Science.gov

Sample records for air ventilation system

  1. Heating, Ventilating, Air Conditioning and Dehumidifying Systems.

    DTIC Science & Technology

    1980-08-01

    not be connected to other ventilating systems. Duct runs shall be as short as possible to avoid leakage of moisture. I b. Special Considerations. (1...For rectangular duct design, see the SMACNA -Low Pressure Duct Construction Standards. Under jnormal applications, a minimum duct size of 6 by 6 inches...prevent leakage of the moisture-laden discharge air into the intake duct , and the intake and discharge outlets shall be located to prevent any

  2. [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.

  3. Position paper -- Tank ventilation system design air flow rates

    SciTech Connect

    Goolsby, G.K.

    1995-01-04

    The purpose of this paper is to document a project position on required ventilation system design air flow rates for the waste storage tanks currently being designed by project W-236A, the Multi-Function Waste Tank Facility (MWTF). The Title 1 design primary tank heat removal system consists of two systems: a primary tank vapor space ventilation system; and an annulus ventilation system. At the conclusion of Title 1 design, air flow rates for the primary and annulus ventilation systems were 960 scfm and 4,400 scfm, respectively, per tank. These design flow rates were capable of removing 1,250,000 Btu/hr from each tank. However, recently completed and ongoing studies have resulted in a design change to reduce the extreme case heat load to 700,000 Btu/hr. This revision of the extreme case heat load, coupled with results of scale model evaporative testing performed by WHC Thermal Hydraulics, allow for a reduction of the design air flow rates for both primary and annulus ventilation systems. Based on the preceding discussion, ICF Kaiser Hanford Co. concludes that the design should incorporate the following design air flow rates: Primary ventilation system--500 scfm maximum and Annulus ventilation system--1,100 scfm maximum. In addition, the minimum air flow rates in the primary and annulus ventilation systems will be investigated during Title 2 design. The results of the Title 2 investigation will determine the range of available temperature control using variable air flows to both ventilation systems.

  4. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    Rudd, A.; Bergey, D.

    2014-02-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. It was inferior because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  5. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    Rudd, Armin; Bergey, Daniel

    2014-02-01

    In this project, Building America research team Building Science Corporation tested the effectiveness of ventilation systems at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. This was because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four system factor categories: balance, distribution, outside air source, and recirculation filtration. Recommended system factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  6. Heating, Ventilation and Air-Conditioning Systems, Part of Indoor Air Quality Design Tools for Schools

    EPA Pesticide Factsheets

    The main purposes of a Heating, Ventilation, and Air-Conditioning system are to help maintain good indoor air quality through adequate ventilation with filtration and provide thermal comfort. HVAC systems are among the largest energy consumers in schools.

  7. Measured Air Distribution Effectiveness for Residential Mechanical Ventilation Systems

    SciTech Connect

    Sherman, Max; Sherman, Max H.; Walker, Iain S.

    2008-05-01

    The purpose of ventilation is dilute or remove indoor contaminants that an occupant is exposed to. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. Most US homes have central HVAC systems, which tend to mix the air thus the indoor conditions between zones. Different types of ventilation systems will provide different amounts of exposure depending on the effectiveness of their air distribution systems and the location of sources and occupants. This paper will report on field measurements using a unique multi-tracer measurement system that has the capacity to measure not only the flow of outdoor air to each zone, but zone-to-zone transport. The paper will derive seven different metrics for the evaluation of air distribution. Measured data from two homes with different levels of natural infiltration will be used to evaluate these metrics for three different ASHRAE Standard 62.2 compliant ventilation systems. Such information can be used to determine the effectiveness of different systems so that appropriate adjustments can be made in residential ventilation standards such as ASHRAE Standard 62.2.

  8. Ventilating Air-Conditioner

    NASA Technical Reports Server (NTRS)

    Dinh, Khanh

    1994-01-01

    Air-conditioner provides ventilation designed to be used alone or incorporated into cooling or heating system operates efficiently only by recirculating stale air within building. Energy needed to operate overall ventilating cooling or heating system slightly greater than operating nonventilating cooling or heating system. Helps to preserve energy efficiency while satisfying need for increased forced ventilation to prevent accumulation of undesired gases like radon and formaldehyde. Provides fresh treated air to variety of confined spaces: hospital surgeries, laboratories, clean rooms, and printing shops and other places where solvents used. In mobile homes and portable classrooms, eliminates irritant chemicals exuded by carpets, panels, and other materials, ensuring healthy indoor environment for occupants.

  9. Technology Solutions Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    A. Rudd and D. Bergey

    2015-08-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs.

  10. [Sanitary and epidemiological evaluation of the ventilation and air-conditioning systems of public buildings].

    PubMed

    Dvorianov, V V

    2012-01-01

    The microbial contamination of ventilation and air conditioning systems was examined in the administrative buildings. The author proposes a set of indicators, methods for determining the scope of investigations, as well as sampling tactics and criteria for evaluating the microbial contamination of the ventilation and air-conditioning systems. The content of yeasts and molds in the delivered air has been found to be of importance for evaluating the sanitary-and epidemiological state of ventilation systems.

  11. Building America Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts, Tyler, Texas

    SciTech Connect

    2015-08-01

    ?Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy.

  12. 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.

  13. VENTILATION TECHNOLOGY SYSTEMS ANALYSIS

    EPA Science Inventory

    The report gives results of a project to develop a systems analysis of ventilation technology and provide a state-of-the-art assessment of ventilation and indoor air quality (IAQ) research needs. (NOTE: Ventilation technology is defined as the hardware necessary to bring outdoor ...

  14. [Invention of an air forced ventilated micro-isolation cage and rack system--environment within the cages: ventilation, air flow].

    PubMed

    Kurosawa, T; Yoshida, K; Okamoto, M; Tajima, M

    1993-10-01

    A forced air ventilation system for small laboratory animals was developed. The system consists of an air handling unit with air supply and exhaust fans, a rack, hard cage covers with a large diameter air inlet and an outlet, and shoe box cages. Air flow from the supply duct, to the exhaust duct and within the cage were observed. Variations in air flow among cages was minimal. The optimal air exchange rate of the cages in this system was determined to be 60 times per hour based on the results obtained in the present study. At this air exchange rate, air flow at the base of the cages had a velocity of less than 0.09m/sec, which was within the range of recommended values for humans. The observed results show that the system developed is capable of sustaining a laboratory animal microenvironment well in terms of air flow, without too much energy cost.

  15. Test Protocol for Room-to-Room Distribution of Outside Air by Residential Ventilation Systems

    SciTech Connect

    Barley, C. D.; Anderson, R.; Hendron, B.; Hancock, E.

    2007-12-01

    This test and analysis protocol has been developed as a practical approach for measuring outside air distribution in homes. It has been used successfully in field tests and has led to significant insights on ventilation design issues. Performance advantages of more sophisticated ventilation systems over simpler, less-costly designs have been verified, and specific problems, such as airflow short-circuiting, have been identified.

  16. Central Fan Integrated Ventilation Systems

    SciTech Connect

    2009-05-12

    This information sheet describes one example of a ventilation system design, a central fan integrated supply (CFIS) system, a mechanical ventilation and pollutant source control to ensure that there is reasonable indoor air quality inside the house.

  17. Experimental Evaluation of a Downsized Residential Air Distribution System: Comfort and Ventilation Effectiveness

    SciTech Connect

    Jalalzadeh-Azar, A. A.

    2007-01-01

    Good air mixing not only improves thermal comfort Human thermal comfort is the state of mind that expresses satisfaction with the surrounding environment, according to ASHRAE Standard 55. Achieving thermal comfort for most occupants of buildings or other enclosures is a goal of HVAC design engineers. but also enhances ventilation effectiveness by inducing uniform supply-air diffusion. In general, the performance of an air distribution system in terms of comfort and ventilation effectiveness is influenced by the supply air temperature, velocity, and flow rate, all of which are in part dictated by the HVAC (Heating Ventilation Air Conditioning) In the home or small office with a handful of computers, HVAC is more for human comfort than the machines. In large datacenters, a humidity-free room with a steady, cool temperature is essential for the trouble-free system as well as the thermal load attributes. Any potential deficiencies associated with these design variables can be further exacerbated by an improper proximity of the supply and return outlets with respect to the thermal and geometrical characteristics of the indoor space. For high-performance houses, the factors influencing air distribution performance take on an even greater significance because of a reduced supply-air design flow rate resulting from downsized HVAC systems.

  18. A comparison of air leakage prediction techniques for auxiliary ventilation ducting systems

    SciTech Connect

    Gillies, A.D.S.; Wu, H.W.

    1999-07-01

    This paper briefly reviews prediction techniques for determination of leakage and friction along auxiliary ventilation ducting systems. In order to compare various prediction techniques that have been developed over the past, a macroscopic investigation of air leakage and friction resistance of auxiliary ventilation ducting systems has been undertaken. Measurements were conducted on 450 and 915 mm diameter fabric ducting over 100 m duct length to determine frictional resistances and the extent of leakage. Due to the high degree of accuracy required and the large volume of data that needed to be collected, electronic auxiliary ventilation ducting systems were developed based on this information. It was found that these models provided good correlation with most the existing prediction techniques. The experimental methodology relying on computer data acquisition has allowed the accuracy of measured values to be treated with a high degree of confidence. The reliability of the developed models allows prediction of leakage, frictional impedance and airflow with enhanced confidence.

  19. Transpired Air Collectors - Ventilation Preheating

    SciTech Connect

    Christensen, C.

    2006-06-22

    Many commercial and industrial buildings have high ventilation rates. Although all that fresh air is great for indoor air quality, heating it can be very expensive. This short (2-page) fact sheet describes a technology available to use solar energy to preheat ventilation air and dramatically reduce utility bills.

  20. 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.

  1. Acoustical prediction methods for heating, ventilating, and air-conditioning (HVAC) systems

    NASA Astrophysics Data System (ADS)

    Ryherd, S. R.; Wang, L. M.

    2005-09-01

    The goal of this project is to compare and contrast various aspects of acoustical prediction methods for heating, ventilating, and air-conditioning (HVAC) systems. The three methods include two commonly used software programs and a custom spread sheet developed by the authors based on the American's Society of Heating, Refrigeration, and Air-conditioning Engineers (ASHRAE) Applications Handbook. Preliminary results indicate relatively good agreement between the three methods analyzed. The degree of disparity is predominately effected by the assumptions required by the end user. Research methods and results will be presented. This project provides a greater understanding of these acoustical prediction methods and their limitations.

  2. Centrifugal Blower for Personal Air Ventilation System (PAVS) - Phase 1

    DTIC Science & Technology

    2015-02-01

    axial blower design was chosen to achieve the highest possible efficiency within the size constraints of the system. The blower is able to deliver 10...of the blower were used to minimize losses and increase efficiency through adjustments of the specific blower geometry. CFD outputs included the...functionality. 15. SUBJECT TERMS COOLING SBIR REPORTS AXIAL FLOW FANS OFF THE SHELF EQUIPMENT BLOWERS LIGHTWEIGHT CENTRIFUGAL FORCE

  3. Heating, Ventilating, and Air-Conditioning: Recent Advances in Diagnostics and Controls to Improve Air-Handling System Performance

    SciTech Connect

    Wray, Craig; Wray, Craig P.; Sherman, Max H.; Walker, I.S.; Dickerhoff, D.J.; Federspiel, C.C.

    2008-02-01

    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.

  4. 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.

  5. 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.

  6. Preoperational test report, vent building ventilation system

    SciTech Connect

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Vent Building Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides Heating, Ventilation, and Air Conditioning (HVAC) for the W-030 Ventilation Building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  7. Safety demonstration tests of hypothetical explosive burning in the cell and air ventilation system in a nuclear fuel reprocessing plant

    SciTech Connect

    Nisio, G.; Suzuki, M.; Mukaide, S. )

    1991-09-01

    This paper reports on a nuclear fuel reprocessing plant equipped with an air ventilation system consisting of cells, ducts, dampers, high-efficiency particulate air filters, and blowers. This ventilation system is required to have multiple safeguards in order to confine airborne radioactive materials within the plant in the event of fire, explosion, and criticality. To evaluate these safeguards, three kinds of explosive burning tests are performed using a large-scale facility simulating the ventilation system of a reprocessing plant. In the boilover test, an organic solvent is burned on a layer of water in a burning pan to determine the magnitude of the burning caused by the sudden boiling of the water under the solvent. The optimum conditions for boilover burning are determined by the relationship between the pan size and the ventilation rate.

  8. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    SciTech Connect

    Sherman, Max H.; Walker, Iain S.

    2011-04-01

    Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outdoor pollutant levels are high, the importance of minimizing energy use particularly during times of peak electricity demand, and how the energy used to condition air as part of ventilation system operation changes with outdoor conditions. Dynamic control of ventilation systems can provide ventilation equivalent to or better than what is required by standards while minimizing energy costs and can also add value by shifting load during peak times and reducing intake of outdoor air contaminants. This article describes the logic that enables dynamic control of whole-house ventilation systems to meet the intent of ventilation standards and demonstrates the dynamic ventilation system control concept through simulations and field tests of the Residential Integrated Ventilation-Energy Controller (RIVEC).

  9. 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

  10. Effect of heating-ventilation-air conditioning system sanitation on airborne fungal populations in residential environments.

    PubMed

    Garrison, R A; Robertson, L D; Koehn, R D; Wynn, S R

    1993-12-01

    Commercial air duct sanitation services are advertised to the public as being effective in reducing indoor aeroallergen levels despite the absence of published supporting data. Eight residential heat-ventilation-air conditioning (HVAC) systems in six homes and seven HVAC systems in five homes in winter and summer, respectively, were sampled to determine fungal colony forming units (CFUs) prior to and after an HVAC sanitation procedure was performed by a local company. Two houses in which no sanitation procedure was performed served as controls in each study phase. Two sample sets were obtained at each HVAC system prior to cleaning in order to determine baseline CFU levels. The test HVAC systems were then cleaned, and the HVAC systems allowed to operate as desired by the residents. Posttreatment sampling was performed 48 hours and then weekly after cleaning for 8 weeks. The HVAC systems were analyzed by exposing sterile 2% malt extract media plates at a 90-degree angle to the air flow at the air supply and air return vents. The baseline CFUs were similar in the control and study houses. Eight weeks after sanitation, the study houses demonstrated an overall CFU reduction of 92% during winter and 84% during summer. No reduction in CFU values was observed over the 8-week study period for the houses selected as controls. Further, HVAC sanitation appeared to reduce the number of fungal colonies entering and leaving the HVAC system, suggesting that the HVAC contained a significant percentage of the total fungal load in these homes. These data suggest that HVAC sanitation may be an effective tool in reducing airborne fungal populations in residential environments.

  11. 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…

  12. 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.

  13. Ontology for Life-Cycle Modeling of Heating, Ventilating, and Air Conditioning (HVAC) Systems: Experimental Applications Using Revit

    DTIC Science & Technology

    2012-03-01

    Center, Construction Engineering Research Laboratory (ERDC-CERL) has developed a core life- cycle building information model ( BIM ) based on three...was to promote consistency and quality of content created for Building Information Models ( BIMs ) across various disciplines. The HVAC MVD was...MVD. 15. SUBJECT TERMS building information modeling ( BIM ), ontology, Army facilities, heating, ventilating, and air-conditioning (HVAC) systems

  14. Ventilation air, the economy cycle, and VAV

    SciTech Connect

    Haines, R.W.

    1994-10-01

    This article describes a simple yet effective method of providing both minimum and economy cycle control of outside air with a VAV system. Like most of the people in the HVAC industry, the author has been aware that there are problems with ventilation air and economy cycle outside air control when variable air volume (VAV) systems are used. It seemed obvious that the simple solution was to use an injection fan in the outside air intake to provide the minimum ventilation requirement under any operating condition of the VAV system and--presto--the problem would be solved. Recently the author was asked to prepare a seminar on HVAC controls for one of the ASHRAE chapters, with special emphasis on VAV systems. This forced him to take a careful look at the situation, and in the ensuing analysis, it became apparent that the previous look at the problem had not discovered the simplest and perhaps best solution.

  15. 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.

  16. Equivalence in Ventilation and Indoor Air Quality

    SciTech Connect

    Sherman, Max; Walker, Iain; Logue, Jennifer

    2011-08-01

    We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

  17. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... ventilation shall be installed within a horizontal distance of not more than ten feet from the vertical...

  18. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... ventilation shall be installed within a horizontal distance of not more than ten feet from the vertical...

  19. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... as to provide the level and quality of ventilation specified and designed by the manufacturer for the... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  20. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... as to provide the level and quality of ventilation specified and designed by the manufacturer for the... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  1. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... as to provide the level and quality of ventilation specified and designed by the manufacturer for the... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  2. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... as to provide the level and quality of ventilation specified and designed by the manufacturer for the... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  3. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... as to provide the level and quality of ventilation specified and designed by the manufacturer for the... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  4. Protective garment ventilation system

    NASA Technical Reports Server (NTRS)

    Lang, R. (Inventor)

    1970-01-01

    A method and apparatus for ventilating a protective garment, space suit system, and/or pressure suits to maintain a comfortable and nontoxic atmosphere within is described. The direction of flow of a ventilating and purging gas in portions of the garment may be reversed in order to compensate for changes in environment and activity of the wearer. The entire flow of the ventilating gas can also be directed first to the helmet associated with the garment.

  5. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... appliance listing and the appliance manufacturer's instructions. (b) Venting and combustion air...

  6. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... appliance listing and the appliance manufacturer's instructions. (b) Venting and combustion air...

  7. Whole house particle removal and clean air delivery rates for in-duct and portable ventilation systems.

    PubMed

    Macintosh, David L; Myatt, Theodore A; Ludwig, Jerry F; Baker, Brian J; Suh, Helen H; Spengler, John D

    2008-11-01

    A novel method for determining whole house particle removal and clean air delivery rates attributable to central and portable ventilation/air cleaning systems is described. The method is used to characterize total and air-cleaner-specific particle removal rates during operation of four in-duct air cleaners and two portable air-cleaning devices in a fully instrumented test home. Operation of in-duct and portable air cleaners typically increased particle removal rates over the baseline rates determined in the absence of operating a central fan or an indoor air cleaner. Removal rates of 0.3- to 0.5-microm particles ranged from 1.5 hr(-1) during operation of an in-duct, 5-in. pleated media filter to 7.2 hr(-1) for an in-duct electrostatic air cleaner in comparison to a baseline rate of 0 hr(-1) when the air handler was operating without a filter. Removal rates for total particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5) mass concentrations were 0.5 hr(-1) under baseline conditions, 0.5 hr(-1) during operation of three portable ionic air cleaners, 1 hr(-1) for an in-duct 1-in. media filter, 2.4 hr(-1) for a single high-efficiency particle arrestance (HEPA) portable air cleaner, 4.6 hr(-1) for an in-duct 5-in. media filter, 4.7 hr(-1) during operation of five portable HEPA filters, 6.1 hr(-1) for a conventional in-duct electronic air cleaner, and 7.5 hr(-1) for a high efficiency in-duct electrostatic air cleaner. Corresponding whole house clean air delivery rates for PM2.5 attributable to the air cleaner independent of losses within the central ventilation system ranged from 2 m3/min for the conventional media filter to 32 m3/min for the high efficiency in-duct electrostatic device. Except for the portable ionic air cleaner, the devices considered here increased particle removal indoors over baseline deposition rates.

  8. 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.

  9. 4. VENTILATION FAN SHOWING RELATIVE POSITION IN THE AIR TUNNEL. ...

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

    4. VENTILATION FAN SHOWING RELATIVE POSITION IN THE AIR TUNNEL. - Hot Springs National Park, Bathhouse Row, Ozark Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  10. Development and Design of a User Interface for a Computer Automated Heating, Ventilation, and Air Conditioning System

    SciTech Connect

    Anderson, B.; /Fermilab

    1999-10-08

    A user interface is created to monitor and operate the heating, ventilation, and air conditioning system. The interface is networked to the system's programmable logic controller. The controller maintains automated control of the system. The user through the interface is able to see the status of the system and override or adjust the automatic control features. The interface is programmed to show digital readouts of system equipment as well as visual queues of system operational statuses. It also provides information for system design and component interaction. The interface is made easier to read by simple designs, color coordination, and graphics. Fermi National Accelerator Laboratory (Fermi lab) conducts high energy particle physics research. Part of this research involves collision experiments with protons, and anti-protons. These interactions are contained within one of two massive detectors along Fermilab's largest particle accelerator the Tevatron. The D-Zero Assembly Building houses one of these detectors. At this time detector systems are being upgraded for a second experiment run, titled Run II. Unlike the previous run, systems at D-Zero must be computer automated so operators do not have to continually monitor and adjust these systems during the run. Human intervention should only be necessary for system start up and shut down, and equipment failure. Part of this upgrade includes the heating, ventilation, and air conditioning system (HVAC system). The HVAC system is responsible for controlling two subsystems, the air temperatures of the D-Zero Assembly Building and associated collision hall, as well as six separate water systems used in the heating and cooling of the air and detector components. The BYAC system is automated by a programmable logic controller. In order to provide system monitoring and operator control a user interface is required. This paper will address methods and strategies used to design and implement an effective user interface

  11. Characteristics of coal mine ventilation air flows.

    PubMed

    Su, Shi; Chen, Hongwei; Teakle, Philip; Xue, Sheng

    2008-01-01

    Coal mine methane (CMM) is not only a greenhouse gas but also a wasted energy resource if not utilised. Underground coal mining is by far the most important source of fugitive methane emissions, and approximately 70% of all coal mining related methane is emitted to the atmosphere through mine ventilation air. Therefore, research and development on mine methane mitigation and utilisation now focuses on methane emitted from underground coal mines, in particular ventilation air methane (VAM) capture and utilisation. To date, most work has focused on the oxidation of very low concentration methane. These processes may be classified based on their combustion kinetic mechanisms into thermal oxidation and catalytic oxidation. VAM mitigation/utilisation technologies are generally divided into two basic categories: ancillary uses and principal uses. However, it is possible that the characteristics of ventilation air flows, for example the variations in methane concentration and the presence of certain compounds, which have not been reported so far, could make some potential VAM mitigation and utilisation technologies unfeasible if they cannot cope with the characteristics of mine site ventilation air flows. Therefore, it is important to understand the characteristics of mine ventilation air flows. Moreover, dust, hydrogen sulphide, sulphur dioxide, and other possible compounds emitted through mine ventilation air into the atmosphere are also pollutants. Therefore, this paper presents mine-site experimental results on the characteristics of mine ventilation air flows, including methane concentration and its variations, dust loadings, particle size, mineral matter of the dust, and other compounds in the ventilation air flows. The paper also discusses possible correlations between ventilation air characteristics and underground mining activities.

  12. New Air Cleaning Strategies for Reduced Commercial Building Ventilation Energy

    SciTech Connect

    Sidheswaran, Meera; Destaillats, Hugo; Sullivan, Douglas P.; Fisk, William J.

    2010-10-27

    Approximately ten percent of the energy consumed in U.S. commercial buildings is used by HVAC systems to condition outdoor ventilation air. Reducing ventilation rates would be a simple and broadly-applicable energy retrofit option, if practical counter measures were available that maintained acceptable concentrations of indoor-generated air pollutants. The two general categories of countermeasures are: 1) indoor pollutant source control, and 2) air cleaning. Although pollutant source control should be used to the degree possible, source control is complicated by the large number and changing nature of indoor pollutant sources. Particle air cleaning is already routinely applied in commercial buildings. Previous calculations indicate that particle filtration consumes only 10percent to 25percent of the energy that would otherwise be required to achieve an equivalent amount of particle removal with ventilation. If cost-effective air cleaning technologies for volatile organic compounds (VOCs) were also available, outdoor air ventilation rates could be reduced substantially and broadly in the commercial building stock to save energy. The research carried out in this project focuses on developing novel VOC air cleaning technologies needed to enable energy-saving reductions in ventilation rates. The minimum required VOC removal efficiency to counteract a 50percent reduction in ventilation rate for air cleaning systems installed in the HVAC supply airstream is modest (generally 20percent or less).

  13. Innovative ventilation system for animal anatomy laboratory

    SciTech Connect

    Lacey, D.R.; Smith, D.C.

    1997-04-01

    A unique ventilation system was designed and built to reduce formaldehyde fumes in the large animal anatomy lab at the Vet Medical Center at Cornell University. The laboratory includes four rooms totaling 5,500 ft{sup 2}. The main room has 2,300 ft{sup 2} and houses the laboratory where up to 60 students dissect as many as 12 horses at a time. Other rooms are a cold storage locker, an animal preparation room and a smaller lab for specialized instruction. The large animal anatomy laboratory has a history of air quality complaints despite a fairly high ventilation rate of over 10 air changes/hour. The horses are embalmed, creating a voluminous source of formaldehyde and phenol vapors. Budget constraints and increasingly stringent exposure limits for formaldehyde presented a great challenge to design a ventilation system that yields acceptable air quality. The design solution included two innovative elements: air-to-air heat recovery, and focused ventilation.

  14. Transmission of Mycobacterium chimaera from Heater–Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System

    PubMed Central

    Sommerstein, Rami; Rüegg, Christian; Kohler, Philipp; Bloemberg, Guido; Kuster, Stefan P.

