanqin

    2011-07-01

    The alternative transportation strategy implemented during the 2008 Summer Olympic Games in Beijing provided an opportunity to study the impact of the control measures and weather conditions on air quality and asthma morbidity. An ecological study compared the 41 days of the Olympic Games (8 August-17 September 2008) to a baseline period (1-30 June). Also, in order to emphasize the impact of weather conditions on air quality, a pollution linking meteorological index (Plam) was introduced to represent the air pollution meteorological condition. Our study showed that the average number of outpatient visits for asthma was 12.5 per day at baseline and 7.3 per day during the Olympics—a 41.6% overall decrease. Compared with the baseline, the Games were associated with a significant reduction in asthma visits (RR 0.58, 95%CI: 0.52-0.65). At 16.5 visits per day, asthma visits were also significantly higher, during the pre-Olympic period (RR 1.32, 95% CI: 1.15-1.52). The study also showed that the RR of asthma events on a given day, as well as the average daily peak ozone concentration during the preceding 48-72 h, increased at cumulative ozone concentrations of 70 to 100 ppb and 100 ppb or more compared with ozone concentrations of less than 70 ppb ( P < 0.05). We concluded that along with "good" weather conditions, efforts to reduce traffic congestion in Beijing during the Olympic Games were associated with a prolonged reduction in air pollution and significantly lower rates of adult asthma events. These data provide support for efforts to reduce air pollution and improve health via reductions in motor vehicle traffic.

  15. Assessing the ability of mechanistic volatilization models to simulate soil surface conditions: a study with the Volt'Air model.

    PubMed

    Garcia, L; Bedos, C; Génermont, S; Braud, I; Cellier, P

    2011-09-01

    Ammonia and pesticide volatilization in the field is a surface phenomenon involving physical and chemical processes that depend on the soil surface temperature and water content. The water transfer, heat transfer and energy budget sub models of volatilization models are adapted from the most commonly accepted formalisms and parameterizations. They are less detailed than the dedicated models describing water and heat transfers and surface status. The aim of this work was to assess the ability of one of the available mechanistic volatilization models, Volt'Air, to accurately describe the pedo-climatic conditions of a soil surface at the required time and space resolution. The assessment involves: (i) a sensitivity analysis, (ii) an evaluation of Volt'Air outputs in the light of outputs from a reference Soil-Vegetation-Atmosphere Transfer model (SiSPAT) and three experimental datasets, and (iii) the study of three tests based on modifications of SiSPAT to establish the potential impact of the simplifying assumptions used in Volt'Air. The analysis confirmed that a 5 mm surface layer was well suited, and that Volt'Air surface temperature correlated well with the experimental measurements as well as with SiSPAT outputs. In terms of liquid water transfers, Volt'Air was overall consistent with SiSPAT, with discrepancies only during major rainfall events and dry weather conditions. The tests enabled us to identify the main source of the discrepancies between Volt'Air and SiSPAT: the lack of gaseous water transfer description in Volt'Air. They also helped to explain why neither Volt'Air nor SiSPAT was able to represent lower values of surface water content: current classical water retention and hydraulic conductivity models are not yet adapted to cases of very dry conditions. Given the outcomes of this study, we discuss to what extent the volatilization models can be improved and the questions they pose for current research in water transfer modeling and parameterization

  16. Heat waves observed in 2007 in Athens, Greece: synoptic conditions, bioclimatological assessment, air quality levels and health effects.

    PubMed

    Theoharatos, George; Pantavou, Katerina; Mavrakis, Anastasios; Spanou, Anastasia; Katavoutas, George; Efstathiou, Panos; Mpekas, Periklis; Asimakopoulos, Dimosthenis

    2010-02-01

    Heat waves are considered to be increasing in frequency and intensity whereas they comprise a significant weather-related cause of deaths in several countries. Two heat waves occurred in Greece in summer 2007. These severe heat waves are assessed by analyzing the prevailing synoptic conditions, evaluating human thermal discomfort, through the Heat Load Index (HL), as well as investigating its interrelation of air pollutant concentrations, and the daily air quality stress index (AQSI), in the greater region of Athens (Attica), Greece. Furthermore, the relation of HL values and the number of heatstroke and heat exhaustion events recorded in public hospitals operating within the Greek National Health System is examined. Data included radiosonde measurements from the Athens airport station (LGAT), NCEP/NCAR reanalysis data in order to obtain the position of the Subtropical Jet Stream (STJ), GDAS meteorological data for back-trajectory calculation, 10-min meteorological data from 10 Hydro-Meteorological stations and mean hourly values of nitric dioxide (NO(2)), sulphur dioxide (SO(2)) and ozone (O(3)) concentrations, measured at 7 different sites, for the last 10-day period of June and July 2007. Spearman's rank correlation test was used to observe any possible correlation between HL values and air pollutant concentrations, and AQSI values. The results demonstrated different synoptic characteristics for the heat waves of June and July. In the heat wave of June, higher ambient temperatures were recorded and greater HL values were calculated. Extreme discomfort conditions were identified in both heat waves during both day-time and night-time hours. The air pollution analysis showed poor air quality conditions for the heat wave of July, while a significant correlation was found between HL values and average hourly concentrations of O(3), NO(2) and SO(2). The number of heat-affected patients reported during the June heat wave was larger. PMID:20060520

  17. Heat waves observed in 2007 in Athens, Greece: synoptic conditions, bioclimatological assessment, air quality levels and health effects.