    2016-01-01

    Heater–cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices. PMID:27070958

  15. Transmission of Mycobacterium chimaera from Heater-Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System.

    PubMed

    Sommerstein, Rami; Rüegg, Christian; Kohler, Philipp; Bloemberg, Guido; Kuster, Stefan P; Sax, Hugo

    2016-06-01

    Heater-cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices.

  16. Heat Recovery Ventilation for Housing: Air-to-Air Heat Exchangers.

    ERIC Educational Resources Information Center

    Corbett, Robert J.; Miller, Barbara

    The air-to-air heat exchanger (a fan powered ventilation device that recovers heat from stale outgoing air) is explained in this six-part publication. Topic areas addressed are: (1) the nature of air-to-air heat exchangers and how they work; (2) choosing and sizing the system; (3) installation, control, and maintenance of the system; (4) heat…

  17. Using a Ventilation Controller to Optimize Residential Passive Ventilation For Energy and Indoor Air Quality

    SciTech Connect

    Turner, William; Walker, Iain

    2014-08-01

    One way to reduce the energy impact of providing residential ventilation is to use passive and hybrid systems. However, these passive and hybrid (sometimes called mixed-mode) systems must still meet chronic and acute health standards for ventilation. This study uses a computer simulation approach to examine the energy and indoor air quality (IAQ) implications of passive and hybrid ventilation systems, in 16 California climate zones. Both uncontrolled and flow controlled passive stacks are assessed. A new hybrid ventilation system is outlined that uses an intelligent ventilation controller to minimise energy use, while ensuring chronic and acute IAQ standards are met. ASHRAE Standard 62.2-2010 – the United States standard for residential ventilation - is used as the chronic standard, and exposure limits for PM2.5, formaldehyde and NO2 are used as the acute standards.The results show that controlled passive ventilation and hybrid ventilation can be used in homes to provide equivalent IAQ to continuous mechanical ventilation, for less use of energy.

  18. Ventilation.

    PubMed

    Turner, W A; Bearg, D W; Brennan, T

    1995-01-01

    This chapter begins with an overview of the history of ventilation guidelines, which has led to the guidelines that are in effect today. Of particular interest is the most recent return in the past 5 years to ventilation rates that more closely reflect a mean or average of the range of guidelines that have existed over the past century. OSHA's and the EPA's recognition of the need to operate ventilation systems in buildings in an accountable manner is also of note. Of even more interest is the resurgence of the concept of minimum mixing and once-through ventilation air that has been pursued in parts of Northern Europe for the past 10 years, and in a school that is being designed with this concept in New Hampshire. In addition, the design concept of equipping office buildings with low pressure drop high efficiency particle filtration to remove fine particles from all of the air that is supplied to the occupants is being used increasingly in the U.S. This chapter also presents an overview of the various types of ventilation systems found in homes and commercial office buildings and the common indoor air quality problems that may be associated with them. It also offers an overview of common HVAC evaluation techniques that can be used to determine if a ventilation system is performing in a manner that makes sense for the use of the space and the needs of the occupants. Are the occupants receiving a reasonable supply of outdoor air? Is the air that they receive of reasonable quality? Are obvious pollutants being exhausted? Ventilation systems have become extremely complex and more difficult to run and maintain over the past 40 years. This trend will continue to drive the need for professionally maintained HVAC equipment that is serviced and run by individuals who are accountable for the quality of the air that the system delivers.

  19. Ventilation efficiencies of a desk-edge-mounted task ventilation system

    SciTech Connect

    Faulkner, David; Fisk, William J.; Sullivan, Douglas P.; Lee, Seung Min

    2002-03-01

    In chamber experiments, we investigated the effectiveness of a task ventilation system with an air supply nozzle located underneath the front edge of a desk and directing air toward a heated mannequin seated at the desk. The task ventilation system provided outside air, while another ventilation system provided additional space cooling but no outside air. Test variables included the vertical angle of air supply (-15{sup o} to 45{sup o} from horizontal), and the supply flow rate of (3.5 to 6.5 L s{sup -1}). Using the tracer gas step-up and step-down procedures, the measured air change effectiveness (i.e., exhaust air age divided by age of air at the mannequin's face) ranged from 1.4 to 2.7, which is higher than typically reported for commercially available task ventilation or displacement ventilation systems.

  20. Use of Disinfectants and Sanitizers in Heating, Ventilation, Air Conditioning, and Refrigeration Systems

    EPA Pesticide Factsheets

    This letter is to brings attention several concerns that the Agency has regarding the use of sanitizer and/or disinfectant products, and other types of antimicrobial products, to treat the surfaces of heating, ventilation

  1. 30 CFR 75.350 - Belt air course ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... except as provided in paragraph (c) of this section. (2) Effective December 31, 2009, the air velocity in... manager may approve lower velocities in the ventilation plan based on specific mine conditions. Air velocities must be compatible with all fire detection systems and fire suppression systems used in the...

  2. 30 CFR 75.350 - Belt air course ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... except as provided in paragraph (c) of this section. (2) Effective December 31, 2009, the air velocity in... manager may approve lower velocities in the ventilation plan based on specific mine conditions. Air velocities must be compatible with all fire detection systems and fire suppression systems used in the...

  3. 30 CFR 75.350 - Belt air course ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... except as provided in paragraph (c) of this section. (2) Effective December 31, 2009, the air velocity in... manager may approve lower velocities in the ventilation plan based on specific mine conditions. Air velocities must be compatible with all fire detection systems and fire suppression systems used in the...

  4. 30 CFR 75.350 - Belt air course ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... except as provided in paragraph (c) of this section. (2) Effective December 31, 2009, the air velocity in... manager may approve lower velocities in the ventilation plan based on specific mine conditions. Air velocities must be compatible with all fire detection systems and fire suppression systems used in the...

  5. Application of local exhaust ventilation system and integrated collectors for control of air pollutants in mining company.

    PubMed

    Ghorbani Shahna, Farshid; Bahrami, Abdulrahman; Farasati, Farhad

    2012-01-01

    Local exhaust ventilation (LEV) systems and integrated collectors were designed and implemented in a mining company in order to control emitted air pollutant from furnaces. The LEV was designed for capture and transition of air pollutants emitted from furnaces to the integrated collectors. The integrated collectors including four high efficiency Stairmand model cyclones for control of particulate matter, a venturi scrubber for control of the fine particles, SO(2) and a part of H(2)S to follow them, and a packed scrubber for treatment of the residual H(2)S and SO(2) were designed. Pollutants concentration were measured to determine system effectiveness. The results showed that the effectiveness of LEV for reducing workplace pollution is 91.83%, 96.32% and 83.67% for dust, SO(2) and H(2)S, respectively. Average removal efficiency of particles by combination of cyclone and venturi scrubber was 98.72%. Average removal efficiency of SO(2) and H(2)S were 95.85% and 47.13% for the venturi scrubber and 68.45% and 92.7% for the packed bed scrubber. The average removal efficiency of SO(2) and H(2)S were increased to 99.1% and 95.95% by the combination of venturi and packed bed scrubbers. According to the results, integrated collectors are a good air pollution control option for industries with economic constraints and ancient technologies.

  6. Indoor Air Quality: Is Increased Ventilation the Answer?

    ERIC Educational Resources Information Center

    Hansen, Shirley

    1989-01-01

    Explains how indoor air quality is affected by pollutants in the air and also by temperature, humidity, and ventilation. Increased ventilation alone seldom solves the "sick building syndrome." Lists ways to improve indoor air quality and optimize energy efficiency. (MLF)

  7. Capture and Use of Coal Mine Ventilation Air Methane

    SciTech Connect

    Deborah Kosmack

    2008-10-31

    CONSOL Energy Inc., in conjunction with MEGTEC Systems, Inc., and the U.S. Department of Energy with the U.S. Environmental Protection Agency, designed, built, and operated a commercial-size thermal flow reversal reactor (TFRR) to evaluate its suitability to oxidize coal mine ventilation air methane (VAM). Coal mining, and particularly coal mine ventilation air, is a major source of anthropogenic methane emissions, a greenhouse gas. Ventilation air volumes are large and the concentration of methane in the ventilation air is low; thus making it difficult to use or abate these emissions. This test program was conducted with simulated coal mine VAM in advance of deploying the technology on active coal mine ventilation fans. The demonstration project team installed and operated a 30,000 cfm MEGTEC VOCSIDIZER oxidation system on an inactive coal mine in West Liberty, WV. The performance of the unit was monitored and evaluated during months of unmanned operation at mostly constant conditions. The operating and maintenance history and how it impacts the implementation of the technology on mine fans were investigated. Emission tests showed very low levels of all criteria pollutants at the stack. Parametric studies showed that the equipment can successfully operate at the design specification limits. The results verified the ability of the TFRR to oxidize {ge}95% of the low and variable concentration of methane in the ventilation air. This technology provides new opportunities to reduce greenhouse gas emissions by the reduction of methane emissions from coal mine ventilation air. A large commercial-size installation (180,000 cfm) on a single typical mine ventilation bleeder fan would reduce methane emissions by 11,000 to 22,100 short tons per year (the equivalent of 183,000 to 366,000 metric tonnes carbon dioxide).

  8. 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.

  9. How to Plan Ventilation Systems.

    ERIC Educational Resources Information Center

    Clarke, John H.

    1963-01-01

    Ventilation systems for factory safety demand careful planning. The increased heat loads and new processes of industry have introduced complex ventilation problems in--(1) ventilation supply, (2) duct work design, (3) space requirements, (4) hood face velocities, (5) discharge stacks, and (6) building eddies. This article describes and diagrams…

  10. The correlation of Acanthamoeba from the ventilation system with other environmental parameters in commercial buildings as possible indicator for indoor air quality

    PubMed Central

    OOI, Soo Shen; MAK, Joon Wah; CHEN, Donald K.F.; AMBU, Stephen

    2016-01-01

    The free-living protozoan Acanthamoeba is an opportunistic pathogen that is ubiquitous in our environment. However, its role in affecting indoor air quality and ill-health of indoor occupants is relatively unknown. The present study investigated the presence of Acanthamoeba from the ventilation system and its correlation with other indoor air quality parameters, used in the industry code of practice and its potential as an indicator for indoor air quality. Indoor air quality assessments were carried out in nine commercial buildings with approval from the building management, and the parameters assessed were as recommended by the Department of Occupational Safety and Health. The presence of Acanthamoeba was determined through dust swabs from the ventilation system and indoor furniture. Logistic regression was performed to study the correlation between assessed parameters and occupants’ complaints. A total of 107 sampling points were assessed and 40.2% of the supplying air diffuser and blowing fan and 15% of the furniture were positive for cysts. There was a significant correlation between Acanthamoeba detected from the ventilation system with ambient total fungus count (r=0.327; p=0.01) and respirable particulates (r=0.276; p=0.01). Occupants’ sick building syndrome experience also correlated with the presence of Acanthamoeba in the ventilation system (r=0.361; p=0.01) and those detected on the furniture (r=0.290; p=0.01). Logistic regression showed that there was a five-fold probability of sick building syndrome among occupants when Acanthamoeba was detected in the ventilation system. PMID:27476379

  11. Building ventilation and indoor air quality

    SciTech Connect

    Hollowell, C.D.; Berk, J.V.; Boegel, M.L.; Miksch, R.R.; Nazaroff, W.W.; Traynor, G.W.

    1980-01-01

    Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced infiltration and ventilation in buildings may significantly increase exposure to indoor contaminants and perhaps have adverse effects on occupant health and comfort. Four indoor air contaminants - carbon monoxide and nitrogen dioxide from gas appliances; formaldehyde from particleboard, plywood, urea-formaldehyde foam insulation, and gas appliances; and radon from building materials, soil, and ground water - are currently receiving considerable attention in the context of potential health risks associated with reduced infiltration and ventilation rates. These air contaminants in conventional and energy efficient buildings were measured and analyzed with a view to assessing their potential health risks and various control strategies capable of lowering pollutant concentrations. Preliminary findings suggest that further intensive studies are needed in order to develop criteria for maintaining acceptable indoor air quality without compromising energy efficiency.

  12. Tunnel ventilation system design and management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Properly designed and functioning tunnel ventilation systems in broiler houses are essential for maintaining productivity of broilers in warm weather. Convective heat loss from high air velocity provides cooling which improves performance; however, high air velocities require larger fans and increa...

  13. Development of a Self-Tuning Controller for HVAC (Heating, Ventilating, and Air Conditioning) Systems.

    DTIC Science & Technology

    1985-08-01

    AD-RI69 329 DEVELOPMENT OF A SELF-TUNING CONTROLLER FORR f (HEATING VENTILATING AND.. (U) NARL CIVIL ENGINEERING LAB PORT HUENEME CA R E-KIRTS ET AL...Facilities Engineering Command I PROGRAM NO: Z0371-O1-221B0% ___ NAVAL CIVIL ENGINEERING LABORATORYT C S PORT HUENEME, CALIFORNIA 93043 LLJ Approved for...UITNUBR NAVAL CIVIL ENGINEERING LABORATORY 64710N; Port Hueneme, California 93043 Z0371-01-221B I I CONTROLLING OFFICE NAME AND ADDRESS 12 REPORT DATE Naval

  14. VENTILATION RESEARCH: A REVIEW OF RECENT INDOOR AIR QUALITY LITERATURE

    EPA Science Inventory

    The report gives results of a literature review, conducted to survey and summarize recent and ongoing engineering research into building ventilation, air exchange rate, pollutant distribution and dispersion, and other effects of heating, ventilation, and air-conditioning (HVAC) s...

  15. Surveillance of a Ventilated Rack System for Corynebacterium bovis by Sampling Exhaust-Air Manifolds.

    PubMed

    Manuel, Christopher A; Pugazhenthi, Umarani; Leszczynski, Jori K

    2016-01-01

    Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks' air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection.

  16. Surveillance of a Ventilated Rack System for Corynebacterium bovis by Sampling Exhaust-Air Manifolds

    PubMed Central

    Manuel, Christopher A; Pugazhenthi, Umarani; Leszczynski, Jori K

    2016-01-01

    Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks’ air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection. PMID:26817981

  17. WASTE HANDLING BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    P.A. Kumar

    2000-06-21

    The Waste Handling Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Handling Building (WHB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for equipment operation and personnel comfort, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WHB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement areas ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination within the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WHB. The Waste Handling Building Ventilation System is designed to perform its safety functions under accident conditions and other Design Basis Events (DBEs) (such as earthquakes, tornadoes, fires, and loss of the primary electric power). Additional system design features (such as compartmentalization with independent subsystems) limit the potential for cross-contamination within the WHB. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Handling Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits. The system design, operations, and maintenance activities incorporate ALARA (as low as is

  18. Are Ventilation Filters Degrading Indoor Air Quality in California Classrooms?

    SciTech Connect

    Fisk, William J.; Destaillats, H.; Apte, M.G.; Destaillats,, Hugo; Fisk, Michael G. Apte and William J.

    2008-10-01

    Heating, ventilating, and cooling classrooms in California consume substantial electrical energy. Indoor air quality (IAQ) in classrooms affects studenthealth and performance. In addition to airborne pollutants that are emitted directly by indoor sources and those generated outdoors, secondary pollutants can be formed indoors by chemical reaction of ozone with other chemicals and materials. Filters are used in nearly all classroom heating, ventilation and air?conditioning (HVAC) systems to maintain energy-efficient HVAC performance and improve indoor air quality; however, recent evidence indicates that ozone reactions with filters may, in fact, be a source of secondary pollutants. This project quantitatively evaluated ozone deposition in HVAC filters and byproduct formation, and provided a preliminary assessment of the extent towhich filter systems are degrading indoor air quality. The preliminary information obtained will contribute to the design of subsequent research efforts and the identification of energy efficient solutions that improve indoor air quality in classrooms and the health and performance of students.

  19. Analysis of Air Flow in the Ventilated Insulating Air Layer of the External Wall

    NASA Astrophysics Data System (ADS)

    Katunská, Jana; Bullová, Iveta; Špaková, Miroslava

    2016-12-01

    The paper deals with problems of impact of air flow in ventilated insulating air layer of the external wall on behaviour of thermal-technical parameters of the proposed external structure (according principles of STN 73 0549, which is not valid now), by comparing them in the calculation according to the valid STN standards, where air flow in the ventilated air layer is not taken into account, as well as by comparing them with behavior of thermal-technical parameters in the proposal of sandwich external wall with the contact heat insulation system without air cavity.

  20. Ventilation efficiencies and thermal comfort results of a desk-edge-mounted task ventilation system

    SciTech Connect

    Faulkner, D.; Fisk, W.J.; Sullivan, D.P.; Lee, S.M.

    2003-09-01

    In chamber experiments, we investigated the ventilation effectiveness and thermal comfort of a task ventilation system with an air supply nozzle located underneath the front edge of a desk and directing air toward a heated mannequin or a human volunteer seated at the desk. The task ventilation system provided outside air, while another ventilation system provided additional space cooling but no outside air. Test variables included the vertical angle of air supply (-15{sup o} to 45{sup o} from horizontal), and the supply flow rate of (3.5 to 6.5 L s{sup -1}). Using the tracer gas step-up and step-down procedures, the measured air change effectiveness (i.e., exhaust air age divided by age of air in the breathing zone) in experiments with the mannequin ranged from 1.4 to 2.7 (median, 1.8), whereas with human subjects the air change effectiveness ranged from 1.3 to 2.3 (median, 1.6). The majority of the air change effectiveness values with the human subjects were less than values with the mannequin at comparable tests. Similarly, the tests run with supply air temperature equal to the room air temperature had lower air change effectiveness values than comparable tests with the supply air temperature lower ({approx}5 C) than the room air temperature. The air change effectiveness values are higher than typically reported for commercially available task ventilation or displacement ventilation systems. Based on surveys completed by the subjects, operation of the task ventilation system did not cause thermal discomfort.

  1. Demand Controlled Economizer Cycles: A Direct Digital Control Scheme for Heating, Ventilating, and Air Conditioning Systems,

    DTIC Science & Technology

    1984-05-01

    includes a heating coil and thermostatic control to maintain the air in this path at an elevated temperature, typically around 80 degrees Farenheit (80 F...1238 Aug 1 1236 1237 52 1074 1126 50 1033 1083 Sep 8 8 5W 862 7T 600 678 75 603 7r Oct 51 400 451 119 204 323 115 207 322 ov 64 123 287 187 71 258

  2. Preoperational test report, recirculation ventilation systems

    SciTech Connect

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  3. Energy Savings Potential and Research, Development, & Demonstration Opportunities for Residential Building Heating, Ventilation, and Air Conditioning Systems

    SciTech Connect

    Goetzler, William; Zogg, Robert; Young, Jim; Schmidt, Justin

    2012-10-01

    This report is an assessment of 135 different heating, ventilation, and air-conditioning (HVAC) technologies for U.S. residential buildings to identify and provide analysis on 19 priority technology options in various stages of development. The analyses include an estimation of technical energy-savings potential, descriptions of technical maturity, descriptions of non-energy benefits, descriptions of current barriers for market adoption, and descriptions of the technology's applicability to different building or HVAC equipment types. From these technology descriptions, are suggestions for potential research, development and demonstration (RD&D) initiatives that would support further development of the priority technology options.

  4. Energy Savings Potential and Research, Development, & Demonstration Opportunities for Commercial Building Heating, Ventilation, and Air Conditioning Systems

    SciTech Connect

    none,

    2011-09-01

    This report covers an assessment of 182 different heating, ventilation, and air-conditioning (HVAC) technologies for U.S. commercial buildings to identify and provide analysis on 17 priority technology options in various stages of development. The analyses include an estimation of technical energy-savings potential, description of technical maturity, description of non-energy benefits, description of current barriers for market adoption, and description of the technology’s applicability to different building or HVAC equipment types. From these technology descriptions, are suggestions for potential research, development and demonstration (RD&D) initiatives that would support further development of the priority technology options.

  5. Summarized Data of Test Space Heating, Ventilation and Air Conditioning Inspections from the Building Assessment Survey and Evaluation Study

    EPA Pesticide Factsheets

    Information on the characteristics of the heating, ventilation, and air conditioning (HVAC) system(s) in the entire BASE building including types of ventilation, equipment configurations, and operation and maintenance issues

  6. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111.103-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Power ventilation systems except machinery space ventilation systems. Each power ventilation system...

  7. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111.103-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Power ventilation systems except machinery space ventilation systems. Each power ventilation system...

  8. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111.103-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Power ventilation systems except machinery space ventilation systems. Each power ventilation system...

  9. PI Control of a Single-Duct VAV (Variable Air Volume) HVAC (Heating, Ventilating, and Air Conditioning) System.

    DTIC Science & Technology

    1985-06-01

    and Subtitle) S. TYPE OF REPORT & PERIOD COVERED PI CONTROL OF A SINGLE-DUCT VAV HVAC SYSTEM FINAL 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(s) S...only remaining facet of the - design is the selection of the two PI controller gain values: the propor- tional control gain K and the integral control...gain K1. These values will be p ’. . obtained once the PI controller is attached to the plant by using the pro- cedure devised by J. C. Ziegler and N. B

  10. Indoor Air Quality and Ventilation in Residential Deep Energy Retrofits

    SciTech Connect

    Less, Brennan; Walker, Iain

    2014-06-01

    Because airtightening is a significant part of Deep Energy Retrofits (DERs), concerns about ventilation and Indoor Air Quality (IAQ) have emerged. To investigate this, ventilation and IAQ were assessed in 17 non-smoking California Deep Energy Retrofit homes. Inspections and surveys were used to assess household activities and ventilation systems. Pollutant sampling performed in 12 homes included six-day passive samples of nitrogen dioxide (NO2), formaldehyde and air exchange rate (AER); time-resolved data loggers were used to measure particle counts. Half of the homes provided continuous mechanical ventilation. Despite these homes being twice as airtight (3.0 and 7.6 ACH50, respectively), their median AER was indistinguishable from naturally vented homes (0.36 versus 0.37 hr-1). Numerous problems were found with ventilation systems; however, pollutant levels did not reach levels of concern in most homes. Ambient NO2 standards were exceeded in some gas cooking homes that used legacy ranges with standing pilots, and in Passive House-style homes without range hoods exhausted to outside. Cooking exhaust systems were installed and used inconsistently. The majority of homes reported using low-emitting materials, and formaldehyde levels were approximately half those in conventional new CA homes (19.7 versus 36 μg/m3), with emissions rates nearly 40percent less (12.3 versus 20.6 μg/m2/hr.). Presence of air filtration systems led to lower indoor particle number concentrations (PN>0.5: 8.80E+06 PN/m3 versus 2.99E+06; PN>2.5: 5.46E+0.5 PN/m3 versus 2.59E+05). The results indicate that DERs can provide adequate ventilation and IAQ, and that DERs should prioritize source control, particle filtration and well-designed local exhaust systems, while still providing adequate continuous ventilation.

  11. Ventilation Systems Operating Experience Review for Fusion Applications

    SciTech Connect

    L. C. Cadwallader

    1999-12-01

    This report is a collection and review of system operation and failure experiences for air ventilation systems in nuclear facilities. These experiences are applicable for magnetic and inertial fusion facilities since air ventilation systems are support systems that can be considered generic to nuclear facilities. The report contains descriptions of ventilation system components, operating experiences with these systems, component failure rates, and component repair times. Since ventilation systems have a role in mitigating accident releases in nuclear facilities, these data are useful in safety analysis and risk assessment of public safety. An effort has also been given to identifying any safety issues with personnel operating or maintaining ventilation systems. Finally, the recommended failure data were compared to an independent data set to determine the accuracy of individual values. This comparison is useful for the International Energy Agency task on fusion component failure rate data collection.

  12. Hygiene guideline for the planning, installation, and operation of ventilation and air-conditioning systems in health-care settings - Guideline of the German Society for Hospital Hygiene (DGKH).

    PubMed

    Külpmann, Rüdiger; Christiansen, Bärbel; Kramer, Axel; Lüderitz, Peter; Pitten, Frank-Albert; Wille, Frank; Zastrow, Klaus-Dieter; Lemm, Friederike; Sommer, Regina; Halabi, Milo

    2016-01-01

    Since the publication of the first "Hospital Hygiene Guideline for the implementation and operation of air conditioning systems (HVAC systems) in hospitals" (http://www.krankenhaushygiene.de/informationen/fachinformationen/leitlinien/12) in 2002, it was necessary due to the increase in knowledge, new regulations, improved air-conditioning systems and advanced test methods to revise the guideline. Based on the description of the basic features of ventilation concepts, its hygienic test and the usage-based requirements for ventilation, the DGKH section "Ventilation and air conditioning technology" attempts to provide answers for the major air quality issues in the planning, design and the hygienically safe operation of HVAC systems in rooms of health care.

  13. Hygiene guideline for the planning, installation, and operation of ventilation and air-conditioning systems in health-care settings – Guideline of the German Society for Hospital Hygiene (DGKH)

    PubMed Central

    Külpmann, Rüdiger; Christiansen, Bärbel; Kramer, Axel; Lüderitz, Peter; Pitten, Frank-Albert; Wille, Frank; Zastrow, Klaus-Dieter; Lemm, Friederike; Sommer, Regina; Halabi, Milo

    2016-01-01

    Since the publication of the first “Hospital Hygiene Guideline for the implementation and operation of air conditioning systems (HVAC systems) in hospitals” (http://www.krankenhaushygiene.de/informationen/fachinformationen/leitlinien/12) in 2002, it was necessary due to the increase in knowledge, new regulations, improved air-conditioning systems and advanced test methods to revise the guideline. Based on the description of the basic features of ventilation concepts, its hygienic test and the usage-based requirements for ventilation, the DGKH section “Ventilation and air conditioning technology” attempts to provide answers for the major air quality issues in the planning, design and the hygienically safe operation of HVAC systems in rooms of health care. PMID:26958457

  14. Energy and air quality implications of passive stack ventilation in residential buildings

    SciTech Connect

    Mortensen, Dorthe Kragsig; Walker, Iain S.; Sherman, Max

    2011-01-01

    Ventilation requires energy to transport and condition the incoming air. The energy consumption for ventilation in residential buildings depends on the ventilation rate required to maintain an acceptable indoor air quality. Historically, U.S. residential buildings relied on natural infiltration to provide sufficient ventilation, but as homes get tighter, designed ventilation systems are more frequently required particularly for new energy efficient homes and retrofitted homes. ASHRAE Standard 62.2 is used to specify the minimum ventilation rate required in residential buildings and compliance is normally achieved with fully mechanical whole-house systems; however, alternative methods may be used to provide the required ventilation when their air quality equivalency has been proven. One appealing method is the use of passive stack ventilation systems. They have been used for centuries to ventilate buildings and are often used in ventilation regulations in other countries. Passive stacks are appealing because they require no fans or electrical supply (which could lead to lower cost) and do not require maintenance (thus being more robust and reliable). The downside to passive stacks is that there is little control of ventilation air flow rates because they rely on stack and wind effects that depend on local time-varying weather. In this study we looked at how passive stacks might be used in different California climates and investigated control methods that can be used to optimize indoor air quality and energy use. The results showed that passive stacks can be used to provide acceptable indoor air quality per ASHRAE 62.2 with the potential to save energy provided that they are sized appropriately and flow controllers are used to limit over-ventilation.

  15. Advanced Controls for Residential Whole-House Ventilation Systems

    SciTech Connect

    Turner, William; Walker, Iain; Sherman, Max

    2014-08-01

    Whole-house ventilation systems are becoming commonplace in new construction, remodeling/renovation, and weatherization projects, driven by combinations of specific requirements for indoor air quality (IAQ), health and compliance with standards, such as ASHRAE 62.2. Ventilation systems incur an energy penalty on the home via fan power used to drive the airflow, and the additional space-conditioning load associated with heating or cooling the ventilation air. Finding a balance between IAQ and energy use is important if homes are to be adequately ventilated while not increasing the energy burden. This study used computer simulations to examine RIVEC the Residential Integrated Ventilation Controller - a prototype ventilation controller that aims to deliver whole-house ventilation rates that comply with ventilation standards, for the minimum use of energy. Four different whole-house ventilation systems were simulated, both with and without RIVEC, so that the energy and IAQ results could be compared. Simulations were conducted for 13 US climate zones, three house designs, and three envelope leakage values. The results showed that the RIVEC controller could typically return ventilation energy savings greater than 40percent without compromising long-term chronic or short-term acute exposures to relevant indoor contaminants. Critical and average peak power loads were also reduced as a consequence of using RIVEC.

  16. Evolution of microbial aerosol behaviour in heating, ventilating and air-conditioning systems--quantification of Staphylococcus epidermidis and Penicillium oxalicum viability.

    PubMed

    Forthomme, A; Andrès, Y; Joubert, A; Simon, X; Duquenne, P; Bemer, D; Le Coq, L

    2013-01-01

    The aim of this study was to develop an experimental set-up and a methodology to uniformly contaminate several filter samples with high concentrations of cultivable bacteria and fungi. An experimental set-up allows contaminating simultaneously up to four filters for range of velocities representative of heating, ventilating and air-conditioning systems. The test aerosol was composed of a microbial consortium of one bacterium (Staphylococcus epidermidis) and one fungus (Penicillium oxalicum) and aerosol generation was performed in wet conditions. Firstly, the experimental set-up was validated in regards to homogeneity of the air flows. The bioaerosol was also characterized in terms of number and particle size distribution using two particle counters: optical particle counter Grimm 1.109 (optical diameters) and TSI APS 3321 (aerodynamic diameters). Moreover, stabilities of the number of particles generated were measured. Finally, concentrations of cultivable microorganisms were measured with BioSamplers (SKC) downstream of the four filters.

  17. Evolution of microbial aerosol behaviour in heating, ventilating and air-conditioning systems--quantification of Staphylococcus epidermidis and Penicillium oxalicum viability.

    PubMed

    Forthomme, A; Andrès, Y; Joubert, A; Simon, X; Duquenne, P; Bemer, D; Le Coq, L

    2012-01-01

    The aim of this study was to develop an experimental set-up and a methodology to uniformly contaminate several filter samples with high concentrations of cultivable bacteria and fungi. An experimental set-up allows contaminating simultaneously up to four filters for range of velocities representative of heating, ventilating and air-conditioning systems. The test aerosol was composed of a microbial consortium of one bacterium (Staphylococcus epidermidis) and one fungus (Penicillium oxalicum) and aerosol generation was performed in wet conditions. Firstly, the experimental set-up was validated in regards to homogeneity of the air flows. The bioaerosol was also characterized in terms of the number and particle size distribution using two particle counters: optical particle counter Grimm 1.109 (optical diameters) and TSI APS 3321 (aerodynamic diameters). Moreover, stabilities of the number of particles generated were measured. Finally, concentrations of cultivable microorganisms were measured with BioSamplers SKC downstream of the four filters.

  18. Measure Guideline: Selecting Ventilation Systems for Existing Homes

    SciTech Connect

    Aldrich, R.

    2014-02-01

    This document addresses adding -or improving - mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards. Advantages, disadvantages, and approximate costs of various system types are presented along with general guidelines for implementing the systems in homes. CARB intends for this document to be useful to decision makers and contractors implementing ventilation systems in homes. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors. It is the intent of this document to assist contractors in making more informed decisions when selecting systems. Ventilation is an integral part of a high-performance home. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability.

  19. New Air Cleaning Strategies for Reduced Commercial Building Ventilation Energy ? FY11 Final Report

    SciTech Connect

    Sidheswaran, Meera; Destaillats, Hugo; Cohn, Sebastian; Sullivan, Douglas P.; Fisk, William J.

    2011-10-31

    The research carried out in this project focuses on developing novel volatile organic compounds (VOCs) air cleaning technologies needed to enable energy-saving reductions in ventilation rates. we targeted a VOC air cleaning system that could enable a 50% reduction in ventilation rates. In a typical commercial HVAC system that provides a mixture of recirculated and outdoor air, a VOC air cleaner in the supply airstream must have a 15% to 20% VOC removal efficiency to counteract a 50% reduction in outdoor air supply.

  20. Power turbine ventilation system

    NASA Technical Reports Server (NTRS)

    Wakeman, Thomas G. (Inventor); Brown, Richard W. (Inventor)

    1991-01-01

    Air control mechanism within a power turbine section of a gas turbine engine. The power turbine section includes a rotor and at least one variable pitch propulsor blade. The propulsor blade is coupled to and extends radially outwardly of the rotor. A first annular fairing is rotatable with the propulsor blade and interposed between the propulsor blade and the rotor. A second fairing is located longitudinally adjacent to the first fairing. The first fairing and the second fairing are differentially rotatable. The air control mechanism includes a platform fixedly coupled to a radially inner end of the propulsor blade. The platform is generally positioned in a first opening and a first fairing. The platform and the first fairing define an outer space. In a first position corresponding with a first propulsor blade pitch, the platform is substantially conformal with the first fairing. In a second position corresponding with the second propulsor blade pitch, an edge portion of the platform is displaced radially outwardly from the first fairing. When the blades are in the second position and rotating about the engine axis, the displacement of the edge portion with respect to the first fairing allows air to flow from the outer space to the annular cavity.

  1. Mechanical ventilation and lung infection in the genesis of air-space enlargement

    PubMed Central

    Sartorius, Alfonso; Lu, Qin; Vieira, Silvia; Tonnellier, Marc; Lenaour, Gilles; Goldstein, Ivan; Rouby, Jean-Jacques

    2007-01-01

    Introduction Air-space enlargement may result from mechanical ventilation and/or lung infection. The aim of this study was to assess how mechanical ventilation and lung infection influence the genesis of bronchiolar and alveolar distention. Methods Four groups of piglets were studied: non-ventilated-non-inoculated (controls, n = 5), non-ventilated-inoculated (n = 6), ventilated-non-inoculated (n = 6), and ventilated-inoculated (n = 8) piglets. The respiratory tract of intubated piglets was inoculated with a highly concentrated solution of Escherichia coli. Mechanical ventilation was maintained during 60 hours with a tidal volume of 15 ml/kg and zero positive end-expiratory pressure. After sacrifice by exsanguination, lungs were fixed for histological and lung morphometry analyses. Results Lung infection was present in all inoculated piglets and in five of the six ventilated-non-inoculated piglets. Mean alveolar and mean bronchiolar areas, measured using an analyzer computer system connected through a high-resolution color camera to an optical microscope, were significantly increased in non-ventilated-inoculated animals (+16% and +11%, respectively, compared to controls), in ventilated-non-inoculated animals (+49% and +49%, respectively, compared to controls), and in ventilated-inoculated animals (+95% and +118%, respectively, compared to controls). Mean alveolar and mean bronchiolar areas significantly correlated with the extension of lung infection (R = 0.50, p < 0.01 and R = 0.67, p < 0.001, respectively). Conclusion Lung infection induces bronchiolar and alveolar distention. Mechanical ventilation induces secondary lung infection and is associated with further air-space enlargement. The combination of primary lung infection and mechanical ventilation markedly increases air-space enlargement, the degree of which depends on the severity and extension of lung infection. PMID:17274806

  2. 21 CFR 211.46 - Ventilation, air filtration, air heating and cooling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Ventilation, air filtration, air heating and cooling. 211.46 Section 211.46 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a)...

  3. 21 CFR 211.46 - Ventilation, air filtration, air heating and cooling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Ventilation, air filtration, air heating and cooling. 211.46 Section 211.46 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a)...

  4. 21 CFR 211.46 - Ventilation, air filtration, air heating and cooling.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Ventilation, air filtration, air heating and cooling. 211.46 Section 211.46 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a)...

  5. 21 CFR 211.46 - Ventilation, air filtration, air heating and cooling.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Ventilation, air filtration, air heating and cooling. 211.46 Section 211.46 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a)...

  6. Neonatal air leak syndrome and the role of high-frequency ventilation in its prevention.

    PubMed

    Jeng, Mei-Jy; Lee, Yu-Sheng; Tsao, Pei-Chen; Soong, Wen-Jue

    2012-11-01

    Air leak syndrome includes pulmonary interstitial emphysema, pneumothorax, pneumomediastinum, pneumopericardium, pneumoperitoneum, subcutaneous emphysema, and systemic air embolism. The most common cause of air leak syndrome in neonates is inadequate mechanical ventilation of the fragile and immature lungs. The incidence of air leaks in newborns is inversely related to the birth weight of the infants, especially in very-low-birth-weight and meconium-aspirated infants. When the air leak is asymptomatic and the infant is not mechanically ventilated, there is usually no specific treatment. Emergent needle aspiration and/or tube drainage are necessary in managing tension pneumothorax or pneumopericardium with cardiac tamponade. To prevent air leak syndrome, gentle ventilation with low pressure, low tidal volume, low inspiratory time, high rate, and judicious use of positive end expiratory pressure are the keys to caring for mechanically ventilated infants. Both high-frequency oscillatory ventilation (HFOV) and high-frequency jet ventilation (HFJV) can provide adequate gas exchange using extremely low tidal volume and supraphysiologic rate in neonates with acute pulmonary dysfunction, and they are considered to have the potential to reduce the risks of air leak syndrome in neonates. However, there is still no conclusive evidence that HFOV or HFJV can help to reduce new air leaks in published neonatal clinical trials. In conclusion, neonatal air leaks may present as a thoracic emergency requiring emergent intervention. To prevent air leak syndrome, gentle ventilations are key to caring for ventilated infants. There is insufficient evidence showing the role of HFOV and HFJV in the prevention or reduction of new air leaks in newborn infants, so further investigation will be necessary for future applications.

  7. Effectiveness of in-room air filtration and dilution ventilation for tuberculosis infection control

    SciTech Connect

    Miller-Leiden, S.; Lobascio, C.; Nazaroff, W.W.; Macher, J.M.

    1996-09-01

    Tuberculosis (TB) is a public health problem that may pose substantial risks to health care workers and others. TB infection occurs by inhalation of airborne bacteria emitted by persons with active disease. We experimentally evaluated the effectiveness of in-room air filtration systems, specifically portable air filters (PAFs) and ceiling-mounted air filters (CMAFs), in conjunction with dilution ventilation, for controlling TB exposure in high-risk settings. For each experiment, a test aerosol was continuously generated and released into a full-sized room. With the in-room air filter and room ventilation system operating, time-averaged airborne particle concentrations were measured at several points. The effectiveness of in-room air filtration plus ventilation was determined by comparing particle concentrations with and without device operation. The four PAFs and three CMAFs we evaluated reduced room-average particle concentrations, typically by 30% to 90%, relative to a baseline scenario with two air-changes per hour of ventilation (outside air) only. Increasing the rate of air flow recirculating through the filter and/or air flow from the ventilation did not always increase effectiveness. Concentrations were generally higher near the emission source than elsewhere in the room. Both the air flow configuration of the filter and its placement within the room were important. 46 refs., 12 figs., 1 tab.

  8. 30 CFR 36.45 - Quantity of ventilating air.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., AND APPROVAL OF MINING PRODUCTS APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT Test Requirements § 36.45 Quantity of ventilating air. (a) Results of the engine...

  9. Short-term airing by natural ventilation - modeling and control strategies.

    PubMed

    Perino, M; Heiselberg, P

    2009-10-01

    The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. This kind of system frequently integrates traditional mechanical ventilation components with natural ventilation devices, such as motorized windows and louvers. Among the various ventilation strategies that are currently available, buoyancy driven single-sided natural ventilation has proved to be very effective and can provide high air change rates for temperature and IAQ control. However, in order to promote a wider applications of these systems, an improvement in the knowledge of their working principles and the availability of new design and simulation tools is necessary. In this context, the paper analyses and presents the results of a research that was aimed at developing and validating numerical models for the analysis of buoyancy driven single-sided natural ventilation systems. Once validated, these models can be used to optimize control strategies in order to achieve satisfactory indoor comfort conditions and IAQ. Practical Implications Numerical and experimental analyses have proved that short-term airing by intermittent ventilation is an effective measure to satisfactorily control IAQ. Different control strategies have been investigated to optimize the capabilities of the systems. The proposed zonal model has provided good performances and could be adopted as a design tool, while CFD simulations can be profitably used for detailed studies of the pollutant concentration distribution in a room and to address local discomfort problems.

  10. The influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation.

    NASA Astrophysics Data System (ADS)

    Fišer, J.; Jícha, M.

    2013-04-01

    The paper deals with instigation of influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation. CFD approach was used for investigation and model geometry was based on small aircraft cabin mock-up geometry. Model was also equipped by nine seats and five manikins that represent passengers. The air jet direction was observed for selected ambient environment parameters and several types of air duct geometry and influence of main air duct geometry on jets direction is discussed. The model was created in StarCCM+ ver. 6.04.014 software and polyhedral mesh was used.

  11. Residential ventilation with heat recovery: Improving indoor air quality and saving energy

    NASA Astrophysics Data System (ADS)

    Roseme, G. D.; Berk, J. V.; Boegel, M. L.; Halsey, H. I.; Hollowell, C. D.; Rosenfeld, A. H.; Turiel, I.

    1980-05-01

    Residential air quality measurements were made and the use of mechanical ventilation systems with air-to-air heat exchangers is discussed as a promising means of pollutant control. A particular advantage of this control strategy is that the heat exchanger permits recovery of a large portion of the heat that would normally be lost in a simple exhaust ventilation system, and therefore maintains the energy efficiency of the house. An economic analysis is presented showing that installation of these systems in newly constructed homes is cost effective in most regions of the country.

  12. Air Distribution Effectiveness for Residential Mechanical Ventilation: Simulation and Comparison of Normalized Exposures

    SciTech Connect

    Petithuguenin, T.D.P.; Sherman, M.H.

    2009-05-01

    The purpose of ventilation is to dilute indoor contaminants that an occupant is exposed to. Even when providing the same nominal rate of outdoor air, different ventilation systems may distribute air in different ways, affecting occupants' exposure to household contaminants. Exposure ultimately depends on the home being considered, on source disposition and strength, on occupants' behavior, on the ventilation strategy, and on operation of forced air heating and cooling systems. In any multi-zone environment dilution rates and source strengths may be different in every zone and change in time, resulting in exposure being tied to occupancy patterns.This paper will report on simulations that compare ventilation systems by assessing their impact on exposure by examining common house geometries, contaminant generation profiles, and occupancy scenarios. These simulations take into account the unsteady, occupancy-tied aspect of ventilation such as bathroom and kitchen exhaust fans. As most US homes have central HVAC systems, the simulation results will be used to make appropriate recommendations and adjustments for distribution and mixing to residential ventilation standards such as ASHRAE Standard 62.2.This paper will report on work being done to model multizone airflow systems that are unsteady and elaborate the concept of distribution matrix. It will examine several metrics for evaluating the effect of air distribution on exposure to pollutants, based on previous work by Sherman et al. (2006).

  13. Indoor air flow and pollutant removal in a room with desk-top ventilation

    SciTech Connect

    Faulkner, D.; Fisk, W.J.; Sullivan, D.P.

    1993-04-01

    In a furnished experimental facility with three workstations separated by partitions, we studied indoor air flow patterns and tobacco smoke removal efficiency of a desk-top task ventilation system. The task ventilation system permits occupant control of the temperature, flow rate and direction of air supplied through two desk-mounted supply nozzles. In the configuration evaluated, air exited the ventilated space through a ceiling-mounted return grill. To study indoor air flow patterns, we measured the age of air at multiple indoor locations using the tracer gas step-up procedure. To study the intra-room transport of tobacco smoke particles and the efficiency of panicle removal by ventilation, a cigarette was smoked mechanically in one workstation and particle concentrations were measured at multiple indoor locations including the exhaust airstream. Test variables included the direction of air supply from the nozzles, supply nozzle area, supply flow rate and temperature, percent recirculation of chamber air, and internal heatloads. With nozzles pointed toward the occupants, 100% outside air supplied at the desk-top, and air supply rates of approximately 40 L/s per workstation, the age of air at the breathing level of ventilated workstations was approximately 30% less than the age of air that would occur throughout the test space with perfectly mixed indoor air. With smaller air supply rates and/or air supplied parallel to the edges of the desk, ages of air at breathing locations were not significantly lower than the age with perfect mixing. Indoor tobacco smoke particle concentrations at specific locations were generally within 12% of the average measured indoor concentration and concentrations of particles in the exhaust airstream were not significantly different from concentration of particles at breathing locations.

  14. An air curtain in the doorway of a ventilated space

    NASA Astrophysics Data System (ADS)

    Frank, Daria; Linden, Paul

    2013-11-01

    Air curtains are used to reduce the heat and the mass exchange between the indoor environment and the ambient. Their sealing ability is assessed in terms of the effectiveness E, the fraction of the exchange flow prevented by the air curtain compared to the open-door situation. Previous work studied the air curtain effectiveness when the doorway is the only means of ventilating a space. In this talk we examine effects of an additional displacement ventilation pathway on the effectiveness. The main controlling parameter is the deflection modulus Dm which is the ratio between the momentum flux of the air curtain and the transverse forces due to the displacement ventilation. For small values of Dm the air curtain is drawn inside the space by the ventilation flow. For high values of Dm the flow is controlled by the air curtain. A smooth transition occurs between these two regimes and we estimate the Dm value for the onset of this transition. Our model makes a quantitative prediction of E (Dm) in the ventilation-driven regime, and explains qualitatively the shape of the curve in the other two regimes. Laboratory experiments were conducted to test the proposed model. The experimental data were compared to theoretical predictions and good agreement was found.

  15. Methods to reduce the CO(2) concentration of educational buildings utilizing internal ventilation by transferred air.

    PubMed

    Kalema, T; Viot, M

    2014-02-01

    The aim of this study is to develop internal ventilation by transferred air to achieve a good indoor climate with low energy consumption in educational buildings with constant air volume (CAV) ventilation. Both measurements of CO2 concentration and a multi-room calculation model are presented. The study analyzes how to use more efficiently the available spaces and the capacity of CAV ventilation systems in existing buildings and the impact this has on the indoor air quality and the energy consumption of the ventilation. The temperature differences can be used to create natural ventilation airflows between neighboring spaces. The behavior of temperature-driven airflows between rooms was studied and included in the calculation model. The effect of openings between neighboring spaces, such as doors or large apertures in the walls, on the CO2 concentration was studied in different classrooms. The air temperatures and CO2 concentrations were measured using a wireless, internet-based measurement system. The multi-room calculation model predicted the CO2 concentration in the rooms, which was then compared with the measured ones. Using transferred air between occupied and unoccupied spaces can noticeably reduce the total mechanical ventilation rates needed to keep a low CO2 concentration.

  16. 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…

  17. Preoperational test report, primary ventilation system

    SciTech Connect

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Primary Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space filtered venting of tanks AY101, AY102, AZ101, AZ102. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  18. 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…

  19. Measure Guideline: Selecting Ventilation Systems for Existing Homes

    SciTech Connect

    Aldrich, R.

    2014-02-01

    This report, developed by Building America research team CARB, addresses adding or improving mechanical ventilation systems to existing homes. The goal of this report is to assist decision makers and contractors in making informed decisions when selecting ventilation systems for homes. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including examination of relevant codes and standards. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors.

  20. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... not apply to closed ventilation systems for motors or generators, diffuser fans for refrigerated... 46 Shipping 4 2011-10-01 2011-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111.103-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...

  1. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... not apply to closed ventilation systems for motors or generators, diffuser fans for refrigerated... 46 Shipping 4 2010-10-01 2010-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111.103-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...

  2. Commissioning Ventilated Containment Systems in the Laboratory

    SciTech Connect

    Not Available

    2008-08-01

    This Best Practices Guide focuses on the specialized approaches required for ventilated containment systems, understood to be all components that drive and control ventilated enclosures and local exhaust systems within the laboratory. Geared toward architects, engineers, and facility managers, this guide provides information about technologies and practices to use in designing, constructing, and operating operating safe, sustainable, high-performance laboratories.

  3. Indoor airborne bacterial communities are influenced by ventilation, occupancy, and outdoor air source

    PubMed Central

    Meadow, J F; Altrichter, A E; Kembel, S W; Kline, J; Mhuireach, G; Moriyama, M; Northcutt, D; O'Connor, T K; Womack, A M; Brown, G Z; Green, J L ; Bohannan, B J M

    2014-01-01

    Architects and engineers are beginning to consider a new dimension of indoor air: the structure and composition of airborne microbial communities. A first step in this emerging field is to understand the forces that shape the diversity of bioaerosols across space and time within the built environment. In an effort to elucidate the relative influences of three likely drivers of indoor bioaerosol diversity – variation in outdoor bioaerosols, ventilation strategy, and occupancy load – we conducted an intensive temporal study of indoor airborne bacterial communities in a high-traffic university building with a hybrid HVAC (mechanically and naturally ventilated) system. Indoor air communities closely tracked outdoor air communities, but human-associated bacterial genera were more than twice as abundant in indoor air compared with outdoor air. Ventilation had a demonstrated effect on indoor airborne bacterial community composition; changes in outdoor air communities were detected inside following a time lag associated with differing ventilation strategies relevant to modern building design. Our results indicate that both occupancy patterns and ventilation strategies are important for understanding airborne microbial community dynamics in the built environment. PMID:23621155

  4. Indoor airborne bacterial communities are influenced by ventilation, occupancy, and outdoor air source.

    PubMed

    Meadow, J F; Altrichter, A E; Kembel, S W; Kline, J; Mhuireach, G; Moriyama, M; Northcutt, D; O'Connor, T K; Womack, A M; Brown, G Z; Green, J L; Bohannan, B J M

    2014-02-01

    Architects and engineers are beginning to consider a new dimension of indoor air: the structure and composition of airborne microbial communities. A first step in this emerging field is to understand the forces that shape the diversity of bioaerosols across space and time within the built environment. In an effort to elucidate the relative influences of three likely drivers of indoor bioaerosol diversity - variation in outdoor bioaerosols, ventilation strategy, and occupancy load - we conducted an intensive temporal study of indoor airborne bacterial communities in a high-traffic university building with a hybrid HVAC (mechanically and naturally ventilated) system. Indoor air communities closely tracked outdoor air communities, but human-associated bacterial genera were more than twice as abundant in indoor air compared with outdoor air. Ventilation had a demonstrated effect on indoor airborne bacterial community composition; changes in outdoor air communities were detected inside following a time lag associated with differing ventilation strategies relevant to modern building design. Our results indicate that both occupancy patterns and ventilation strategies are important for understanding airborne microbial community dynamics in the built environment.