    PubMed

    Theoharatos, George; Pantavou, Katerina; Mavrakis, Anastasios; Spanou, Anastasia; Katavoutas, George; Efstathiou, Panos; Mpekas, Periklis; Asimakopoulos, Dimosthenis

    2010-02-01

    Heat waves are considered to be increasing in frequency and intensity whereas they comprise a significant weather-related cause of deaths in several countries. Two heat waves occurred in Greece in summer 2007. These severe heat waves are assessed by analyzing the prevailing synoptic conditions, evaluating human thermal discomfort, through the Heat Load Index (HL), as well as investigating its interrelation of air pollutant concentrations, and the daily air quality stress index (AQSI), in the greater region of Athens (Attica), Greece. Furthermore, the relation of HL values and the number of heatstroke and heat exhaustion events recorded in public hospitals operating within the Greek National Health System is examined. Data included radiosonde measurements from the Athens airport station (LGAT), NCEP/NCAR reanalysis data in order to obtain the position of the Subtropical Jet Stream (STJ), GDAS meteorological data for back-trajectory calculation, 10-min meteorological data from 10 Hydro-Meteorological stations and mean hourly values of nitric dioxide (NO(2)), sulphur dioxide (SO(2)) and ozone (O(3)) concentrations, measured at 7 different sites, for the last 10-day period of June and July 2007. Spearman's rank correlation test was used to observe any possible correlation between HL values and air pollutant concentrations, and AQSI values. The results demonstrated different synoptic characteristics for the heat waves of June and July. In the heat wave of June, higher ambient temperatures were recorded and greater HL values were calculated. Extreme discomfort conditions were identified in both heat waves during both day-time and night-time hours. The air pollution analysis showed poor air quality conditions for the heat wave of July, while a significant correlation was found between HL values and average hourly concentrations of O(3), NO(2) and SO(2). The number of heat-affected patients reported during the June heat wave was larger.

  18. Multiple H-bonds directed self-assembly of an amphiphilic and plate-like codendrimer with janus faces at water-air interface.

    PubMed

    Yang, Miao; Wang, Wei; Lieberwirth, Ingo; Wegner, Gerhard

    2009-05-01

    An amphiphilic diblock codendrimer composed of a third generation poly(methallyl dichloride) end-capped by eight hydroxyl groups (PMDC(OH)(8)) and a second generation poly(urethane amide) end-capped by four alkyl groups (PUA(C16)(4)) were found to self-assemble into highly oriented ribbons at the water-air interface. Further investigation on the ribbon formation shows that the ribbons are hierarchically self-organized by the janus and plate-like shape of g3-PMDC(OH)(8)-b-g2-PUA(C16)(4). Sextuple H-bonds existing at different positions of the molecular plate are the main driving force for the one-dimensional growth of the ribbon. The recognition of these H-bonds leads to a highly ordered stacking of the codendrimers, and the crystallization of the alkyl chains results in a primary ribbon with a ca. 7.6 +/- 0.5 nm width. The primary ribbons prefer to organize into secondary ribbons with an average width of 53 +/- 6.0 nm. The manner of recognition and assembly is similar to the organization of a kind of toy building block with janus faces, which provides a new strategy to the design of well-defined nanomaterials. PMID:19361164

  19. Evaluation of rotor-bearing system dynamic response to unbalance. [air conditioning equipment

    NASA Technical Reports Server (NTRS)

    Thaller, R. E.; Ozimek, D. W.

    1979-01-01

    The vibration environment within air conditioner rotating machinery referred to as an air cycle machine (ACM) was investigated to effectively increase ACM reliability. To assist in the selection of design changes which would result in improved ACM performance, various design modifications were incorporated into a baseline ACM configuration. For each design change, testing was conducted with the best balance achieveable (baseline) and with various degrees of unbalance. Relationships between unbalance (within the context of design changes) and the parameters associated with design goals were established. The results of rotor dynamics tests used to establish these relationships are presented.

  20. Shelf life of air and modified atmosphere-packaged fresh tilapia (Oreochromis niloticus) fillets stored under chilled and superchilled conditions.

    PubMed

    Cyprian, Odoli; Lauzon, Hélène L; Jóhannsson, Ragnar; Sveinsdóttir, Kolbrún; Arason, Sigurjón; Martinsdóttir, Emilía

    2013-03-01

    Optimal packaging and storage conditions for fresh tilapia fillets were established by evaluating sensory and microbiological changes, as well as monitoring physicochemical properties. Nile tilapia (Oreochromis niloticus) farmed in recirculation aquaculture system was filleted, deskinned, and packaged in air and 50% CO2/50% N2 prior to chilling and superchilling storage at 1°C and -1°C. Sensory analysis of cooked samples revealed a shelf life of 13-15 days for air-packaged fillets during storage at 1°C and 20 days at -1°C. At the end of shelf life in air-packaged fillets, total viable counts (TVC) and pseudomonads counts reached log 8 colony-forming units (CFU) g(-1). In 50% CO2/50% N2-packaged fillets, the lag phase and generation time of bacteria were extended and recorded counts were below the limit for consumption (air packaged at -1°C storage temperature was the optimal condition for fresh tilapia fillets. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) were not good indicators of spoilage of tilapia fillets in this study. PMID:24804022