  5. Technology Solutions Case Study: Selecting Ventilation Systems for Existing Homes

    SciTech Connect

    2014-12-01

    In multifamily buildings, particularly in the Northeast, exhaust ventilation strategies are the norm as a means of meeting both local exhaust and whole-unit mechanical ventilation rates. The issue of where the "fresh" air is coming from is gaining significance as air-tightness standards for enclosures become more stringent, and the normal leakage paths through the building envelope disappear. Researchers from the Consortium for Advanced Residential Buildings (CARB) found that the majority of high performance, new construction, multifamily housing in the Northeast use one of four general strategies for ventilation: continuous exhaust only with no designated supply or make-up air source, continuous exhaust with ducted make-up air to apartments, continuous exhaust with supply through a make-up air device integral to the unit HVAC, and continuous exhaust with supply through a passive inlet device, such as a trickle vent. Insufficient information is available to designers on how these various systems are best applied. In this project, the CARB team evaluated the four different strategies for providing make-up air to multifamily residential buildings and developed guidelines to help contractors and building owners choose the best ventilation systems.

  6. 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.

  7. EFFECT OF VENTILATION SYSTEMS AND AIR FILTERS ON DECAY RATES OF PARTICLES PRODUCED BY INDOOR SOURCES IN AN OCCUPIED TOWNHOUSE

    EPA Science Inventory

    Several studies have shown the importance of particle losses in real homes due to deposition and filtration; however, none have quantitatively shown the impact of using a central forced air fan and in-duct filter on particle loss rates. In an attempt to provide such data, we me...

  8. Assisted Ventilation.

    PubMed

    Dries, David J

    2016-01-01

    Controlled Mechanical Ventilation may be essential in the setting of severe respiratory failure but consequences to the patient including increased use of sedation and neuromuscular blockade may contribute to delirium, atelectasis, and diaphragm dysfunction. Assisted ventilation allows spontaneous breathing activity to restore physiological displacement of the diaphragm and recruit better perfused lung regions. Pressure Support Ventilation is the most frequently used mode of assisted mechanical ventilation. However, this mode continues to provide a monotonous pattern of support for respiration which is normally a dynamic process. Noisy Pressure Support Ventilation where tidal volume is varied randomly by the ventilator may improve ventilation and perfusion matching but the degree of support is still determined by the ventilator. Two more recent modes of ventilation, Proportional Assist Ventilation and Neurally Adjusted Ventilatory Assist (NAVA), allow patient determination of the pattern and depth of ventilation. Proposed advantages of Proportional Assist Ventilation and NAVA include decrease in patient ventilator asynchrony and improved adaptation of ventilator support to changing patient demand. Work of breathing can be normalized with these modes as well. To date, however, a clear pattern of clinical benefit has not been demonstrated. Existing challenges for both of the newer assist modes include monitoring patients with dynamic hyperinflation (auto-positive end expiratory pressure), obstructive lung disease, and air leaks in the ventilator system. NAVA is dependent on consistent transduction of diaphragm activity by an electrode system placed in the esophagus. Longevity of effective support with this technique is unclear.

  9. Assessment of costs and benefits associated with resolution of Generic Safety Issue 143 -- Availability of heating, ventilation, and air conditioning and chilled water systems

    SciTech Connect

    Daling, P.M.; Marler, J.E.; Vo, T.V.; Phan, H.K.; Friley, J.R.

    1995-03-01

    The Pacific Northwest Laboratory, under contract to the US Nuclear Regulatory Commission, has conducted an assessment of the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143--``Availability of Heating, Ventilation, and Air Conditioning (HVAC) and Chilled Water Systems.`` The key objectives of the study were to (a) identify vulnerabilities related to failures of HVAC, chilled water, and room-cooling systems, (b) develop estimates of room heatup rates and safety-related equipment vulnerabilities following losses of HVAC/room-cooler systems, (c) develop estimates of the core damage frequencies and public risks associated with failures of these systems, (d) develop proposed resolution strategies to this generic issue, and (e) perform a value/impact analysis of the proposed resolutions. Detailed probabilistic risk assessments for four representative plants form the basis for the core damage frequency and public risk calculations. Internally initiated core damage sequences as well as external event were considered. Three proposed resolution strategies were developed for this safety issue, and it was determined that all three were not cost effective. Additional evaluations were performed to develop ``generic`` insights on potential design-related vulnerabilities and potential high-frequency (>10{sup {minus}4}/reactor-yr) accident sequences that involve failures of HVAC/room-cooling functions. It was concluded that, although high-frequency accident sequences may exist at some plants, these sequences are plant-specific in nature or have been resolved through hardware and/or operational changes. The plant-specific individual plant examinations appear to be an effective vehicle for identification and resolution of these plant-specific anomalies and hardware configurations.

  10. 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…

  11. Advanced Print Reading. Heating, Ventilation and Air Conditioning.

    ERIC Educational Resources Information Center

    Oregon State Dept. of Education, Salem.

    This is a workbook for students learning advanced blueprint reading for heating, ventilation, and air conditioning applications. The workbook contains eight units covering the following material: architectural working drawings; architectural symbols and dimensions; basic architectural electrical symbols; wiring symbols; basic piping symbols;…

  12. Building America Top Innovations 2012: Outside Air Ventilation Controller

    SciTech Connect

    none,

    2013-01-01

    venThis Building America Top Innovations profile describes Building America research showing how automated night ventilation can reduce cooling energy costs up to 40% and peak demand up to 50% in California’s hot-dry central valley climates and can eliminate the need for air conditioning altogether in the coastal marine climate.

  13. 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…

  14. 46 CFR 153.312 - Ventilation system standards.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... system must meet the following: (a) A ventilation system exhaust duct must discharge no less than 10 m... ventilation duct, a ventilation duct must not pass through a machinery room, an accommodation space,...

  15. Subway platform air quality: Assessing the influences of tunnel ventilation, train piston effect and station design

    NASA Astrophysics Data System (ADS)

    Moreno, T.; Pérez, N.; Reche, C.; Martins, V.; de Miguel, E.; Capdevila, M.; Centelles, S.; Minguillón, M. C.; Amato, F.; Alastuey, A.; Querol, X.; Gibbons, W.

    2014-08-01

    A high resolution air quality monitoring campaign (PM, CO2 and CO) was conducted on differently designed station platforms in the Barcelona subway system under: (a) normal forced tunnel ventilation, and (b) with daytime tunnel ventilation systems shut down. PM concentrations are highly variable (6-128 μgPM1 m-3, 16-314 μgPM3 m-3, and 33-332 μgPM10 m-3, 15-min averages) depending on ventilation conditions and station design. Narrow platforms served by single-track tunnels are heavily dependent on forced tunnel ventilation and cannot rely on the train piston effect alone to reduce platform PM concentrations. In contrast PM levels in stations with spacious double-track tunnels are not greatly affected when tunnel ventilation is switched off, offering the possibility of significant energy savings without damaging air quality. Sampling at different positions along the platform reveals considerable lateral variation, with the greatest accumulation of particulates occurring at one end of the platform. Passenger accesses can dilute PM concentrations by introducing cleaner outside air, although lateral down-platform accesses are less effective than those positioned at the train entry point. CO concentrations on the platform are very low (≤1 ppm) and probably controlled by ingress of traffic-contaminated street-level air. CO2 averages range from 371 to 569 ppm, changing during the build-up and exchange of passengers with each passing train.

  16. Fire protection countermeasures for containment ventilation systems

    SciTech Connect

    Alvares, N.; Beason, D.; Bergman, V.; Creighton, J.; Ford, H.; Lipska, A.

    1980-08-25

    The goal of this project is to find countermeasures to protect High Efficiency Particulate Air (HEPA) filters, in exit ventilation ducts, from the heat and smoke generated by fire. Initially, methods were developed to cool fire-heated air by fine water spray upstream of the filters. It was recognized that smoke aerosol exposure to HEPA filters could also cause disruption of the containment system. Through testing and analysis, several methods to partially mitigate the smoke exposure to the HEPA filters were identified. A continuous, movable, high-efficiency prefilter using modified commercial equipment was designed. The technique is capable of protecting HEPA filters over the total time duration of the test fires. The reason for success involved the modification of the prefiltration media. Commercially available filter media has particle sorption efficiency that is inversely proportional to media strength. To achieve properties of both efficiency and strength, rolling filter media were laminated with the desired properties. The approach was Edisonian, but truncation in short order to a combination of prefilters was effective. The application of this technique was qualified, since it is of use only to protect HEPA filters from fire-generated smoke aerosols. It is not believed that this technique is cost effective in the total spectrum of containment systems, especially if standard fire protection systems are available in the space. But in areas of high-fire risk, where the potential fuel load is large and ignition sources are plentiful, the complication of a rolling prefilter in exit ventilation ducts to protect HEPA filters from smoke aerosols is definitely justified.

  17. Waste tank ventilation system waste material accumulations

    SciTech Connect

    Van Vleet, R.J., Westinghouse Hanford

    1996-08-06

    This paper calculates the amount of material that accumulates in the ventilation systems of various Tank Waste Remediation System facilities and estimates the amount of material that could be released due to a rapid pressurization.

  18. DEMONSTRATION BULLETIN: SUBSURFACE VOLATILIZATION AND VENTILATION SYSTEM - BROWN & ROOT ENVIRONMENTAL

    EPA Science Inventory

    The Subsurface Volatilization and Ventilation System (SVVS*) is an in-situ vacuum extraction/air sparging and bioremediation technology for the treatment of subsurface organic contamination in soil and groundwater. The technology, developed by Billings and Associates, Inc., and o...

  19. Pressure dynamic characteristics of pressure controlled ventilation system of a lung simulator.

    PubMed

    Shi, Yan; Ren, Shuai; Cai, Maolin; Xu, Weiqing; Deng, Qiyou

    2014-01-01

    Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems.

  20. Effect of Room Ventilation Rates in Rodent Rooms with Direct-Exhaust IVC Systems.

    PubMed

    Geertsema, Roger S; Lindsell, Claire E

    2015-09-01

    When IVC are directly exhausted from a rodent housing room, the air quality of the room can become independent of the intracage air quality and may reduce the need for high room ventilation rates. This study assessed the effect of decreasing the ventilation rate in rodent rooms using direct-exhaust IVC systems. The study was conducted over 16 wk and compared conditions in 8 rodent rooms that had ventilation rates of 5 to 6 air changes per hour (ACH) with those in rooms at 10 to 12 ACH. At the low ventilation rate, rooms had higher CO₂ concentrations, higher dew point temperature, and lower particulate levels and spent a greater percentage of time above the temperature set point than did rooms at the high rate. The levels of allergens and endotoxins in room air were the same regardless of the ventilation rate. Differences seen in parameters within cages at the 2 ventilation rates were operationally irrelevant. We detected no total volatile organic compounds in the room that were attributable to ammonia, regardless of the ventilation rate. Clearing the air of ethanol after a spill took longer at the low compared with high rate. However, ethanol clearance was faster at the low rate when the demand-control system was activated than at the high ventilation rate alone. Air quality in the room and in the cages were acceptable with room ventilation rates of 5 to 6 ACH in rodent rooms that use direct-exhaust IVC systems.

  1. Effect of Room Ventilation Rates in Rodent Rooms with Direct-Exhaust IVC Systems

    PubMed Central

    Geertsema, Roger S; Lindsell, Claire E

    2015-01-01

    When IVC are directly exhausted from a rodent housing room, the air quality of the room can become independent of the intracage air quality and may reduce the need for high room ventilation rates. This study assessed the effect of decreasing the ventilation rate in rodent rooms using direct-exhaust IVC systems. The study was conducted over 16 wk and compared conditions in 8 rodent rooms that had ventilation rates of 5 to 6 air changes per hour (ACH) with those in rooms at 10 to 12 ACH. At the low ventilation rate, rooms had higher CO2 concentrations, higher dew point temperature, and lower particulate levels and spent a greater percentage of time above the temperature set point than did rooms at the high rate. The levels of allergens and endotoxins in room air were the same regardless of the ventilation rate. Differences seen in parameters within cages at the 2 ventilation rates were operationally irrelevant. We detected no total volatile organic compounds in the room that were attributable to ammonia, regardless of the ventilation rate. Clearing the air of ethanol after a spill took longer at the low compared with high rate. However, ethanol clearance was faster at the low rate when the demand-control system was activated than at the high ventilation rate alone. Air quality in the room and in the cages were acceptable with room ventilation rates of 5 to 6 ACH in rodent rooms that use direct-exhaust IVC systems. PMID:26424250

  2. Preoperational test report, primary ventilation condenser cooling system

    SciTech Connect

    Clifton, F.T.

    1997-10-29

    This represents the preoperational test report for the Primary Ventilation Condenser Cooling System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system uses a closed chilled water piping loop to provide offgas effluent cooling for tanks AY101, AY102, AZ1O1, AZ102; the offgas is cooled from a nominal 100 F to 40 F. Resulting condensation removes tritiated vapor from the exhaust stack stream. The piping system includes a package outdoor air-cooled water chiller with parallel redundant circulating pumps; the condenser coil is located inside a shielded ventilation equipment cell. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  3. New Control Design Principles Based on Measured Performance and Energy Analysis of HVAC (Heating, Ventilating, and Air-Conditioning) Systems.

    DTIC Science & Technology

    1985-01-01

    economy cycle that does not use PI con- trol. Using PI control for both the cooling coil and the economy cycle pro- duces more than a 20 percent...savings over the same system with proportional- only control. The system using PI control for both the coil and dampers cold- deck reset is the most...Furthermore, the use of PI control instead of proportional-only control has much the same beneficial impact on system energy consumption as using -. cold

  4. Effect of ventilation systems and air filters on decay rates of particles produced by indoor sources in an occupied townhouse

    NASA Astrophysics Data System (ADS)

    Howard-Reed, Cynthia; Wallace, Lance A.; Emmerich, Steven J.

    Several studies have shown the importance of particle losses in real homes due to deposition and filtration; however, none have quantitatively shown the impact of using a central forced air fan and in-duct filter on particle loss rates. In an attempt to provide such data, we measured the deposition of particles ranging from 0.3 to 10 μm in an occupied townhouse and also in an unoccupied test house. Experiments were run with three different sources (cooking with a gas stove, citronella candle, pouring kitty litter), with the central heating and air conditioning (HAC) fan on or off, and with two different types of in-duct filters (electrostatic precipitator and ordinary furnace filter). Particle size, HAC fan operation, and the electrostatic precipitator had significant effects on particle loss rates. The standard furnace filter had no effect. Surprisingly, the type of source (combustion vs. mechanical generation) and the type of furnishings (fully furnished including carpet vs. largely unfurnished including mostly bare floor) also had no measurable effect on the deposition rates of particles of comparable size. With the HAC fan off, average deposition rates varied from 0.3 h -1 for the smallest particle range (0.3-0.5 μm) to 5.2 h -1 for particles greater than 10 μm. Operation of the central HAC fan approximately doubled these rates for particles <5 μm, and increased rates by 2 h -1 for the larger particles. An in-duct electrostatic precipitator increased the loss rates compared to the fan-off condition by factors of 5-10 for particles <2.5 μm, and by a factor of 3 for 2.5-5.0 μm particles. In practical terms, use of the central fan alone could reduce indoor particle concentrations by 25-50%, and use of an in-duct ESP could reduce particle concentrations by 55-85% compared to fan-off conditions.

  5. 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...

  6. Hydrostatic Hyperbaric Chamber Ventilation System

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam M.

    2011-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications, including the treatment of medical conditions. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy available in the developing world for the treatment of a variety of medical conditions. Specifically, hyperbaric oxygen therapy is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. Hyperbaric oxygen therapy is simply too expensive and too dangerous to implement in the developing world using standard equipment. The hydrostatic hyperbaric chamber technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system that will provide controlled pressurization of the system, and provide adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the

  7. Hydrostatic Hyperbaric Chamber Ventilation System

    NASA Technical Reports Server (NTRS)

    Sarguisingh, Miriam J.

    2012-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy (HBOT) available in the developing world for the treatment of a variety of medical conditions. Specifically, HBOT is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. HBOT is simply too expensive and too dangerous to implement in the developing world using standard equipment. The HHC technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system to provide controlled pressurization and adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware

  8. Value impact analysis of Generic Issue 143, Availability of Heating, Ventilation, Air Conditioning (HVAC) and Chilled Water Systems

    SciTech Connect

    Daling, P.M.; Marler, J.E.; Vo, T.V.; Phan, H.; Friley, J.R.

    1993-11-01

    This study evaluates the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143, ``Availability of HVAC and Chilled Water Systems.`` The study identifies vulnerabilities related to failures of HVAC, chilled water, and room cooling systems; develops estimates of room heatup rates and safety-related equipment vulnerabilities following losses of HVAC/room cooler systems; develops estimates of the core damage frequencies and public risks associated with failures of these systems; develops three proposed resolution strategies to this generic issue; and performs a value/impact analysis of the proposed resolutions. Existing probabilistic risk assessments for four representative plants, including one plant from each vendor, form the basis for the core damage frequency and public risk calculations. Both internal and external events were considered. It was concluded that all three proposed resolution strategies exceed the $1,000/person-rem cost-effectiveness ratio. Additional evaluations were performed to develop ``generic`` insights on potential design-related and configuration-related vulnerabilities and potential high-frequency ({approximately}1E-04/RY) accident sequences that involve failures of HVAC/room cooling functions. It was concluded that, although high-frequency accident sequences may exist at some plants, these high-frequency sequences are plant-specific in nature or have been resolved through hardware and/or operational changes. The plant-specific Individual Plant Examinations are an effective vehicle for identification and resolution of these plant-specific anomalies and hardware configurations.

  9. Availability Analysis of the Ventilation Stack CAM Interlock System

    SciTech Connect

    YOUNG, J.

    2000-08-09

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies, and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability.

  10. Evaluating Ventilation Systems for Existing Homes

    SciTech Connect

    Aldrich, Robb; Arena, Lois

    2013-02-01

    In an effort to improve housing options near Las Vegas, Nevada, the Clark County Community Resources Division (CCCRD) performs substantial renovations to foreclosed homes. After dramatic energy, aesthetic, and health and safety improvements are made, homes are rented or sold to qualified residents. This report describes the evaluation and selection of ventilation systems for these homes, including key considerations when selecting an ideal system. The report then describes CCCRD’s decision process with respect to ventilation.

  11. Simplified tools for evaluating domestic ventilation systems

    SciTech Connect

    Maansson, L.G.; Orme, M.

    1999-07-01

    Within an International Energy Agency (IEA) project, Annex 27, experts from 8 countries (Canada, France, Italy, Japan, The Netherlands, Sweden, UK and USA) have developed simplified tools for evaluating domestic ventilation systems during the heating season. Tools for building and user aspects, thermal comfort, noise, energy, life cycle cost, reliability and indoor air quality (IAQ) have been devised. The results can be used both for dwellings at the design stage and after construction. The tools lead to immediate answers and indications about the consequences of different choices that may arise during discussion with clients. This paper presents an introduction to these tools. Examples applications of the indoor air quality and energy simplified tools are also provided. The IAQ tool accounts for constant emission sources, CO{sub 2}, cooking products, tobacco smoke, condensation risks, humidity levels (i.e., for judging the risk for mould and house dust mites), and pressure difference (for identifying the risk for radon or land fill spillage entering the dwelling or problems with indoor combustion appliances). An elaborated set of design parameters were worked out that resulted in about 17,000 combinations. By using multi-variate analysis it was possible to reduce this to 174 combinations for IAQ. In addition, a sensitivity analysis was made using 990 combinations. The results from all the runs were used to develop a simplified tool, as well as quantifying equations relying on the design parameters. A computerized energy tool has also been developed within this project, which takes into account air tightness, climate, window airing pattern, outdoor air flow rate and heat exchange efficiency.

  12. Ventilation, indoor air quality, and health in homes undergoing weatherization.

    PubMed

    Francisco, P W; Jacobs, D E; Targos, L; Dixon, S L; Breysse, J; Rose, W; Cali, S

    2017-03-01

    Ventilation standards, health, and indoor air quality have not been adequately examined for residential weatherization. This randomized trial showed how ASHRAE 62-1989 (n=39 houses) and ASHRAE 62.2-2010 (n=42 houses) influenced ventilation rates, moisture balance, indoor air quality, and self-reported physical and mental health outcomes. Average total airflow was nearly twice as high for ASHRAE 62.2-2010 (79 vs. 39 cfm). Volatile organic compounds, formaldehyde and carbon dioxide were all significantly reduced for the newer standard and first-floor radon was marginally lower, but for the older standard, only formaldehyde significantly decreased. Humidity in the ASHRAE 62.2-2010 group was only about half that of the ASHRAE 62-1989 group using the moisture balance metric. Radon was higher in the basement but lower on the first floor for ASHRAE 62.2-2010. Children in each group had fewer headaches, eczema, and skin allergies after weatherization and adults had improvements in psychological distress. Indoor air quality and health improve when weatherization is accompanied by an ASHRAE residential ventilation standard, and the 2010 ASHRAE standard has greater improvements in certain outcomes compared to the 1989 standard. Weatherization, home repair, and energy conservation projects should use the newer ASHRAE standard to improve indoor air quality and health.

  13. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Mechanical ventilation system: Standards. 154.1205... Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts...

  14. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Mechanical ventilation system: Standards. 154.1205... Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts...

  15. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Mechanical ventilation system: General. 154.1200 Section... Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a... cargo handling equipment must have a fixed, exhaust-type mechanical ventilation system. (b)...

  16. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Mechanical ventilation system: General. 154.1200 Section... Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a... cargo handling equipment must have a fixed, exhaust-type mechanical ventilation system. (b)...

  17. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Mechanical ventilation system: Standards. 154.1205... Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts...

  18. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Mechanical ventilation system: Standards. 154.1205... Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts...

  19. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Mechanical ventilation system: General. 154.1200 Section... Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a... cargo handling equipment must have a fixed, exhaust-type mechanical ventilation system. (b)...

  20. Co-occupant's exposure to exhaled pollutants with two types of personalized ventilation strategies under mixing and displacement ventilation systems.

    PubMed

    Li, X; Niu, J; Gao, N

    2013-04-01

    Personalized ventilation (PV) system in conjunction with total ventilation system can provide cleaner inhaled air for the user. Concerns still exist about whether the normally protecting PV device, on the other hand, facilitates the dispersion of infectious agents generated by its user. In this article, two types of PV systems with upward supplied fresh air, namely a chair-based PV and one kind of desk-mounted PV systems, when combined with mixing ventilation (MV) and displacement ventilation (DV) systems, are investigated using simulation method with regard to their impacts on co-occupant's exposure to the exhaled droplet nuclei generated by the infected PV user. Simulation results of tracer gas and particles with aerodynamic diameter of 1, 5, and 10 μm from exhaled air show that, when only the infected person uses a PV, the different PV air supplying directions present very different impacts on the co-occupant's intake under DV, while no apparent differences can be observed under MV. The findings demonstrate that better inhaled air quality can always be achieved under DV when the adopted PV system can deliver conditioned fresh air in the same direction with the mainly upward airflow patterns of DV.

  1. Argonne Fuel Cycle Facility ventilation system -- modeling and results

    SciTech Connect

    Mohr, D.; Feldman, E.E.; Danielson, W.F.

    1995-02-01

    This paper describes an integrated study of the Argonne-West Fuel Cycle Facility (FCF) interconnected ventilation systems during various operations. Analyses and test results include first a nominal condition reflecting balanced pressures and flows followed by several infrequent and off-normal scenarios. This effort is the first study of the FCF ventilation systems as an integrated network wherein the hydraulic effects of all major air systems have been analyzed and tested. The FCF building consists of many interconnected regions in which nuclear fuel is handled, transported and reprocessed. The ventilation systems comprise a large number of ducts, fans, dampers, and filters which together must provide clean, properly conditioned air to the worker occupied spaces of the facility while preventing the spread of airborne radioactive materials to clean am-as or the atmosphere. This objective is achieved by keeping the FCF building at a partial vacuum in which the contaminated areas are kept at lower pressures than the other worker occupied spaces. The ventilation systems of FCF and the EBR-II reactor are analyzed as an integrated totality, as demonstrated. We then developed the network model shown in Fig. 2 for the TORAC code. The scope of this study was to assess the measured results from the acceptance/flow balancing testing and to predict the effects of power failures, hatch and door openings, single-failure faulted conditions, EBR-II isolation, and other infrequent operations. The studies show that the FCF ventilation systems am very controllable and remain stable following off-normal events. In addition, the FCF ventilation system complex is essentially immune to reverse flows and spread of contamination to clean areas during normal and off-normal operation.

  2. 30 CFR 75.350 - Belt air course ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Belt air course ventilation. 75.350 Section 75... (ii), effective Aug. 1, 2014. For the convenience of the user, the revised text is set forth as...: (A) 1.0 mg/m3. (B) 0.5 mg/m3 as of August 1, 2016. (ii) Where miners on the working section are on...

  3. Three years of experience with a dissection table ventilation system.

    PubMed

    Martin, W D; Nemitz, J W; Hendley, A; Fisk, R M; Wells, J P

    1995-01-01

    A dissection table ventilation system that draws air across the cadaver and away from the table top was designed to fit the Shandon-Lipshaw AN-52 dissection table. Each U-shaped unit consists of a pair of hollow collection arms that attach to a collecting manifold at one end. During dissection the manifold is coupled to a central ventilation system through a flexible duct. The air from the table ventilation system is exhausted after passing through a heat recovery system. The unit is raised from the table surface during dissection of the body cavities to increase the efficiency of fume/odor removal. Eight hour exposure data for formaldehyde concentrations are presented. Data were collected from detectors positioned at selected levels above the cadaver during dissection, and above a tray on the table top containing a known volume of 4% formaldehyde or the West Virginia School of Osteopathic Medicine embalming fluid under varying airflow conditions. The results demonstrate that the table ventilation system is effective in reducing exposure to formaldehyde in the dissection laboratory.

  4. Multifamily Individual Heating and Ventilation Systems, Lawrence, Massachusetts (Fact Sheet)

    SciTech Connect

    Not Available

    2013-11-01

    The conversion of an older Massachusetts building into condominiums illustrates a safe, durable, and cost-effective solution for heating and ventilation systems that can potentially benefit millions of multifamily buildings. Merrimack Valley Habitat for Humanity (MVHfH) partnered with U.S. Department of Energy Building America team Building Science Corporation (BSC) to provide high performance affordable housing for 10 families in the retrofit of an existing mass masonry building (a former convent). The original ventilation design for the project was provided by a local engineer and consisted of a single large heat recovery ventilator (HRV) located in a mechanical room in the basement with a centralized duct system providing supply air to the main living space and exhausting stale air from the single bathroom in each apartment. This design was deemed to be far too costly to install and operate for several reasons: the large central HRV was oversized and the specified flows to each apartment were much higher than the ASHRAE 62.2 rate; an extensive system of ductwork, smoke and fire dampers, and duct chases were specified; ductwork required a significant area of dropped ceilings; and the system lacked individual ventilation control in the apartments

  5. CAN SORBENT-BASED GAS PHASE AIR CLEANING FOR VOCS SUBSTITUTE FOR VENTILATION IN COMMERCIAL BUILDINGS?

    SciTech Connect

    Fisk, William; Fisk, William J.

    2007-08-01

    This paper reviews current knowledge about the suitability of sorbent-based air cleaning for removing volatile organic compounds (VOCs) from the air in commercial buildings, as needed to enable reductions in ventilation rates and associated energy savings. The principles of sorbent air cleaning are introduced, criteria are suggested for sorbent systems that can counteract indoor VOC concentration increases from reduced ventilation, major findings from research on sorbent performance for this application are summarized, and related priority research needs are identified. Major conclusions include: sorbent systems can remove a broad range of VOCs with moderate to high efficiency, sorbent technologies perform effectively when challenged with VOCs at the low concentrations present indoors, and there is a large uncertainty about the lifetime and associated costs of sorbent air cleaning systems when used in commercial buildings for indoor VOC control. Suggested priority research includes: experiments to determine sorbent system VOC removal efficiencies and lifetimes considering the broad range and low concentration of VOCs indoors; evaluations of in-situ regeneration of sorbents; and an updated analysis of the cost of sorbent air cleaning relative to the cost of ventilation.

  6. Heating, ventilation and air conditioning system optimization: a study of the effect of climate, building design, system selection and control strategy on the energy consumption of a typical office building in London and Athens

    NASA Astrophysics Data System (ADS)

    Spasis, Georgios

    The increasing demand for air conditioning in commercial buildings imposes a serious threat to Europe's CO2 reduction targets. Architects and engineers are therefore in a key position to help reduce the impact of buildings on the environment by taking appropriate decisions concerning the design of the building and the associated heating, ventilation and air conditioning (HVAC) system. The thesis studies the effect of a number of building and HVAC system related design factors on the energy performance of a notional air-conditioned office building employing either a variable air volume (VAV) system with terminal re-heaters, or a four-pipe fan coil unit (FCU) system with fresh air supply from a central plant, using mainly a dynamic simulation tool and the response surface methodology. The evaluation of the energy performance of the HVAC systems is for two types of climate, using typical weather data for London (UK) and Athens (Greece). It has been found that the design variables associated with the solar radiation through the transparent building elements and the internal heat gains should be the main concern of the building designer. On the other hand, the HVAC system engineer should give emphasis to the parameters associated with the plant performance and operation, as well as the temperature control set-points. It has been shown that it is possible to reduce the carbon emissions of the base case scenario by up to 88% depending on the HVAC system and the climate for which it is simulated. The carbon savings, however, are reduced by up to 22% where humidification is provided. This reduction differs depending on the HVAC system and the climatic conditions. The VAV system is more energy efficient than the FCU system, mainly due to the exploitation of the free cooling capacity of the outdoor air. The difference in carbon emissions between the two systems drops when both of them are simulated for the Athens as opposed to the London typical weather conditions. It has

  7. 21 CFR 211.46 - Ventilation, air filtration, air heating and cooling.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Ventilation, air filtration, air heating and cooling. 211.46 Section 211.46 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED...

  8. Optimization of Ventilation Energy Demands and Indoor Air Quality in High-Performance Homes

    SciTech Connect

    Hun, Diana E; Jackson, Mark C; Shrestha, Som S

    2014-01-01

    High-performance homes require that ventilation energy demands and indoor air quality (IAQ) be simultaneously optimized. We attempted to bridge these two areas by conducting tests in a research house located in Oak Ridge, TN, that was 20 months old, energy-efficient (i.e., expected to consume 50% less energy than a house built per the 2006 IRC), tightly-built (i.e., natural ventilation rate ~0.02 h-1), unoccupied, and unfurnished. We identified air pollutants of concern in the test home that could generally serve as indicators of IAQ, and conduced field experiments and computer simulations to determine the effectiveness and energy required by various techniques that lessened the concentration of these contaminants. Formaldehyde was selected as the main pollutant of concern among the contaminants that were sampled in the initial survey because it was the only compound that showed concentrations that were greater than the recommended exposure levels. Field data indicate that concentrations were higher during the summer primarily because emissions from sources rise with increases in temperature. Furthermore, supply ventilation and gas-phase filtration were effective means to reduce formaldehyde concentrations; however, exhaust ventilation had minimal influence on this pollutant. Results from simulations suggest that formaldehyde concentrations obtained while ventilating per ASHRAE 62.2-2010 could be decreased by about 20% from May through September through three strategies: 1) increasing ASHRAE supply ventilation by a factor of two, 2) reducing the thermostat setpoint from 76 to 74 F, or 3) running a gas-phase filtration system while decreasing supply ventilation per ASHRAE by half. In the mixed-humid climate of Oak Ridge, these strategies caused increases in electricity cost of ~$5 to ~$15/month depending on outdoor conditions.

  9. Radioactive waste tank ventilation system incorporating tritium control

    SciTech Connect

    Rice, P.D.

    1997-08-01

    This paper describes the development of a ventilation system for radioactive waste tanks at the U.S. Department of Energy`s (DOE) Hanford Site in Richland, Washington. The unique design of the system is aimed at cost-effective control of tritiated water vapor. The system includes recirculation ventilation and cooling for each tank in the facility and a central exhaust air clean-up train that includes a low-temperature vapor condenser and high-efficiency mist eliminator (HEME). A one-seventh scale pilot plant was built and tested to verify predicted performance of the low-temperature tritium removal system. Tests were conducted to determine the effectiveness of the removal of condensable vapor and soluble and insoluble aerosols and to estimate the operating life of the mist eliminator. Definitive design of the ventilation system relied heavily on the test data. The unique design features of the ventilation system will result in far less release of tritium to the atmosphere than from conventional high-volume dilution systems and will greatly reduce operating costs. NESHAPs and TAPs NOC applications have been approved, and field construction is nearly complete. Start-up is scheduled for late 1996. 3 refs., 4 figs., 2 tabs.

  10. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts for... duct under paragraph (a) of this section must be at least 10 m (32.8 ft.) from ventilation intakes and... operational controls outside the ventilated space. (g) No ventilation duct for a gas-dangerous space may...

  11. Optimization of Ventilation Energy Demands and Indoor Air Quality in the ZEBRAlliance Homes

    SciTech Connect

    Hun, D.; Jackson, M.; Shrestha, S.

    2013-09-01

    High-performance homes require that ventilation energy demands and indoor air quality (IAQ) be simultaneously optimized. In this project, Oak Ridge National Laboratory researchers attempted to bridge these two areas by conducting tests in research houses located in Oak Ridge, TN, that were less than 2 years old, energy-efficient (i.e., expected to consume 50% less energy than a house built per the 2006 IRC), tightly-built, unoccupied, and unfurnished. The team identified air pollutants of concern in the test homes that could generally serve as indicators of IAQ, and conduced field experiments and computer simulations to determine the effectiveness and energy required by various techniques that lessened the concentration of these contaminants. Formaldehyde was selected as the main pollutant of concern from initial air sampling surveys. Field data indicate that concentrations were higher during the summer primarily because emissions from sources rise with increases in temperature. Furthermore, supply ventilation and gas-phase filtration were effective means to reduce formaldehyde concentrations; however, exhaust ventilation had minimal influence on this pollutant. Results from simulations suggest that formaldehyde concentrations obtained while ventilating per ASHRAE 62.2-2010 could be decreased by about 20% from May through September through three strategies: 1) increasing ASHRAE supply ventilation by a factor of two, 2) reducing the thermostat setpoint from 76 to 74°F, or 3) running a gas-phase filtration system while decreasing supply ventilation per ASHRAE by half. In the mixed-humid climate of Oak Ridge, these strategies caused minimal to modest increases in electricity cost of ~$5 to ~$15/month depending on outdoor conditions.

  12. Project Design Concept Primary Ventilation System

    SciTech Connect

    MCGREW, D.L.

    2000-10-02

    Tank Farm Restoration and Safe Operation (TFRSO), Project W-3 14 was established to provide upgrades that would improve the reliability and extend the system life of portions of the waste transfer, electrical, ventilation, instrumentation and control systems for the Hanford Site Tank Farms. An assessment of the tank farm system was conducted and the results are documented in system assessment reports. Based on the deficiencies identified in the tank farm system assessment reports, and additional requirements analysis performed in support of the River Protection Project (RPP), an approved scope for the TFRSO effort was developed and documented in the Upgrade Scope Summary Report (USSR), WHC-SD-W314-RPT-003, Rev. 4. The USSR establishes the need for the upgrades and identifies the specific equipment to be addressed by this project. This Project Design Concept (PDC) is in support of the Phase 2 upgrades and provides an overall description of the operations concept for the W-314 Primary Ventilation Systems. Actual specifications, test requirements, and procedures are not included in this PDC. The PDC is a ''living'' document, which will be updated throughout the design development process to provide a progressively more detailed description of the W-314 Primary Ventilation Systems design. The Phase 2 upgrades to the Primary Ventilation Systems shall ensure that the applicable current requirements are met for: Regulatory Compliance; Safety; Mission Requirements; Reliability; and Operational Requirements.

  13. Indoor Chemistry: Materials, Ventilation Systems, and Occupant Activities

    SciTech Connect

    Morrison, G.C.; Corsi, R.L.; Destaillats, H.; Nazaroff, W.W.; Wells, J.R.

    2006-05-01

    Chemical processes taking place in indoor environments can significantly alter the nature and concentrations of pollutants. Exposure to secondary contaminants generated in these reactions needs to be evaluated in association with many aspects of buildings to minimize their impact on occupant health and well-being. Focusing on indoor ozone chemistry, we describe alternatives for improving indoor air quality by controlling chemical changes related to building materials, ventilation systems, and occupant activities.

  14. MODELING VENTILATION SYSTEM RESPONSE TO FIRE

    SciTech Connect

    Coutts, D

    2007-04-17

    Fires in facilities containing nuclear material have the potential to transport radioactive contamination throughout buildings and may lead to widespread downwind dispersal threatening both worker and public safety. Development and implementation of control strategies capable of providing adequate protection from fire requires realistic characterization of ventilation system response which, in turn, depends on an understanding of fire development timing and suppression system response. This paper discusses work in which published HEPA filter data was combined with CFAST fire modeling predictions to evaluate protective control strategies for a hypothetical DOE non-reactor nuclear facility. The purpose of this effort was to evaluate when safety significant active ventilation coupled with safety class passive ventilation might be a viable control strategy.

  15. Effects of air ventilation during stationary exercise testing.

    PubMed

    Van Schuylenbergh, R; Vanden Eynde, B; Hespel, P

    2004-07-01

    The impact of air ventilation on performance and physiological responses during stationary exercise in the laboratory was studied. Fourteen well-trained cyclists performed three exercise tests on a cycle ergometer, each separated by a 1-week interval. The first test was a graded test to determine the power output corresponding with the 4-mmol l(-1) lactate level. Tests 2 and 3 were 30-min constant-load tests at a power output corresponding with this 4-mmol l(-1) lactate threshold. One constant-load test was performed in the absence (NAV), whilst the other was performed in the presence (AV) of air ventilation (3 m s(-1)). During the constant-load tests, heart rate, tympanic temperature, blood lactate concentration and oxygen uptake (VO2) were measured at 10-min intervals and at the end of the test. Differences between the two test conditions were evaluated using paired t-tests. During NAV, 12 subjects interrupted the test due to premature exhaustion (exercise duration <30 min), versus only seven in AV ( P<0.05). At the end of the test tympanic temperature was 35.9 (0.2) degrees C in AV and was higher in NAV [36.7 (0.2) degrees C, P<0.05]. Exercise heart rate increased at a faster rate during NAV [+2.2 (0.3) beats min(-1)] than during AV [+1.5 (0.2) beats min(-1), P<0.05]. Blood lactate concentration and VO2 were similar between conditions. Air ventilation is essential to prevent an upward shift in the lactate:heart rate as well as the power output:heart rate relationship during laboratory exercise testing and indoor exercise training.

  16. Impact of heating and air conditioning system operation and leakage on ventilation and intercompartment transport: studies in unoccupied and occupied Tennessee Valley homes.

    PubMed

    Matthews, T G; Wilson, D L; Thompson, C V; Monar, K P; Dudney, C S

    1990-02-01

    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 0.33 +/- 0.37 h-1 corresponded to an incremental air leak of 240 m3/h, based on approximate house volume. More detailed tracer gas decay studies were performed in basement, kitchen and bedroom locations of six homes with low air infiltration rates (i.e., less than 0.25 h-1). The HAC mixed the indoor air efficiently between measurement sites. HAC operation also caused 1.1- to 3.6-fold increases in air infiltration rates, corresponding to absolute increases of 0.02 to 0.1 h-1. In an unoccupied research house, three-fold increases in average air infiltration rate with HAC operation (i.e., from 0.13 to 0.36 h-1) were reduced to two-fold (i.e., from 0.10 to 0.18 h-1) by sealing the external HAC unit and crawlspace ductwork system. This sealing also resulted in a 30 percent reduction in crawlspace-to-indoor transport rates with the HAC turned on. Blower door tests indicated a less than 20 percent reduction in house leakage area.

  17. Association of ventilation system type with SBS symptoms in office workers

    SciTech Connect

    Seppanen, Olli; Fisk, William J.

    2001-02-07

    This paper provides a review and synthesis of current knowledge about the associations of ventilation system types in office buildings with sick building syndrome symptoms and discusses potential explanations for the associations. Relative to natural ventilation, air conditioning, with or without humidification, was consistently associated with a statistically significant increase in the prevalence of one or more SBS symptoms. Prevalences were typically higher by approximately 30% to 200% in the air conditioned buildings. In two of three assessments from a single study, symptom prevalences were also significantly higher in air conditioned buildings than in buildings with simple mechanical ventilation and no humidification. In approximately half of assessments, SBS symptom prevalences were significantly higher in buildings with simple mechanical ventilation than in buildings with natural ventilation. Insufficient information was available for conclusions about the potential increased risk of SBS symptoms with humidification. The statistically significant associations of mechanical ventilation and air conditioning with SBS symptoms are much more frequent than expected from chance and also not likely to be a consequence of confounding by several potential personal, job, or building related confounders. The reasons for the increases in symptom prevalences with mechanical ventilation and particularly with air conditioning remain unclear. Multiple deficiencies in HVAC system design, construction, operation, or maintenance, including some which cause pollutant emissions from HVAC systems, may contribute to the increases in symptom prevalences.

  18. A numerical method to determine the steady state distribution of passive contaminant in generic ventilation systems.

    PubMed

    Li, Xianting; Shao, Xiaoliang; Ma, Xiaojun; Zhang, Yuanhui; Cai, Hao

    2011-08-15

    Ventilation system with air recirculation is designed to conserve energy, yet at the same time may result in transporting hazardous substance among different rooms in the same building, which is a concern in indoor air quality control. There is a lack of effective methods to predict indoor contaminant distribution primarily because of uncertainty of the contaminant concentration in supply air which in turn due to the mixing ratio of fresh and recirculation air. In this paper, a versatile numerical method to determine the pollutant distribution of ventilation system with recirculation at steady state is proposed based on typical ventilation systems with accessibility of supply air (ASA) and accessibility of contaminant source (ACS). The relationship is established between contaminant concentrations of supply air and return air in a ventilated room or zone. The concentrations of supply air and contaminant distribution in each room can be determined using such parameters as ASA and ACS. The proposed method is validated by both experimental data and numerical simulation result. The computing speed of the proposed method is compared with the iteration method. The comparisons between the proposed method and the lumped parameter model are also conducted. The advantages of the proposed method in terms of accuracy, speed and versatility make it advantageous to be applied in air quality control of complex ventilation systems with recirculation.

  19. Exhaust ventilation in attached garages improves residential indoor air quality.

    PubMed

    Mallach, G; St-Jean, M; MacNeill, M; Aubin, D; Wallace, L; Shin, T; Van Ryswyk, K; Kulka, R; You, H; Fugler, D; Lavigne, E; Wheeler, A J

    2017-03-01

    Previous research has shown that indoor benzene levels in homes with attached garages are higher than homes without attached garages. Exhaust ventilation in attached garages is one possible intervention to reduce these concentrations. To evaluate the effectiveness of this intervention, a randomized crossover study was conducted in 33 Ottawa homes in winter 2014. VOCs including benzene, toluene, ethylbenzene, and xylenes, nitrogen dioxide, carbon monoxide, and air exchange rates were measured over four 48-hour periods when a garage exhaust fan was turned on or off. A blower door test conducted in each garage was used to determine the required exhaust fan flow rate to provide a depressurization of 5 Pa in each garage relative to the home. When corrected for ambient concentrations, the fan decreased geometric mean indoor benzene concentrations from 1.04 to 0.40 μg/m(3) , or by 62% (P<.05). The garage exhaust fan also significantly reduced outdoor-corrected geometric mean indoor concentrations of other pollutants, including toluene (53%), ethylbenzene (47%), m,p-xylene (45%), o-xylene (43%), and carbon monoxide (23%) (P<.05) while having no impact on the home air exchange rate. This study provides evidence that mechanical exhaust ventilation in attached garages can reduce indoor concentrations of pollutants originating from within attached garages.

  20. Building America Case Study: Selecting Ventilation Systems for Existing Homes (Fact Sheet)

    SciTech Connect

    Not Available

    2014-12-01

    This document addresses adding -or improving - mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards. Advantages, disadvantages, and approximate costs of various system types are presented along with general guidelines for implementing the systems in homes. CARB intends for this document to be useful to decision makers and contractors implementing ventilation systems in homes. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors. It is the intent of this document to assist contractors in making more informed decisions when selecting systems. Ventilation is an integral part of a high-performance home. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability.

  1. A ventilation intervention study in classrooms to improve indoor air quality: the FRESH study

    PubMed Central

    2013-01-01

    Background Classroom ventilation rates often do not meet building standards, although it is considered to be important to improve indoor air quality. Poor indoor air quality is thought to influence both children’s health and performance. Poor ventilation in The Netherlands most often occurs in the heating season. To improve classroom ventilation a tailor made mechanical ventilation device was developed to improve outdoor air supply. This paper studies the effect of this intervention. Methods The FRESH study (Forced-ventilation Related Environmental School Health) was designed to investigate the effect of a CO2 controlled mechanical ventilation intervention on classroom CO2 levels using a longitudinal cross-over design. Target CO2 concentrations were 800 and 1200 parts per million (ppm), respectively. The study included 18 classrooms from 17 schools from the north-eastern part of The Netherlands, 12 experimental classrooms and 6 control classrooms. Data on indoor levels of CO2, temperature and relative humidity were collected during three consecutive weeks per school during the heating seasons of 2010–2012. Associations between the intervention and weekly average indoor CO2 levels, classroom temperature and relative humidity were assessed by means of mixed models with random school-effects. Results At baseline, mean CO2 concentration for all schools was 1335 ppm (range: 763–2000 ppm). The intervention was able to significantly decrease CO2 levels in the intervention classrooms (F (2,10) = 17.59, p < 0.001), with a mean decrease of 491 ppm. With the target set at 800 ppm, mean CO2 was 841 ppm (range: 743–925 ppm); with the target set at 1200 ppm, mean CO2 was 975 ppm (range: 887–1077 ppm). Conclusions Although the device was not capable of precisely achieving the two predefined levels of CO2, our study showed that classroom CO2 levels can be reduced by intervening on classroom ventilation using a CO2 controlled mechanical ventilation system

  2. Development of an air-bearing fan for space extravehicular activity (EVA) suit ventilation

    NASA Technical Reports Server (NTRS)

    Fukumoto, Paul; Allen, Norman; Stonesifer, Greg

    1992-01-01

    A high-speed/variable flow fan has been developed for EVA suit ventilation which combines air bearings with a two-pole, toothless permanent-magnet motor. The fan has demonstrated quiet and vibration-free operation and a 2:1 range in flow rate variation. System weight is 0.9 kg, and input powers range from 12.4 to 42 W.

  3. Evaluation of an Incremental Ventilation Energy Model for Estimating Impacts of Air Sealing and Mechanical Ventilation

    SciTech Connect

    Logue, Jennifer M.; Turner, Willliam JN; Walker, Iain S.; Singer, Brett C.

    2012-07-01

    Changing the rate of airflow through a home affects the annual thermal conditioning energy. Large-scale changes to airflow rates of the housing stock can significantly alter the energy consumption of the residential energy sector. However, the complexity of existing residential energy models hampers the ability to estimate the impact of policy changes on a state or nationwide level. The Incremental Ventilation Energy (IVE) model developed in this study was designed to combine the output of simple airflow models and a limited set of home characteristics to estimate the associated change in energy demand of homes. The IVE model was designed specifically to enable modelers to use existing databases of home characteristics to determine the impact of policy on ventilation at a population scale. In this report, we describe the IVE model and demonstrate that its estimates of energy change are comparable to the estimates of a wellvalidated, complex residential energy model when applied to homes with limited parameterization. Homes with extensive parameterization would be more accurately characterized by complex residential energy models. The demonstration included a range of home types, climates, and ventilation systems that cover a large fraction of the residential housing sector.

  4. Effects of energy-efficient ventilation rates on indoor air quality at an Ohio elementary school

    NASA Astrophysics Data System (ADS)

    Berk, J. V.; Young, R.; Hollowell, C. D.; Turiel, I.; Pepper, J.

    1980-04-01

    A mobile laboratory was used to monitor air outdoors and at three indoor sites (two classrooms and a large multipurpose room); tests were made at three different ventilation rates. The parameters measured were outside air flow rates, odor perception, microbial burden, particulate mass, total aldehydes, carbon dioxide, ozone, and nitrogen oxides. The results of these measurements are given and compared with the existing outdoor air quality standards. Carbon dioxide concentrations increased as the ventilation rate decreased, but still did not exceed current standards. Odor perceptibility increased slightly at the lowest ventilation rate. Other pollutants showed very low concentrations, which did not change with reductions in ventilation rate.

  5. An air bearing fan for EVA suit ventilation

    NASA Technical Reports Server (NTRS)

    Murry, Roger P.

    1990-01-01

    The portable life-support system (PLSS) ventilation requirements are outlined, along with the application of a high-speed axial fan technology for extravehicular-activity (EVA) space-suit ventilation. Focus is placed on a mechanical design employing high-speed gas bearings, permanent magnet rotor, and current-fed chopper/inverter electronics. The operational characteristics of the fan unit and its applicability for use in a pure-oxygen environment are discussed. It delivers a nominal 0.17 cu m/min at 1.24 kPa pressure rise using 13.8 w of input power. It is shown that the overall selection of materials for all major component meets the NASA requirements.

  6. 46 CFR 153.310 - Ventilation system type.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Ventilation system type. 153.310 Section 153.310... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Handling Space Ventilation § 153.310 Ventilation system type. A cargo handling space must have a...

  7. 46 CFR 153.312 - Ventilation system standards.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Ventilation system standards. 153.312 Section 153.312... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Handling Space Ventilation § 153.312 Ventilation system standards. A cargo handling space...

  8. 46 CFR 153.312 - Ventilation system standards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ventilation system standards. 153.312 Section 153.312... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Handling Space Ventilation § 153.312 Ventilation system standards. A cargo handling space...

  9. 46 CFR 153.310 - Ventilation system type.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Ventilation system type. 153.310 Section 153.310... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Handling Space Ventilation § 153.310 Ventilation system type. A cargo handling space must have a...

  10. 46 CFR 153.310 - Ventilation system type.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Ventilation system type. 153.310 Section 153.310... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Handling Space Ventilation § 153.310 Ventilation system type. A cargo handling space must have a...

  11. 46 CFR 153.310 - Ventilation system type.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ventilation system type. 153.310 Section 153.310... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Handling Space Ventilation § 153.310 Ventilation system type. A cargo handling space must have a...

  12. 46 CFR 153.310 - Ventilation system type.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ventilation system type. 153.310 Section 153.310... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Handling Space Ventilation § 153.310 Ventilation system type. A cargo handling space must have a...

  13. 46 CFR 153.312 - Ventilation system standards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Ventilation system standards. 153.312 Section 153.312... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Handling Space Ventilation § 153.312 Ventilation system standards. A cargo handling space...

  14. 46 CFR 153.312 - Ventilation system standards.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Ventilation system standards. 153.312 Section 153.312... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Handling Space Ventilation § 153.312 Ventilation system standards. A cargo handling space...

  15. 33 CFR 183.610 - Powered ventilation system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Powered ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.610 Powered ventilation system. (a) Each compartment in a boat that has a permanently installed gasoline engine with a cranking...

  16. 33 CFR 183.610 - Powered ventilation system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Powered ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.610 Powered ventilation system. (a) Each compartment in a boat that has a permanently installed gasoline engine with a cranking...

  17. 33 CFR 183.610 - Powered ventilation system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Powered ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.610 Powered ventilation system. (a) Each compartment in a boat that has a permanently installed gasoline engine with a cranking...

  18. 33 CFR 183.610 - Powered ventilation system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Powered ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.610 Powered ventilation system. (a) Each compartment in a boat that has a permanently installed gasoline engine with a cranking...

  19. Field Test of Room-to-Room Uniformity of Ventilation Air Distribution in Two New Houses

    SciTech Connect

    Hendron, Robert; Anderson, Ren; Barley, Dennis; Rudd, Armin; Townsend, Aaron; Hancock, Ed

    2006-12-01

    This report describes a field test to characterize the uniformity of room-to-room ventilation air distribution under various operating conditions by examining multi-zone tracer gas decay curves and calculating local age-of-air.

  20. Modeled Effectiveness of Ventilation with Contaminant Control Devices on Indoor Air Quality in a Swine Farrowing Facility

    PubMed Central

    Anthony, T. Renée; Altmaier, Ralph; Park, Jae Hong; Peters, Thomas M.

    2016-01-01

    Because adverse health effects experienced by swine farm workers in concentrated animal feeding operations (CAFOs) have been associated with exposure to dust and gases, efforts to reduce exposures are warranted, particularly in winter seasons when exposures increase due to decreased ventilation. Simulation of air quality and operating costs for ventilating swine CAFO, including treating and recirculating air through a farrowing room, was performed using mass and energy balance equations over a 90-day winter season. System operation required controlling heater operation to achieve room temperatures optimal to ensure animal health (20 to 22.5°C). Five air pollution control devices, four room ventilation rates, and five recirculation patterns were examined. Inhalable dust concentrations were easily reduced using standard industrial air pollution control devices, including a cyclone, filtration, and electrostatic precipitator. Operating ventilation systems at 0.94 m3 s−1 (2000 cfm) with 75 to 100% recirculation of treated air from cyclone, electrostatic precipitator, and shaker dust filtration system achieves adequate particle control with operating costs under $1.00 per pig produced ($0.22 to 0.54), although carbon dioxide (CO2) concentrations approach 2000 ppm using in-room ventilated gas fired heaters. In no simulation were CO2 concentrations below industry recommended concentrations (1540 ppm), but alternative heating devices could reduce CO2 to acceptable concentrations. While this investigation does not represent all production swine farrowing barns, which differ in characteristics including room dimensions and swine occupancy, the simulation model and ventilation optimization methods can be applied to other production sites. This work shows that ventilation may be a cost-effective control option in the swine industry to reduce exposures. PMID:24433305

  1. Modeled effectiveness of ventilation with contaminant control devices on indoor air quality in a swine farrowing facility.

    PubMed

    Anthony, T Renée; Altmaier, Ralph; Park, Jae Hong; Peters, Thomas M

    2014-01-01

    Because adverse health effects experienced by swine farm workers in concentrated animal feeding operations (CAFOs) have been associated with exposure to dust and gases, efforts to reduce exposures are warranted, particularly in winter seasons when exposures increase due to decreased ventilation. Simulation of air quality and operating costs for ventilating swine CAFO, including treating and recirculating air through a farrowing room, was performed using mass and energy balance equations over a 90-day winter season. System operation required controlling heater operation to achieve room temperatures optimal to ensure animal health (20 to 22.5 °C). Five air pollution control devices, four room ventilation rates, and five recirculation patterns were examined. Inhalable dust concentrations were easily reduced using standard industrial air pollution control devices, including a cyclone, filtration, and electrostatic precipitator. Operating ventilation systems at 0.94 m3 s(-1) (2000 cfm) with 75 to 100% recirculation of treated air from cyclone, electrostatic precipitator, and shaker dust filtration system achieves adequate particle control with operating costs under $1.00 per pig produced ($0.22 to 0.54), although carbon dioxide (CO2) concentrations approach 2000 ppm using in-room ventilated gas fired heaters. In no simulation were CO2 concentrations below industry recommended concentrations (1540 ppm), but alternative heating devices could reduce CO2 to acceptable concentrations. While this investigation does not represent all production swine farrowing barns, which differ in characteristics including room dimensions and swine occupancy, the simulation model and ventilation optimization methods can be applied to other production sites. This work shows that ventilation may be a cost-effective control option in the swine industry to reduce exposures.

  2. Thermal comfort in naturally ventilated and air-conditioned buildings in humid subtropical climate zone in China.

    PubMed

    Yang, Wei; Zhang, Guoqiang

    2008-05-01

    A thermal comfort field study has been carried out in five cities in the humid subtropical climate zone in China. The survey was performed in naturally ventilated and air-conditioned buildings during the summer season in 2006. There were 229 occupants from 111 buildings who participated in this study and 229 questionnaire responses were collected. Thermal acceptability assessment reveals that the indoor environment in naturally ventilated buildings could not meet the 80% acceptability criteria prescribed by ASHRAE Standard 55, and people tended to feel more comfortable in air-conditioned buildings with the air-conditioned occupants voting with higher acceptability (89%) than the naturally ventilated occupants (58%). The neutral temperatures in naturally ventilated and air-conditioned buildings were 28.3 degrees C and 27.7 degrees C, respectively. The range of accepted temperature in naturally ventilated buildings (25.0-31.6 degrees C) was wider than that in air-conditioned buildings (25.1-30.3 degrees C), which suggests that occupants in naturally ventilated buildings seemed to be more tolerant of higher temperatures. Preferred temperatures were 27.9 degrees C and 27.3 degrees C in naturally ventilated and air-conditioned buildings, respectively, both of which were 0.4 degrees C cooler than neutral temperatures. This result suggests that people of hot climates may use words like "slightly cool" to describe their preferred thermal state. The relationship between draught sensation and indoor air velocity at different temperature ranges indicates that indoor air velocity had a significant influence over the occupants' comfort sensation, and air velocities required by occupants increased with the increasing of operative temperatures. Thus, an effective way of natural ventilation which can create the preferred higher air movement is called for. Finally, the indoor set-point temperature of 26 degrees C or even higher in air-conditioned buildings was confirmed as making

  3. Thermal comfort in naturally ventilated and air-conditioned buildings in humid subtropical climate zone in China

    NASA Astrophysics Data System (ADS)

    Yang, Wei; Zhang, Guoqiang

    2008-05-01

    A thermal comfort field study has been carried out in five cities in the humid subtropical climate zone in China. The survey was performed in naturally ventilated and air-conditioned buildings during the summer season in 2006. There were 229 occupants from 111 buildings who participated in this study and 229 questionnaire responses were collected. Thermal acceptability assessment reveals that the indoor environment in naturally ventilated buildings could not meet the 80% acceptability criteria prescribed by ASHRAE Standard 55, and people tended to feel more comfortable in air-conditioned buildings with the air-conditioned occupants voting with higher acceptability (89%) than the naturally ventilated occupants (58%). The neutral temperatures in naturally ventilated and air-conditioned buildings were 28.3°C and 27.7°C, respectively. The range of accepted temperature in naturally ventilated buildings (25.0˜31.6°C) was wider than that in air-conditioned buildings (25.1˜30.3°C), which suggests that occupants in naturally ventilated buildings seemed to be more tolerant of higher temperatures. Preferred temperatures were 27.9°C and 27.3°C in naturally ventilated and air-conditioned buildings, respectively, both of which were 0.4°C cooler than neutral temperatures. This result suggests that people of hot climates may use words like “slightly cool” to describe their preferred thermal state. The relationship between draught sensation and indoor air velocity at different temperature ranges indicates that indoor air velocity had a significant influence over the occupants’ comfort sensation, and air velocities required by occupants increased with the increasing of operative temperatures. Thus, an effective way of natural ventilation which can create the preferred higher air movement is called for. Finally, the indoor set-point temperature of 26°C or even higher in air-conditioned buildings was confirmed as making people comfortable, which supports the regulation

  4. Air quality and ventilation fan control based on aerosol measurement in the bi-directional undersea Bømlafjord tunnel.

    PubMed

    Indrehus, Oddny; Aralt, Tor Tybring

    2005-04-01

    Aerosol, NO and CO concentration, temperature, air humidity, air flow and number of running ventilation fans were measured by continuous analysers every minute for a whole week for six different one-week periods spread over ten months in 2001 and 2002 at measuring stations in the 7860 m long tunnel. The ventilation control system was mainly based on aerosol measurements taken by optical scatter sensors. The ventilation turned out to be satisfactory according to Norwegian air quality standards for road tunnels; however, there was some uncertainty concerning the NO2 levels. The air humidity and temperature inside the tunnel were highly influenced by the outside metrological conditions. Statistical models for NO concentration were developed and tested; correlations between predicted and measured NO were 0.81 for a partial least squares regression (PLS1) model based on CO and aerosol, and 0.77 for a linear regression model based only on aerosol. Hence, the ventilation control system should not solely be based on aerosol measurements. Since NO2 is the hazardous polluter, modelling NO2 concentration rather than NO should be preferred in any further optimising of the ventilation control.

  5. Assessment of ventilation and indoor air pollutants in nursery and elementary schools in France.

    PubMed

    Canha, N; Mandin, C; Ramalho, O; Wyart, G; Ribéron, J; Dassonville, C; Hänninen, O; Almeida, S M; Derbez, M

    2016-06-01

    The aim of this study was to characterize the relationship between Indoor Air Quality (IAQ) and ventilation in French classrooms. Various parameters were measured over one school week, including volatile organic compounds, aldehydes, particulate matter (PM2.5 mass concentration and number concentration), carbon dioxide (CO2 ), air temperature, and relative humidity in 51 classrooms at 17 schools. The ventilation was characterized by several indicators, such as the air exchange rate, ventilation rate (VR), and air stuffiness index (ICONE), that are linked to indoor CO2 concentration. The influences of the season (heating or non-heating), type of school (nursery or elementary), and ventilation on the IAQ were studied. Based on the minimum value of 4.2 l/s per person required by the French legislation for mechanically ventilated classrooms, 91% of the classrooms had insufficient ventilation. The VR was significantly higher in mechanically ventilated classrooms compared with naturally ventilated rooms. The correlations between IAQ and ventilation vary according to the location of the primary source of each pollutant (outdoor vs. indoor), and for an indoor source, whether it is associated with occupant activity or continuous emission.

  6. Association of ventilation system type with SBS symptoms in office workers.

    PubMed

    Seppänen, O; Fisk, W J

    2002-06-01

    This paper provides a synthesis of current knowledge about the associations of ventilation system types in office buildings with sick building syndrome (SBS) symptoms and discusses potential explanations for the associations. Most studies completed to date indicate that relative to natural ventilation, air conditioning, with or without humidification, was consistently associated with a statistically significant increase in the prevalence of one or more SBS symptoms, by approximately 30 to 200%. In two of three analyses from a single study (assessments), symptom prevalences were also significantly higher in air-conditioned buildings than in buildings with simple mechanical ventilation and no humidification. The available data also suggest, with less consistency, an increase in risk of symptoms with simple mechanical ventilation relative to natural ventilation. Insufficient information was available for conclusions about the potential increased risk of SBS symptoms with humidification or recirculation of return air. The statistically significant associations of mechanical ventilation and air conditioning with SBS symptoms are much more frequent than expected from chance and also not likely to be a consequence of confounding by several potential personal, job, or building-related confounders. Multiple deficiencies in HVAC system design, construction, operation, or maintenance, including some which cause pollutant emissions from HVAC systems, may contribute to the increases in symptom prevalences but other possible reasons remain unclear.

  7. An air quality sensing system for cool air storage

    NASA Astrophysics Data System (ADS)

    Ngoy, T. J.; Joubert, T.-H.

    2016-02-01

    Cooling and ventilation systems play an important role in human occupied spaces. However, cooling using reversible air conditioners systems pollutes the environment and consumes a significant amount of energy. With global warming that experiences our environment, the large consumption of electrical energy and the operating instructions for reversible air conditioners, there is a need to find alternatives to those cooling systems. Hence this research project aims to investigate an air storage system, a microsystem reversible ventilation system using natural atmospheric air (renewable energy) for cooling at low consumption of energy. For the variation of the temperature range of comfort due to thermal heat produces by occupants, equipment and environment, an optimal transient automatic regulation of air flow as to be design in order to maintain the temperature of comfort in occupied spaces during peak hours.

  8. Hospital ventilation standards and energy conservation: chemical contamination of hospital air. Final report

    SciTech Connect

    Rainer, D.; Michaelsen, G.S.

    1980-03-01

    In an era of increasing energy conservation consciousness, a critical reassessment of the validity of hospital ventilation and thermal standards is made. If current standards are found to be excessively conservative, major energy conservation measures could be undertaken by rebalancing and/or modification of current HVAC systems. To establish whether or not reducing ventilation rates would increase airborne chemical contamination to unacceptable levels, a field survey was conducted to develop an inventory and dosage estimates of hospital generated airborne chemical contaminants to which patients, staff, and visitors are exposed. The results of the study are presented. Emphasis is on patient exposure, but an examination of occupational exposure was also made. An in-depth assessment of the laboratory air environment is documented. Housekeeping products used in survey hospitals, hazardous properties of housekeeping chemicals and probable product composition are discussed in the appendices.

  9. A novel evacuation passageway formed by a breathing air supply zone combined with upward ventilation

    NASA Astrophysics Data System (ADS)

    Gao, Ran; Li, Angui; Lei, Wenjun; Zhao, Yujiao; Zhang, Ying; Deng, Baoshun

    2013-10-01

    With the development of transportation, the tunnel has become one of the important facilities of railway, highway and subway transportation. However, fire hazards occurring inside the tunnel may incur huge numbers of casualties and property losses. In this paper, a breathing air supply zone combined with an upward ventilation assisted tunnel evacuation system (BTES) is introduced. It can be used to create a safe, smoke-free evacuation passageway out of the tunnel. The BTES is optimized to achieve high-performance. The impacts of heat release rates, fire source locations and fire detection times are also discussed. The carbon monoxide (CO) concentrations found when utilizing the BTES were significantly lower than that found when utilizing the traditional ventilation system. An obvious, clean evacuation passageway was created by the BTES. The maximum CO concentrations in the BTES evacuation passageway were below 10 PPM throughout the entire combustion process. A larger CO concentration gradient in the vertical direction was detected with the BTES than that found in other ventilation systems. This finding means that the lower part of the tunnel has a lower CO concentration with the BTES, which benefits the evacuation process. The impacts of fire source locations and fire detection times were tested to ensure the system reliability, and it was found that the performance of the BTES was not sensitive to them.

  10. 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.

  11. Vortex shedding induced energy harvesting from piezoelectric materials in heating, ventilation and air conditioning flows

    NASA Astrophysics Data System (ADS)

    Weinstein, L. A.; Cacan, M. R.; So, P. M.; Wright, P. K.

    2012-04-01

    A cantilevered piezoelectric beam is excited in a heating, ventilation and air conditioning (HVAC) flow. This excitation is amplified by the interactions between (a) an aerodynamic fin attached at the end of the piezoelectric cantilever and (b) the vortex shedding downstream from a bluff body placed in the air flow ahead of the fin/cantilever assembly. The positioning of small weights along the fin enables tuning of the energy harvester to operate at resonance for flow velocities from 2 to 5 m s-1, which are characteristic of HVAC ducts. In a 15 cm diameter air duct, power generation of 200 μW for a flow speed of 2.5 m s-1 and power generation of 3 mW for a flow speed of 5 m s-1 was achieved. These power outputs are sufficient to power a wireless sensor node for HVAC monitoring systems or other sensors for smart building technology.

  12. Study on air backflow in the goaf of working face with downward ventilation

    NASA Astrophysics Data System (ADS)

    Gao, Jianliang; Yang, Ming; Guo, Feipeng

    2011-10-01

    A commercial software package FLUENT is used for numerical simulation of the distribution of the air flow and gas in goaf of the working face with downward ventilation. With the increase of coal seam inclination, the phenomenon of airflow stagnant appears first on the upper part of the goaf, then backflow starts and eddy forms a certain distance away from the working face. When the coal seam slope increases to a certain angle, the air leakage in working face entirely reverses and flows into the gob from the bottom part of the mining face, and returns to working face from the upper part, particularly the upper corner of the working face. As the coal seam angle increases, the natural ventilation pressure in goaf increases too. When the natural ventilation pressure is less than the ventilation pressure differential in working face, the bigger of coal seam angle, the smaller of leakage air volume, and the closer of high-concentration gas migrate from goaf to working face. When the natural ventilation pressure in goaf is greater than the ventilation pressure differential in working face, with the increase of coal seam angle, the natural ventilation pressure and the air leakage volume increases, the range of leakage air backflow increases, high-concentration methane in the goaf will move to deep and total amount of gas in goaf decreases.

  13. Assessment of Natural Ventilation System for a Typical Residential House in Poland

    NASA Astrophysics Data System (ADS)

    Antczak-Jarząbska, Romana; Krzaczek, Marek

    2016-09-01

    The paper presents the research results of field measurements campaign of natural ventilation performance and effectiveness in a residential building. The building is located in the microclimate whose parameters differ significantly in relation to a representative weather station. The measurement system recorded climate parameters and the physical variables characterizing the air flow in the rooms within 14 days of the winter season. The measurement results showed that in spite of proper design and construction of the ventilation system, unfavorable microclimatic conditions that differed from the predicted ones caused significant reduction in the efficiency of the ventilation system. Also, during some time periods, external climate conditions caused an opposite air flow direction in the vent inlets and outlets, leading to a significant deterioration of air quality and thermal comfort measured by CO2 concentration and PMV index in a residential area.

  14. Carbon fibre composite for ventilation air methane (VAM) capture.

    PubMed

    Thiruvenkatachari, Ramesh; Su, Shi; Yu, Xin Xiang

    2009-12-30

    Coal mine methane (CMM) is not only a hazardous greenhouse gas but is also a wasted energy resource, if not utilised. This paper evaluates a novel adsorbent material developed for capturing methane from ventilation air methane (VAM) gas in underground coal mines. The adsorbent material is a honeycomb monolithic carbon fibre composite (HMCFC) consisting of multiple parallel flow-through channels and the material exhibits unique features including low pressure drop, good mechanical properties, ability to handle dust-containing gas streams, good thermal and electrical conductivity and selective adsorption of gases. During this study, a series of HMCFC adsorbents (using different types of carbon fibres) were successfully fabricated. Experimental data demonstrated the proof-of-concept of using the HMCFC adsorbent to capture methane from VAM gas. The adsorption capacity of the HMCFC adsorbent was twice that of commercial activated carbon. Methane concentration of 0.56% in the inlet VAM gas stream is reduced to about 0.011% after it passes through the novel carbon fibre composite adsorbent material at ambient temperature and atmospheric pressure. This amounts to a maximum capture efficiency of 98%. These encouraging laboratory scale studies have prompted further large scale trials and economic assessment.

  15. Operating experience review - Ventilation systems at Department of Energy Facilities

    SciTech Connect

    Not Available

    1994-05-01

    The Office of Special Projects (DP-35), formerly Office of Self-Assessment (DP-9), analyzed occurrences caused by problems with equipment and material and recommended the following systems for an in-depth study: (1) Selective Alpha Air Monitor (SAAM), (2) Emergency Diesel Generator, (3) Ventilation System, (4) Fire Alarm System. Further, DP-35 conducted an in-depth review of the problems associated with SAAM and with diesel generators, and made several recommendations. This study focusses on ventilation system. The intent was to determine the causes for the events related to these system that were reported in the Occurrence Reporting and Processing System (ORPS), to identify components that failed, and to provide technical information from the commercial and nuclear industries on the design, operation, maintenance, and surveillance related to the system and its components. From these data, sites can develop a comprehensive program of maintenance management, including surveillance, to avoid similar occurrences, and to be in compliance with the following DOE orders.

  16. Performance evaluation of a novel personalized ventilation-personalized exhaust system for airborne infection control.

    PubMed

    Yang, J; Sekhar, S C; Cheong, K W D; Raphael, B

    2015-04-01

    In the context of airborne infection control, it is critical that the ventilation system is able to extract the contaminated exhaled air within the shortest possible time. To minimize the spread of contaminated air exhaled by occupants efficiently, a novel personalized ventilation (PV)-personalized exhaust (PE) system has been developed, which aims to exhaust the exhaled air as much as possible from around the infected person (IP). The PV-PE system was studied experimentally for a particular healthcare setting based on a typical consultation room geometry and four different medical consultation positions of an IP and a healthy person (HP). Experiments using two types of tracer gases were conducted to evaluate two types of PE: Top-PE and Shoulder-PE under two different background ventilation systems: Mixing Ventilation and Displacement Ventilation. Personalized exposure effectiveness, intake fraction (iF) and exposure reduction (ε) were used as indices to evaluate the PV-PE system. The results show that the combined PV-PE system for the HP achieves the lowest intake fraction; and the use of PE system for the IP alone shows much better performance than using PV system for the HP alone.

  17. Dynamic Characteristics of Mechanical Ventilation System of Double Lungs with Bi-Level Positive Airway Pressure Model

    PubMed Central

    Shen, Dongkai; Zhang, Qian

    2016-01-01

    In recent studies on the dynamic characteristics of ventilation system, it was considered that human had only one lung, and the coupling effect of double lungs on the air flow can not be illustrated, which has been in regard to be vital to life support of patients. In this article, to illustrate coupling effect of double lungs on flow dynamics of mechanical ventilation system, a mathematical model of a mechanical ventilation system, which consists of double lungs and a bi-level positive airway pressure (BIPAP) controlled ventilator, was proposed. To verify the mathematical model, a prototype of BIPAP system with a double-lung simulators and a BIPAP ventilator was set up for experimental study. Lastly, the study on the influences of key parameters of BIPAP system on dynamic characteristics was carried out. The study can be referred to in the development of research on BIPAP ventilation treatment and real respiratory diagnostics. PMID:27660646

  18. Experimental study of a semi-passive ventilation grille with a feedback control system

    NASA Astrophysics Data System (ADS)

    D'Orazio, A.; Fontana, L.; Salata, F.

    2011-08-01

    The diffusion of window frames with low air permeability, due to the energy saving regulations, has implied in several cases the worsening of the indoor microclimate and air quality. On the other hand, air-tight window frames imply uncontrolled and too high air change rates. The mechanical ventilation not always is a practicable solution because of economic reasons and because it implies energy waste. Various Italian and European environmental and energetic laws take into consideration and promote the use of controlled natural ventilation, though this definition is not associated to well defined and tested technical solutions. An adequate solution can be achieved by using semi-passive self adjustable ventilation devices, able to ensure controlled changes of indoor air. In this paper, a semi-passive damper with a feedback control system is proposed and its behavior is investigated by means of experimental study. The presented semi-passive grille allows to control the air flow rate, injected into the room by natural or artificial pressure gradient, more effectively than the usual passive ventilation grilles made available by the present industrial production. However, since the semi-passive grille has a one-way flow, in the natural ventilation of a flat the proper functioning of the system could be ensured with a more complex configuration, with respect to the passive self-regulating grilles, able to limit the flow of fresh air in the presence of high levels of Δp; conversely, it could have widespread use in applications requiring a more accurate control of airflow in case of mechanical ventilation plants.

  19. Desiccant outdoor air preconditioners maximize heat recovery ventilation potentials

    SciTech Connect

    Meckler, M.

    1995-12-31

    Microorganisms are well protected indoors by the moisture surrounding them if the relative humidity is above 70%. They can cause many acute diseases, infections, and allergies. Humidity also has an effect on air cleanliness and causes the building structure and its contents to deteriorate. Therefore, controlling humidity is a very important factor to human health and comfort and the structural longevity of a building. To date, a great deal of research has been done, and is continuing, in the use of both solid and liquid desiccants. This paper introduces a desiccant-assisted system that combines dehumidification and mechanical refrigeration by means of a desiccant preconditioning module that can serve two or more conventional air-conditioning units. It will be demonstrated that the proposed system, also having indirect evaporative cooling within the preconditioning module, can reduce energy consumption and provide significant cost savings, independent humidity and temperature control, and, therefore, improved indoor air quality and enhanced occupant comfort.

  20. Development of a remotely controlled testing platform with low-drag air-ventilated hull

    NASA Astrophysics Data System (ADS)

    Matveev, Konstantin I.; Perry, Nicholaus I.; Mattson, Alexander W.; Chaney, Christopher S.

    2015-03-01

    This paper addresses the development and testing of a remotely controlled boat platform with an innovative air-ventilated hull. The application of air cavities on the underside of ship hulls is a promising means for reducing hydrodynamic drag and pollutant emissions and increasing marine transportation efficiency. Despite this concept's potential, design optimization and high-performance operation of novel air-cavity ships remain a challenging problem. Hull construction and sensor instrumentation of the model-scale air-cavity boat is described in the paper. The modular structure of the hull allows for easy modifications, and an electric propulsion unit enables self-propelled operation. The boat is controlled remotely via a radio transmission system. Results of initial tests are reported, including thrust, speed, and airflow rate in several loading conditions. The constructed platform can be used for optimizing air-cavity systems and testing other innovative hull designs. This system can be also developed into a high-performance unmanned boat.

  1. Fire protection countermeasures for containment ventilation systems

    SciTech Connect

    Alvares, N.J.; Beason, D.G.; Bergman, W.; Ford, H.W.; Lipska, A.E.

    1980-01-01

    The goal of this project is to find countermeasures to protect HEPA filters in exit ventilation ducts from the heat and smoke generated by fire. Several methods for partially mitigating the smoke exposure to the HEPA filters were identified through testing and analysis. These independently involve controlling the fuel, controlling the fire, and intercepting the smoke aerosol prior to its sorption on the HEPA filter. Exit duct treatment of aerosols is not unusual in industrial applications and involves the use of scrubbers, prefilters, and inertial impaction, depending on the size, distribution, and concentration of the subject aerosol. However, when these unmodified techniques were applied to smoke aerosols from fires on materials, common to experimental laboratories of LLNL, it was found they offered minimal protection to the HEPA filters. Ultimately, a continuous, movable, high-efficiency prefilter using modified commercial equipment was designed. This technique is capable of protecting HEPA filters over the total duration of the test fires. The reason for success involved the modificaton of the prefiltration media. Commercially available filter media has a particle sorption efficiency that is inversely proportional to media strength. To achieve properties of both efficiency and strength, we laminated rolling filter media with the desired properties. It is not true that the use of rolling prefilters solely to protect HEPA filters from fire-generated smoke aerosols is cost effective in every type of containment system, especially if standard fire-protection systems are available in the space. But in areas of high fire risk, where the potential fuel load is large and ignition sources are plentiful, the complication of a rolling prefilter in exit ventilation ducts to protect HEPA filters from smoke aerosols is definitely justified.

  2. Mobile zone, spray booth ventilation system. Final report

    SciTech Connect

    Not Available

    1994-04-26

    This concept endeavors to reduce the volume of air (to be treated) from spray paint booths, thereby increasing efficiency and improving air pollution abatement (VOC emissions especially). Most of the ventilation air is recycled through the booth to maintain laminar flow; the machinery is located on the supply side of the booth rather than on the exhaust side. 60 to 95% reduction in spray booth exhaust rate should result. Although engineering and production prototypes have been made, demand is low.

  3. B-Plant Canyon Ventilation Control System Description

    SciTech Connect

    MCDANIEL, K.S.

    1999-08-31

    Project W-059 installed a new B Plant Canyon Ventilation System. Monitoring and control of the system is implemented by the Canyon Ventilation Control System (CVCS). This document describes the CVCS system components which include a Programmable Logic Controller (PLC) coupled with an Operator Interface Unit (OIU) and application software. This document also includes an Alarm Index specifying the setpoints and technical basis for system analog and digital alarms.

  4. Demand controlled ventilating systems: Sensor market survey. Energy conservation in buildings and community systems programme, annex 18, December 1991

    NASA Astrophysics Data System (ADS)

    Raatschen, W.; Sjoegren, M.

    The subject of indoor and outdoor air quality has generated a great deal of attention in many countries. Areas of concern include outgassing of building materials as well as occupant-generated pollutants such as carbon dioxide, moisture, and odors. Progress has also been made towards addressing issues relating to the air tightness of the building envelope. Indoor air quality studies indicate that better control of supply flow rates as well as the air distribution pattern within buildings are necessary. One method of maintaining good indoor air quality without extensive energy consumption is to control the ventilation rate according to the needs and demands of the occupants, or to preserve the building envelope. This is accomplished through the use of demand controlled ventilating (DCV) systems. The specific objective of Annex 18 is to develop guidelines for demand controlled ventilating systems based on state of the art analyses, case studies on ventilation effectiveness, and proposed ventilation rates for different users in domestic, office, and school buildings.

  5. Comparison of Indoor Air Quality between 2 Ventilation Strategies in a Facility Housing Rhesus Macaques (Macaca mulatta)

    PubMed Central

    Monts de Oca, Nicole A; Laughlin, Mitzi; Jenkins, John; Lockworth, Cynthia R; Bolton, Iris D; Brammer, David W

    2015-01-01

    Adequate indoor-air quality (IAQ)—defined by the temperature, relative humidity, and the levels of carbon dioxide, small particles, and total volatile organic compounds (TVOC)—is crucial in laboratory animal facilities. The ventilation standards for controlling these parameters are not well defined. This study assessed the effect of 2 ventilation strategies on IAQ in 2 rooms housing rhesus macaques (Macaca mulatta). We hypothesized that using a demand-controlled ventilation (DCV) system with a baseline ventilation rate of less than 3 fresh-air changes per hour (ACH) would maintain IAQ comparable to or better than the traditional constant flow rate (CFR) system at 12 fresh ACH. During a 60-d study period, each of the 2 rooms operated 30 d on DCV and 30 d on CFR ventilation. In both rooms, temperatures remained more consistently within the established setpoint during the DCV phase than during the CFR phase. Relative humidity did not differ significantly between rooms or strategies. CO2 was lower during the CFR phase than DCV phase. Small-particle and TVOC levels were lower during CFR in the larger (3060 ft3) room but not the smaller (2340 ft3) room. During the DCV phase, the larger room was at the baseline airflow rate over 99% of the time and the smaller room over 96% of the time. The DCV strategy resulted in a baseline airflow rate of less than 3 ACH, which in turn provided acceptable IAQ over 96% of the time; higher ventilation rates were warranted only during sanitation periods. PMID:26424251

  6. Evaluation of Smoke Extraction Systems Versus Ventilation in Shipbuilding and Repair

    DTIC Science & Technology

    1990-01-01

    Shipyard Ventilation Planning System Database and Training Program. ● Panel Newsletter with Specific Governmental Activity Updates on Welding Fumes...Budgets to implement improvements Ž Scheduling responsibility above those of the trades. ● Computer Equipment, Software, and Database access to properly...commercial air cleaners can be applied to restaurants, lounges, bingo centers, taverns, bowling facilities, schools, hospitals, labs, offices, data process

  7. Forced-air warming and ultra-clean ventilation do not mix: an investigation of theatre ventilation, patient warming and joint replacement infection in orthopaedics.

    PubMed

    McGovern, P D; Albrecht, M; Belani, K G; Nachtsheim, C; Partington, P F; Carluke, I; Reed, M R

    2011-11-01

    We investigated the capacity of patient warming devices to disrupt the ultra-clean airflow system. We compared the effects of two patient warming technologies, forced-air and conductive fabric, on operating theatre ventilation during simulated hip replacement and lumbar spinal procedures using a mannequin as a patient. Infection data were reviewed to determine whether joint infection rates were associated with the type of patient warming device that was used. Neutral-buoyancy detergent bubbles were released adjacent to the mannequin's head and at floor level to assess the movement of non-sterile air into the clean airflow over the surgical site. During simulated hip replacement, bubble counts over the surgical site were greater for forced-air than for conductive fabric warming when the anaesthesia/surgery drape was laid down (p = 0.010) and at half-height (p < 0.001). For lumbar surgery, forced-air warming generated convection currents that mobilised floor air into the surgical site area. Conductive fabric warming had no such effect. A significant increase in deep joint infection, as demonstrated by an elevated infection odds ratio (3.8, p = 0.024), was identified during a period when forced-air warming was used compared to a period when conductive fabric warming was used. Air-free warming is, therefore, recommended over forced-air warming for orthopaedic procedures.

  8. A new system for continuous and remote monitoring of patients receiving home mechanical ventilation

    NASA Astrophysics Data System (ADS)

    Battista, L.

    2016-09-01

    Home mechanical ventilation is the treatment of patients with respiratory failure or insufficiency by means of a mechanical ventilator at a patient's home. In order to allow remote patient monitoring, several tele-monitoring systems have been introduced in the last few years. However, most of them usually do not allow real-time services, as they have their own proprietary communication protocol implemented and some ventilation parameters are not always measured. Moreover, they monitor only some breaths during the whole day, despite the fact that a patient's respiratory state may change continuously during the day. In order to reduce the above drawbacks, this work reports the development of a novel remote monitoring system for long-term, home-based ventilation therapy; the proposed system allows for continuous monitoring of the main physical quantities involved during home-care ventilation (e.g., differential pressure, volume, and air flow rate) and is developed in order to allow observations of different remote therapy units located in different places of a city, region, or country. The developed remote patient monitoring system is able to detect various clinical events (e.g., events of tube disconnection and sleep apnea events) and has been successfully tested by means of experimental tests carried out with pulmonary ventilators typically used to support sick patients.

  9. Experimental evaluation of the Skylab orbital workshop ventilation system concept

    NASA Technical Reports Server (NTRS)

    Allums, S. L.; Hastings, L. J.; Ralston, J. T.

    1972-01-01

    Extensive testing was conducted to evaluate the Orbital Workshop ventilation concept. Component tests were utilized to determine the relationship between operating characteristics at 1 and 0.34 atm. System tests were conducted at 1 atm within the Orbital Workshop full-scale mockup to assess delivered volumetric flow rate and compartment air velocities. Component tests with the Anemostat circular diffusers (plenum- and duct-mounted) demonstrated that the diffuser produced essentially equivalent airflow patterns and velocities in 1- and 0.34-atm environments. The tests also showed that the pressure drop across the diffuser could be scaled from 1 to 0.34 atm using the atmosphere pressure ratio. Fan tests indicated that the performance of a multiple, parallel-mounted fan cluster could be predicted by summing the single-fan flow rates at a given delta P.

  10. Multifamily Ventilation Retrofit Strategies

    SciTech Connect

    Ueno, K.; Lstiburek, J.; Bergey, D.

    2012-12-01

    In multifamily buildings, central ventilation systems often have poor performance, overventilating some portions of the building (causing excess energy use), while simultaneously underventilating other portions (causing diminished indoor air quality). BSC and Innova Services Corporation performed a series of field tests at a mid-rise test building undergoing a major energy audit and retrofit, which included ventilation system upgrades.

  11. VERIFICATION TESTING OF TECHNOLOGIES TO CLEAN OR FILTER VENTILATION AIR

    EPA Science Inventory

    Because of the importance of indoor air quality, Research Triangle Institute's Air Pollution Control Technology is adding indoor air products as a new technology category available for testing. This paper discusses RTI's participation in previous Environmental Technology Verifica...

  12. Utilization of ventilation air methane as a supplementary fuel at a circulating fluidized bed combustion boiler.

    PubMed

    You, Changfu; Xu, Xuchang

    2008-04-01

    Ventilation air methane (VAM) accounts for 60-80% of the total emissions from coal mining activities in China, which is of serious greenhouse gas concerns as well as a waste of valuable fuel sources. This contribution evaluates the use of the VAM utilization methods as a supplementary fuel at a circulating fluidized bed combustion boiler. The paper describes the system design and discusses some potential technical challenges such as methane oxidation rate, corrosion, and efficiency. Laboratory experimentation has shown that the VAM can be burnt completely in circulated fluidized bed furnaces, and the VAM oxidation does not obviously affect the boiler operation when the methane concentration is less than 0.6%. The VAM decreased the incomplete combustion loss for the circulating fluidized bed combustion furnace. The economic benefit from the coal saving insures that the proposed system is more economically feasible.

  13. Bio-inspired, efficient, artificial lung employing air as the ventilating gas.

    PubMed

    Potkay, Joseph A; Magnetta, Michael; Vinson, Abigail; Cmolik, Brian

    2011-09-07

    Artificial lungs have recently been utilized to rehabilitate patients suffering from lung diseases. However, significant advances in gas exchange, biocompatibility, and portability are required to realize their full clinical potential. Here, we have focused on the issues of gas exchange and portability and report a small-scale, microfabricated artificial lung that uses new mathematical modeling and a bio-inspired design to achieve oxygen exchange efficiencies much larger than current devices, thereby enabling air to be utilized as the ventilating gas. This advancement eliminates the need for pure oxygen required by conventional artificial lung systems and is achieved through a device with feature sizes and structure similar to that in the natural lung. This advancement represents a significant step towards creating the first truly portable and implantable artificial lung systems for the ambulatory care of patients suffering from lung diseases.

  14. Air Quality System (AQS)

    EPA Pesticide Factsheets

    The Air Quality System (AQS) database contains measurements of air pollutant concentrations from throughout the United States and its territories. The measurements include both criteria air pollutants and hazardous air pollutants.

  15. Indoor air pollutants, ventilation rate determinants and potential control strategies in Chinese dwellings: A literature review.

    PubMed

    Ye, Wei; Zhang, Xu; Gao, Jun; Cao, Guangyu; Zhou, Xiang; Su, Xing

    2017-05-15

    After nearly twenty years of rapid modernization and urbanization in China, huge achievements have transformed the daily lives of the Chinese people. However, unprecedented environmental consequences in both indoor and outdoor environments have accompanied this progress and have triggered public awareness and demands for improved living standards, especially in residential environments. Indoor pollution data measured for >7000 dwellings (approximately 1/3 were newly decorated and were tested for volatile organic compound (VOC) measurements, while the rest were tested for particles, phthalates and other semi-volatile organic compounds (SVOCs), moisture/mold, inorganic gases and radon) in China within the last ten years were reviewed, summarized and compared with indoor concentration recommendations based on sensory or health end-points. Ubiquitous pollutants that exceed the concentration recommendations, including particulate matter, formaldehyde, benzene and other VOCs, moisture/mold, inorganic gases and radon, were found, indicating a common indoor air quality (IAQ) issue in Chinese dwellings. With very little prevention, oral, inhalation and dermal exposure to those pollutants at unhealthy concentration levels is almost inevitable. CO2, VOCs, humidity and radon can serve as ventilation determinants, each with different ventilation demands and strategies, at typical occupant densities in China; and particle reduction should be a prerequisite for determining ventilation requirements. Two directional ventilation modes would have profound impacts on improving IAQ for Chinese residences are: 1) natural (or window) ventilation with an air cleaner and 2) mechanical ventilation with an air filtration unit, these two modes were reviewed and compared for their applicability and advantages and disadvantages for reducing human exposure to indoor air pollutants. In general, mode 2 can more reliably ensure good IAQ for occupants; while mode 1 is more applicable due to its low

  16. SITE TECHNOLOGY CAPSULE: SUBSURFACE VOLATILIZATION AND VENTILATION SYSTEM (SVVS)

    EPA Science Inventory

    The Subsurface Volatilization and Ventilation System is an integrated technology used for attacking all phases of volatile organic compound (VOC) contamination in soil and groundwater. The SVVS technology promotes insitu remediation of soil and groundwater contaminated with or-ga...

  17. SUBSURFACE VOLATIZATION AND VENTILATION SYSTEM (SVVS) - INNOVATIVE TECHNOLOGY REPORT

    EPA Science Inventory

    This report summarizes the findings associated with a Demonstration Test of Environmental Improvement Technologies’ (EIT) Subsurface Volatilization and Ventilation System (SVVS) process. The technology was evaluated under the EPA Superfund Innovative Technology Evaluation (SITE) ...

  18. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Ventilation of air conditioning systems serving the chemical laboratory shall be designed so that air cannot... 46 Shipping 7 2012-10-01 2012-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST....15-5 Ventilation. (a) Operations, reactions or experiments which produce toxic, noxious or...

  19. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Ventilation of air conditioning systems serving the chemical laboratory shall be designed so that air cannot... 46 Shipping 7 2011-10-01 2011-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST....15-5 Ventilation. (a) Operations, reactions or experiments which produce toxic, noxious or...

  20. The effect of ventilation protocols on airborne particulate matter in subway systems.

    PubMed

    Moreno, Teresa; Reche, Cristina; Minguillón, Maria Cruz; Capdevila, Marta; de Miguel, Eladio; Querol, Xavier

    2017-04-15

    As part of the European-funded IMPROVE LIFE project work programme experiments were performed in the Barcelona Metro system with the objective of better understanding the relationship between ventilation and air quality. The results demonstrate that tunnel ventilation plays an extremely important role in maintaining cleaner air and is capable of reducing both inhalable particulate matter (PM) mass and particle number concentration (>0.3μm) on platforms by over 50%, even in the presence of full-length platform screen doors. Another key influence on platform air quality is the chosen combination of fan power and forced air flow direction (impulsion of outdoor ambient air or extraction of subway indoor air): cleaner platform air was achieved using platform impulsion at higher power settings designed to ameliorate high summer temperatures underground. Reversing platform air flow from impulsion to extraction produced an immediate deterioration in PM air quality, most notably if the higher power setting was maintained, when an especially marked increase in numbers of very fine (submicron) particles was observed and attributed to tunnel air being drawn into the platform. At night, in the absence of trains and platform ventilation, platform air quality improves when tunnel fans are working at reduced power, whatever the flow direction (impulsion/extraction). Inside the air conditioned Barcelona Metro trains (where underground commuters spend most of their time) air quality is markedly better than on the platform, and unchanged A/C filters were observed capable of maintaining a similar reduction in inside train PM for at least three months.

  1. 46 CFR 105.25-7 - Ventilation systems for cargo tank or pumping system compartment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Ventilation systems for cargo tank or pumping system... Requirements-When Cargo Tanks Are Installed Below Decks § 105.25-7 Ventilation systems for cargo tank or... ventilation outlets shall terminate more than 10 feet from any opening to the interior of the vessel...

  2. 46 CFR 105.25-7 - Ventilation systems for cargo tank or pumping system compartment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Ventilation systems for cargo tank or pumping system... Requirements-When Cargo Tanks Are Installed Below Decks § 105.25-7 Ventilation systems for cargo tank or... ventilation outlets shall terminate more than 10 feet from any opening to the interior of the vessel...

  3. 46 CFR 105.25-7 - Ventilation systems for cargo tank or pumping system compartment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Ventilation systems for cargo tank or pumping system... Requirements-When Cargo Tanks Are Installed Below Decks § 105.25-7 Ventilation systems for cargo tank or... ventilation outlets shall terminate more than 10 feet from any opening to the interior of the vessel...

  4. Effect of outside air ventilation rate on volatile organic compound concentrations in a call center

    NASA Astrophysics Data System (ADS)

    Hodgson, A. T.; Faulkner, D.; Sullivan, D. P.; DiBartolomeo, D. L.; Russell, M. L.; Fisk, W. J.

    A study of the relationship between outside air ventilation rate and concentrations of volatile organic compounds (VOCs) generated indoors was conducted in a call center office building. The building, with two floors and a total floor area of 4600 m 2, is located in the San Francisco Bay Area, CA. Ventilation rates were manipulated with the building's four air handling units (AHUs). VOC and CO 2 concentrations in the AHU returns were measured on 7 days during a 13-week period. VOC emission factors were determined for individual zones on days when they were operating at near steady-state conditions. The emission factor data were subjected to principal component (PC) analysis to identify groups of co-varying compounds. Potential sources of the PC vectors were ascribed based on information from the literature. The per occupant CO 2 generation rates were 0.0068-0.0092 l s -1. The per occupant isoprene generation rates of 0.2-0.3 mg h -1 were consistent with the value predicted by mass balance from breath concentration and exhalation rate. The relationships between indoor minus outdoor VOC concentrations and ventilation rate were qualitatively examined for eight VOCs. Of these, acetaldehyde and hexanal, which likely were associated with material sources, and decamethylcyclopentasiloxane, associated with personal care products, exhibited general trends of higher concentrations at lower ventilation rates. For other compounds, a clear inverse relationship between VOC concentrations and ventilation was not observed. The net concentration of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate isomers, examples of low-volatility compounds, changed very little with ventilation likely due to sorption and re-emission effects. These results illustrate that the efficacy of ventilation for controlling VOC concentrations can vary considerably depending upon the operation of the building, the pollutant sources and the physical and chemical processes affecting the pollutants. Thus, source

  5. Ventilation Transport Trade Study for Future Space Suit Life Support Systems

    NASA Technical Reports Server (NTRS)

    Kempf, Robert; Vogel, Matthew; Paul, Heather L.

    2008-01-01

    A new and advanced portable life support system (PLSS) for space suit surface exploration will require a durable, compact, and energy efficient system to transport the ventilation stream through the space suit. Current space suits used by NASA circulate the ventilation stream via a ball-bearing supported centrifugal fan. As NASA enters the design phase for the next generation PLSS, it is necessary to evaluate available technologies to determine what improvements can be made in mass, volume, power, and reliability for a ventilation transport system. Several air movement devices already designed for commercial, military, and space applications are optimized in these areas and could be adapted for EVA use. This paper summarizes the efforts to identify and compare the latest fan and bearing technologies to determine candidates for the next generation PLSS.

  6. Assessment of Indoor Air Quality Benefits and Energy Costs of Mechanical Ventilation

    SciTech Connect

    Logue, J.M.; Price, P.N.; Sherman, M.H.; Singer, B.C.

    2011-07-01

    Intake of chemical air pollutants in residences represents an important and substantial health hazard. Sealing homes to reduce air infiltration can save space conditioning energy, but can also increase indoor pollutant concentrations. Mechanical ventilation ensures a minimum amount of outdoor airflow that helps reduce concentrations of indoor emitted pollutants while requiring some energy for fan(s) and thermal conditioning of the added airflow. This work demonstrates a physics based, data driven modeling framework for comparing the costs and benefits of whole-house mechanical ventilation and applied the framework to new California homes. The results indicate that, on a population basis, the health benefits from reduced exposure to indoor pollutants in New California homes are worth the energy costs of adding mechanical ventilation as specified by ASHRAE Standard 62.2.This study determines the health burden for a subset of pollutants in indoor air and the costs and benefits of ASHRAE's mechanical ventilation standard (62.2) for new California homes. Results indicate that, on a population basis, the health benefits of new home mechanical ventilation justify the energy costs.

  7. Should Title 24 Ventilation Requirements Be Amended to include an Indoor Air Quality Procedure?

    SciTech Connect

    Dutton, Spencer M.; Mendell, Mark J.; Chan, Wanyu R.

    2013-05-13

    Minimum outdoor air ventilation rates (VRs) for buildings are specified in standards, including California?s Title 24 standards. The ASHRAE ventilation standard includes two options for mechanically-ventilated buildings ? a prescriptive ventilation rate procedure (VRP) that specifies minimum VRs that vary among occupancy classes, and a performance-based indoor air quality procedure (IAQP) that may result in lower VRs than the VRP, with associated energy savings, if IAQ meeting specified criteria can be demonstrated. The California Energy Commission has been considering the addition of an IAQP to the Title 24 standards. This paper, based on a review of prior data and new analyses of the IAQP, evaluates four future options for Title 24: no IAQP; adding an alternate VRP, adding an equivalent indoor air quality procedure (EIAQP), and adding an improved ASHRAE-like IAQP. Criteria were established for selecting among options, and feedback was obtained in a workshop of stakeholders. Based on this review, the addition of an alternate VRP is recommended. This procedure would allow lower minimum VRs if a specified set of actions were taken to maintain acceptable IAQ. An alternate VRP could also be a valuable supplement to ASHRAE?s ventilation standard.

  8. Environmental Technology Verification: Supplement to Test/QA Plan for Biological and Aerosol Testing of General Ventilation Air Cleaners; Bioaerosol Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Air Cleaners

    EPA Science Inventory

    The Air Pollution Control Technology Verification Center has selected general ventilation air cleaners as a technology area. The Generic Verification Protocol for Biological and Aerosol Testing of General Ventilation Air Cleaners is on the Environmental Technology Verification we...

  9. Implementation of PFC (Predictive Functional Control) in a PLC (Programmable Logic Controller) for a HVAC (Heating, Ventilation and Air Conditioning) system

    NASA Astrophysics Data System (ADS)

    Kreutz, M.; Richalet, J.; Mocha, K.; Haber, R.

    2014-12-01

    HVAC systems of industrial buildings consume a lot of energy. Therefore it is important to know the performance of these systems and strategies to optimize the hardware and the control. Tackling the temperature control of the HVAC system promises quick savings by tuning the control within specified tolerance limits, which mostly can be done by low investment. This paper mainly deals with the implementation strategy of a new controller in a PLC using the predictive functional control for temperature control. The different stages of the implementation from the simulation over the SCL code till to the real-time operation are presented. A bumpless switch between the PI(D) and the PFC control was realized, as well.

  10. Effect of outside air ventilation rate on VOC concentrations and emissions in a call center

    SciTech Connect

    Hodgson, A.T.; Faulkner, D.; Sullivan, D.P.; DiBartolomeo, D.L.; Russell, M.L.; Fisk, W.J.

    2002-01-01

    A study of the relationship between outside air ventilation rate and concentrations of VOCs generated indoors was conducted in a call center. Ventilation rates were manipulated in the building's four air handling units (AHUs). Concentrations of VOCs in the AHU returns were measured on 7 days during a 13-week period. Indoor minus outdoor concentrations and emission factors were calculated. The emission factor data was subjected to principal component analysis to identify groups of co-varying compounds based on source type. One vector represented emissions of solvents from cleaning products. Another vector identified occupant sources. Direct relationships between ventilation rate and concentrations were not observed for most of the abundant VOCs. This result emphasizes the importance of source control measures for limiting VOC concentrations in buildings.

  11. Pneumomediastinum and retroperitoneal air after removal of papillomas with the microdebrider and jet ventilation.

    PubMed Central

    Sims, H. Steven; Lertsburapa, Keith

    2007-01-01

    OBJECTIVE: To discuss the complication of pneumothorax from alveolar rupture after transtracheal high-frequency jet ventilation and to present a case of pneumothorax, pneumomediastinum and pneumoperitoneum after jet ventilation coupled with use of the microdebrider. METHOD: Detailed case report. RESULTS: Unilateral pnuemothorax, subcutaneous emphysema, pneumomediastinum and retroperitoneal air discovered after jet ventilation for removal of airway papillomas resolved with conservative management. DISCUSSION: We discuss the difference between the respective patterns of air seepage in a peripheral alveolar injury versus a probable microperforation in the trachea. We also review the epidemiology of this rare disorder and its incidence in the African-American community. CONCLUSION: The recurrent nature of this disorder mandates multiple surgical procedures. Great care must be taken to eradicate disease and avoid complications. Pneumomediastinum in this setting can be managed conservatively. Images Figure 1 Figure 2 PMID:17913120

  12. Energy Code Enforcement Training Manual : Covering the Washington State Energy Code and the Ventilation and Indoor Air Quality Code.

    SciTech Connect

    Washington State Energy Code Program

    1992-05-01

    This manual is designed to provide building department personnel with specific inspection and plan review skills and information on provisions of the 1991 edition of the Washington State Energy Code (WSEC). It also provides information on provisions of the new stand-alone Ventilation and Indoor Air Quality (VIAQ) Code.The intent of the WSEC is to reduce the amount of energy used by requiring energy-efficient construction. Such conservation reduces energy requirements, and, as a result, reduces the use of finite resources, such as gas or oil. Lowering energy demand helps everyone by keeping electricity costs down. (It is less expensive to use existing electrical capacity efficiently than it is to develop new and additional capacity needed to heat or cool inefficient buildings.) The new VIAQ Code (effective July, 1991) is a natural companion to the energy code. Whether energy-efficient or not, an homes have potential indoor air quality problems. Studies have shown that indoor air is often more polluted than outdoor air. The VIAQ Code provides a means of exchanging stale air for fresh, without compromising energy savings, by setting standards for a controlled ventilation system. It also offers requirements meant to prevent indoor air pollution from building products or radon.

  13. CFD-based design of the ventilation system for the PHENIX detector

    SciTech Connect

    Parietti, L.; Martin, R.A.; Gregory, W.S.

    1996-10-01

    The three-dimensional flow and thermal fields surrounding the large PHENIX sub-atomic particle detector enclosed in the Major Facility Hall are simulated numerically in this study using the CFX finite volume, commercial, computer code. The predicted fields result from the interaction of an imposed downward ventilation system cooling flow and a buoyancy-driven thermal plume rising from the warm detector. An understanding of the thermal irregularities on the surface of the detector and in the flow surrounding is needed to assess the potential for adverse thermal expansion effects in detector subsystems, and to prevent ingestion of electronics cooling air from hot spots. With a computational model of the thermal fields on and surrounding the detector, HVAC engineers can evaluate and improve the ventilation system design prior to the start of construction. This paper summarizes modeling and results obtained for a conceptual MFH ventilation scheme.

  14. 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…

  15. 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.…

  16. 10 CFR 429.43 - Commercial heating, ventilating, air conditioning (HVAC) equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ensure that— (i) Any represented value of energy consumption or other measure of energy usage of a basic... 10 Energy 3 2012-01-01 2012-01-01 false Commercial heating, ventilating, air conditioning (HVAC) equipment. 429.43 Section 429.43 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION,...

  17. 10 CFR 429.43 - Commercial heating, ventilating, air conditioning (HVAC) equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ensure that— (i) Any represented value of energy consumption or other measure of energy usage of a basic... 10 Energy 3 2013-01-01 2013-01-01 false Commercial heating, ventilating, air conditioning (HVAC) equipment. 429.43 Section 429.43 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION,...

  18. 10 CFR 429.43 - Commercial heating, ventilating, air conditioning (HVAC) equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... of energy consumption or other measure of energy usage of a basic model for which consumers would... 10 Energy 3 2014-01-01 2014-01-01 false Commercial heating, ventilating, air conditioning (HVAC) equipment. 429.43 Section 429.43 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION,...

  19. FRACTIONAL AEROSOL FILTRATION EFFICIENCY OF IN-DUCT VENTILATION AIR CLEANERS

    EPA Science Inventory

    The filtration efficiency of ventilation air cleaners is highly particle-size dependent over the 0.01 to 3 μm diameter size range. Current standardized test methods, which determine only overall efficiencies for ambient aerosol or other test aerosols, provide data of limited util...

  20. 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…

  1. 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…

  2. Anaesthesia ventilators

    PubMed Central

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-01-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV). PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits. PMID:24249886

  3. Indoor air quality, ventilation and health symptoms in schools: an analysis of existing information.

    PubMed

    Daisey, J M; Angell, W J; Apte, M G

    2003-03-01

    We reviewed the literature on Indoor Air Quality (IAQ), ventilation, and building-related health problems in schools and identified commonly reported building-related health symptoms involving schools until 1999. We collected existing data on ventilation rates, carbon dioxide (CO2) concentrations and symptom-relevant indoor air contaminants, and evaluated information on causal relationships between pollutant exposures and health symptoms. Reported ventilation and CO2 data strongly indicate that ventilation is inadequate in many classrooms, possibly leading to health symptoms. Adequate ventilation should be a major focus of design or remediation efforts. Total volatile organic compounds, formaldehyde (HCHO) and microbiological contaminants are reported. Low HCHO concentrations were unlikely to cause acute irritant symptoms (<0.05 ppm), but possibly increased risks for allergen sensitivities, chronic irritation, and cancer. Reported microbiological contaminants included allergens in deposited dust, fungi, and bacteria. Levels of specific allergens were sufficient to cause symptoms in allergic occupants. Measurements of airborne bacteria and airborne and surface fungal spores were reported in schoolrooms. Asthma and 'sick building syndrome' symptoms are commonly reported. The few studies investigating causal relationships between health symptoms and exposures to specific pollutants suggest that such symptoms in schools are related to exposures to volatile organic compounds (VOCs), molds and microbial VOCs, and allergens.

  4. A novel fiber-optic measurement system for the evaluation of performances of neonatal pulmonary ventilators

    NASA Astrophysics Data System (ADS)

    Battista, L.; Scorza, A.; Botta, F.; Sciuto, S. A.

    2016-02-01

    Published standards for the performance evaluation of pulmonary ventilators are mainly directed to manufacturers rather than to end-users and often considered inadequate or not comprehensive. In order to contribute to overcome the problems above, a novel measurement system was proposed and tested with waveforms of mechanical ventilation by means of experimental trials carried out with infant ventilators typically used in neonatal intensive care units: the main quantities of mechanical ventilation in newborns are monitored, i.e. air flow rate, differential pressure and volume from infant ventilator are measured by means of two novel fiber-optic sensors (OFSs) developed and characterized by the authors, while temperature and relative humidity of air mass are obtained by two commercial transducers. The proposed fiber-optic sensors (flow sensor Q-OFS, pressure sensor P-OFS) showed measurement ranges of air flow and pressure typically encountered in neonatal mechanical ventilation, i.e. the air flow rate Q ranged from 3 l min-1 to 18 l min-1 (inspiratory) and from  -3 l min-1 to  -18 l min-1 (expiratory), the differential pressure ΔP ranged from  -15 cmH2O to 15 cmH2O. In each experimental trial carried out with different settings of the ventilator, outputs of the OFSs are compared with data from two reference sensors (reference flow sensor RF, reference pressure sensor RP) and results are found consistent: flow rate Q showed a maximum error between Q-OFS and RF up to 13 percent, with an output ratio Q RF/Q OFS of not more than 1.06  ±  0.09 (least square estimation, 95 percent confidence level, R 2 between 0.9822 and 0.9931). On the other hand the maximum error between P-OFS and RP on differential pressure ΔP was lower than 10 percent, with an output ratio ΔP RP/ΔP OFS between 0.977  ±  0.022 and 1.0  ±  0.8 (least square estimation, 95 percent confidence level, R 2 between 0.9864 and 0.9876). Despite the possible improvements

  5. Evaluating Ventilation Systems for Existing Homes

    SciTech Connect

    Aldrich, R.; Arena, L.

    2013-02-01

    During the course of this project, an affordable and high performance ductwork system to directly address the problems of thermal losses, poor efficiency, and air leakage was designed. To save space and enable direct connections between different floors of the building, the ductwork system was designed in such a way that it occupied interior or exterior frame wall cavities. The ductwork system satisfied building regulations for structural support when bridging multiple floors, the spread of fire and smoke, and insulation to reduce the heat flow into or out of the building. Retrofits of urban residential buildings will be the main focus for the application of this ductwork system. Highly reflective foils and insulating materials were used to aid in the increase of the overall R-value of the ductwork itself and the wall assembly. It is expected that the proposed system will increase the efficiency of the HVAC system and the thermal resistance of the building envelope. The performance of the proposed ductwork design was numerically evaluated in a number of different ways. Our results indicate that the duct method is a very cost attractive alternative to the conventional method.

  6. Ventilation Model

    SciTech Connect

    V. Chipman

    2002-10-05

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. The purposes of Revision 01 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of the discretization (Section 6.2.3.1), and the downstream applicability of the model results (i.e. wall heat fractions) to initialize post

  7. Numerical investigation and recommendations for push-pull ventilation systems.

    PubMed

    Chern, Ming-Jyh; Ma, Chen-Hsuan

    2007-03-01

    This study presents numerical simulations of push-pull ventilation systems. A push-pull system is a device commonly used in capturing pollutants from large tanks used in industrial chemical processes. An air jet is blown from one side of a tank and collected by an exhaust hood on the opposite side of the tank. In this study, a finite volume model coupled with the standard k -epsilon turbulent model is employed to describe the flow structures and characteristics. Moreover, the turbulence mass transfer equation is adopted to show the concentration distribution above the open surface tank. All the flow fields can be classified according to four dominant modes, i.e., dispersion, transition, encapsulation, and strong suction. The push and pull flow velocities should be adjusted into encapsulation and strong suction modes to ensure all pollutants can be captured by the exhaust hood. Other geometric parameters such as the flange size, pull-channel size, offset distance, etc., also influence the flow characteristics. For a variety of lengths of tanks and pollutant evaporation velocities, the push and pull flow velocity must be matched to achieve optimal operation. Furthermore, the flange size and other parameters are determined to enhance the capture efficiency of the push-pull system. Recommendations for design guidelines are introduced in this study.

  8. Energy recovery ventilator

    SciTech Connect

    Schneider, S. L.; Dravnieks, K.

    1985-04-30

    An energy recovery ventilator adapted to be mounted on a roof and adapted to be connected to the outlet of an exhaust air duct of a building ventilation system and the inlet of an air supply duct of a building ventilation system. The energy recovery ventilator includes a housing having an exhaust air chamber and a supply air chamber separated by a divider wall. A circular heat transfer wheel is position in the housing, a portion of the wheel being housed in the exhaust air chamber and a second portion of the wheel being housed in the supply air chamber, and the heat transfer wheel is caused to rotate about a central axis. An exhaust fan is housed in the exhaust air chamber and causes exhaust air to be pulled through the exhaust air duct and the heat transfer wheel and to be exhausted from the housing. A supply air fan is housed in the supply air housing above the heat transfer wheel, and causes outside air to be drawn into the supply air chamber and to be forced through the heat transfer wheel into the air supply duct.

  9. Measurement of airflow and pressure characteristics of a fan built in a car ventilation system

    NASA Astrophysics Data System (ADS)

    Pokorný, Jan; Poláček, Filip; Fojtlín, Miloš; Fišer, Jan; Jícha, Miroslav

    2016-03-01

    The aim of this study was to identify a set of operating points of a fan built in ventilation system of our test car. These operating points are given by the fan pressure characteristics and are defined by a pressure drop of the HVAC system (air ducts and vents) and volumetric flow rate of ventilation air. To cover a wide range of pressure drops situations, four cases of vent flaps setup were examined: (1) all vents opened, (2) only central vents closed (3) only central vents opened and (4) all vents closed. To cover a different volumetric flows, the each case was measured at least for four different speeds of fan defined by the fan voltage. It was observed that the pressure difference of the fan is proportional to the fan voltage and strongly depends on the throttling of the air distribution system by the settings of the vents flaps. In case of our test car we identified correlations between volumetric flow rate of ventilation air, fan pressure difference and fan voltage. These correlations will facilitate and reduce time costs of the following experiments with this test car.

  10. Local ventilation for powder handling--combination of local supply and exhaust air.

    PubMed

    Heinonen, K; Kulmala, I; Säämänen, A

    1996-04-01

    The performance of a modified local ventilation unit equipped with local supply and exhaust ventilation was evaluated during the manual handling of flour additive powder. The investigation tested five different configurations to study the effects of the exhaust opening location and local supply air on worker exposure. The measurements were done under controlled conditions in a test room. The breathing zone (BZ) dust concentration was measured by gravimetric sampling and real time monitoring. The different local ventilation configurations were also modeled numerically using computational fluid dynamics. Without local ventilation the average BZ dust concentration was 42 mg/m3. With local exhaust only the exposure was reduced below 1 mg/m3. The addition of local supply air further reduced the exposure to below 0.5 mg/m3. The lowest results were achieved by locating two exhaust openings on either side of the contaminant source combined with local supply air. With this configuration the average BZ exposure was only 0.08 mg/m3, a reduction of 99.8%. Numerical simulations also gave useful information about the airflow fields in stationary conditions. However, the worker's exposure was greatly affected by body movements, and this was not possible to simulate numerically. The results of this investigation can be useful when controlling dust exposure in manual powder handling operations.

  11. Dehumidification Performance of Humidity Control System with Double Ventilation Sorbent Rotor

    NASA Astrophysics Data System (ADS)

    Takaki, Sadao; Horibe, Akihiko; Haruki, Naoto; Nishina, Yuki; Inaba, Hideo

    The desiccant air-conditioning will be suitable for effective use of the exhaust heat. We have reported high dehumidification efficiency of the proposed system that is composed of a sorbent rotor and a refrigerating cycle. In this study, to improve the sorption efficiency of the rotor, the double ventilation rotor is proposed. After the processing air is dehumidified at the sorption area 1 of the rotor, the air is cooled and has higher relative humidity. And then, the air is blew into the sorption area 2 from the rotor opposite. The double ventilation characteristics on the influence of the division area of the rotor, the flow rate, the recovery temperature, and the temperature of the air cooler were investigated. As a result, the behavior of the double ventilation rotor is clarified and it is found that the quantity of dehumidification of the rotor is greater in the case of 1:1:2 (sorption(1): sorption(2): desorption ) division rate of the rotor than that of 1:1:1.

  12. Estimating the energy-saving benefit of reduced-flow and/or multi-speed commercial kitchen ventilation systems

    SciTech Connect

    Fisher, D.; Schmid, F.; Spata, A.J.

    1999-07-01

    Kitchen exhaust ventilation systems are recognized as a major energy user within commercial food service facilities and restaurants. Minimizing the design ventilation rate of an appliance/hood system by optimizing hood performance in the laboratory is a viable strategy for reducing the makeup air heating and cooling loads as well as the exhaust and supply fan energy. Cutting back the exhaust flow under conditions of noncooking (appliance idle) can further reduce the energy load associated with a kitchen ventilation system. An optimized, two-speed exhaust system was installed within the scope of an energy-efficient, quick service restaurant (QSR) design and demonstration project. This paper evaluates the energy benefit of this variable-flow strategy as well as the savings associated with reducing the design ventilation rate (compared to an off-the-shelf exhaust hood). The paper describes a new public-domain software tool for estimating heating and cooling loads associated with the makeup air requirements of commercial kitchens. This bin-based software provides ASHRAE engineers with an alternative to hand calculations or more sophisticated hour-by-hour simulation. The dramatic impact that both makeup air set point and geographic location have on the outdoor air load is illustrated. The paper concludes with an industry-wide projection of energy savings associated with optimizing the design and operation of commercial kitchen ventilation (CKV) systems.

  13. An integrated evaluation study of the ventilation rate, the exposure and the indoor air quality in naturally ventilated classrooms in the Mediterranean region during spring.

    PubMed

    Dorizas, Paraskevi Vivian; Assimakopoulos, Margarita-Niki; Helmis, Constantinos; Santamouris, Mattheos

    2015-01-01

    Ventilation rates and indoor air pollutants have been extensively monitored in nine naturally ventilated primary schools of Athens, Greece during spring. The ventilation rates and pollutant levels were studied during the teaching and non-teaching periods and ventilation profiles were created for each of the schools. The median ventilation rates per school ranged between 0.7 and 8 ACH while the average ventilation rate in all schools (11.7l/s/p) was greater than the minimum recommended rates by ASHRAE for school classrooms. The average carbon dioxide (CO2) concentrations per school varied between 893 and 2082ppm, while the majority of the cases were slightly above the recommended limit values. CO2 concentrations were also positively correlated to the number of students and negatively correlated to the ventilation rates. Particles of several size ranges (PM10, PM5, PM2.5, PM1, PM0.5 and UFP) were also measured and analyzed. PM10 concentrations exceeded the recommended limit values by more than 10 times for the majority of the cases. There were also many cases that the PM2.5 concentrations exceeded their limit values. PM concentrations were significantly affected by the ventilation rates and the presence of students. All of the measured particle sizes were greater during teaching than the non-teaching hours. For most of the cases the indoor to outdoor (I/O) concentrations ratios of PM10 and PM2.5 were much greater than one, indicating that the indoor environment was being mostly affected by indoor sources instead of the outdoor air. Furthermore it was found that chalk and marker boards' usage significantly affect indoor pollutant concentrations. Overall, the measured levels of exposure were for most of the cases greater than the recommended guideline values due to the intense presence of indoor pollution sources, even though the ventilation rates were in general satisfactory.

  14. Aerodynamic characteristics of the ventilated design for flapping wing micro air vehicle.

    PubMed

    Zhang, G Q; Yu, S C M

    2014-01-01

    Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the "ventilation" in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds.

  15. SpaceX Dragon Air Circulation System

    NASA Technical Reports Server (NTRS)

    Hernandez, Brenda; Piatrovich, Siarhei; Prina, Mauro

    2011-01-01

    The Dragon capsule is a reusable vehicle being developed by Space Exploration Technologies (SpaceX) that will provide commercial cargo transportation to the International Space Station (ISS). Dragon is designed to be a habitable module while it is berthed to ISS. As such, the Dragon Environmental Control System (ECS) consists of pressure control and pressure equalization, air sampling, fire detection, illumination, and an air circulation system. The air circulation system prevents pockets of stagnant air in Dragon that can be hazardous to the ISS crew. In addition, through the inter-module duct, the air circulation system provides fresh air from ISS into Dragon. To utilize the maximum volume of Dragon for cargo packaging, the Dragon ECS air circulation system is designed around cargo rack optimization. At the same time, the air circulation system is designed to meet the National Aeronautics Space Administration (NASA) inter-module and intra-module ventilation requirements and acoustic requirements. A flight like configuration of the Dragon capsule including the air circulation system was recently assembled for testing to assess the design for inter-module and intra-module ventilation and acoustics. The testing included the Dragon capsule, and flight configuration in the pressure section with cargo racks, lockers, all of the air circulation components, and acoustic treatment. The air circulation test was also used to verify the Computational Fluid Dynamics (CFD) model of the Dragon capsule. The CFD model included the same Dragon internal geometry that was assembled for the test. This paper will describe the Dragon air circulation system design which has been verified by testing the system and with CFD analysis.

  16. 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.

  17. Water spray ventilator system for continuous mining machines

    DOEpatents

    Page, Steven J.; Mal, Thomas

    1995-01-01

    The invention relates to a water spray ventilator system mounted on a continuous mining machine to streamline airflow and provide effective face ventilation of both respirable dust and methane in underground coal mines. This system has two side spray nozzles mounted one on each side of the mining machine and six spray nozzles disposed on a manifold mounted to the underside of the machine boom. The six spray nozzles are angularly and laterally oriented on the manifold so as to provide non-overlapping spray patterns along the length of the cutter drum.

  18. Air compressor battery duration with mechanical ventilation in a field anesthesia machine.

    PubMed

    Szpisjak, Dale F; Giberman, Anthony A

    2015-05-01

    Compressed air to power field anesthesia machine ventilators may be supplied by air compressor with battery backup. This study determined the battery duration when the compPAC ventilator's air compressor was powered by NiCd battery to ventilate the Vent Aid Training Test Lung modeling high (HC = 0.100 L/cm H2O) and low (LC = 0.020 L/cm H2O) pulmonary compliance. Target tidal volumes (VT) were 500, 750, and 1,000 mL. Respiratory rate = 10 bpm, inspiratory-to-expiratory time ratio = 1:2, and fresh gas flow = 1 L/min air. N = 5 in each group. Control limits were determined from the first 150 minutes of battery power for each run and lower control limit = mean VT - 3SD. Battery depletion occurred when VT was below the lower control limit. Battery duration ranged from 185.8 (±3.2) minutes in the LC-1000 group to 233.3 (±3.6) minutes in the HC-750 group. Battery duration of the LC-1000 group was less than all others (p = 0.027). The differences among the non-LC-1000 groups were not clinically significant.

  19. Simulation of air quality and cost to ventilate swine farrowing facilities in winter

    PubMed Central

    Park, Jae Hong; Peters, Thomas M.; Altmaier, Ralph; Sawvel, Russell A.; Anthony, T. Renée

    2016-01-01

    We developed a simulation model to study the effect of ventilation airflow rate with and without filtered recirculation on airborne contaminant concentrations (dust, NH3, CO, and CO2) for swine farrowing facilities. Energy and mass balance equations were used to simulate the indoor air quality and operational cost for a variety of ventilation conditions over a 3-month winter period, using time-varied outdoor temperature. The sensitivity of input and output parameters on indoor air quality and operational cost were evaluated. Significant factors affecting model output included mean winter temperature, generation rate of contaminants, pit-air-exchange ratio, and recirculation ratio. As mean outdoor temperature was decreased from −2.5 °C to −12.5 °C, total operational costs were increased from $872 to $1304. Dust generation rate affected dust concentrations linearly. When dust generation rates changed −50% and +100% from baseline, indoor dust concentrations were changed −50% and +100%, respectively. The selection of a pit-air-exchange ratio was found critical to NH3 concentration, but has little impact on other contaminants or cost. As the pit-air-exchange ratio was increased from 0.1 to 0.3, the NH3 concentration was increased by a factor of 1.5. The recirculation ratio affected both IAQ factors and total operational cost. As the recirculation ratio decreased to 0, inhalable and respirable dust concentrations, humidity, NH3 and CO2 concentrations decreased and total operational cost ($2216) was 104% more than with pit-fan-only ventilation ($1088). When the recirculation ratio was 1, the total operational cost was increased by $573 (53%) compared to pit-fan-only. Simulation provides a useful tool for examining the costs and benefits to installing common ventilation technology to CAFO and, ultimately, making sound management decisions. PMID:26937062

  20. Simulation of air quality and cost to ventilate swine farrowing facilities in winter.

    PubMed

    Park, Jae Hong; Peters, Thomas M; Altmaier, Ralph; Sawvel, Russell A; Anthony, T Renée

    2013-10-01

    We developed a simulation model to study the effect of ventilation airflow rate with and without filtered recirculation on airborne contaminant concentrations (dust, NH3, CO, and CO2) for swine farrowing facilities. Energy and mass balance equations were used to simulate the indoor air quality and operational cost for a variety of ventilation conditions over a 3-month winter period, using time-varied outdoor temperature. The sensitivity of input and output parameters on indoor air quality and operational cost were evaluated. Significant factors affecting model output included mean winter temperature, generation rate of contaminants, pit-air-exchange ratio, and recirculation ratio. As mean outdoor temperature was decreased from -2.5 °C to -12.5 °C, total operational costs were increased from $872 to $1304. Dust generation rate affected dust concentrations linearly. When dust generation rates changed -50% and +100% from baseline, indoor dust concentrations were changed -50% and +100%, respectively. The selection of a pit-air-exchange ratio was found critical to NH3 concentration, but has little impact on other contaminants or cost. As the pit-air-exchange ratio was increased from 0.1 to 0.3, the NH3 concentration was increased by a factor of 1.5. The recirculation ratio affected both IAQ factors and total operational cost. As the recirculation ratio decreased to 0, inhalable and respirable dust concentrations, humidity, NH3 and CO2 concentrations decreased and total operational cost ($2216) was 104% more than with pit-fan-only ventilation ($1088). When the recirculation ratio was 1, the total operational cost was increased by $573 (53%) compared to pit-fan-only. Simulation provides a useful tool for examining the costs and benefits to installing common ventilation technology to CAFO and, ultimately, making sound management decisions.

  1. Transpired Solar Collector at NREL's Waste Handling Facility Uses Solar Energy to Heat Ventilation Air (Fact Sheet)

    SciTech Connect

    Not Available

    2010-09-01

    The transpired solar collector was installed on NREL's Waste handling Facility (WHF) in 1990 to preheat ventilation air. The electrically heated WHF was an ideal candidate for the this technology - requiring a ventilation rate of 3,000 cubic feet per meter to maintain safe indoor conditions.

  2. Software Configuration Management Plan for the B-Plant Canyon Ventilation Control System

    SciTech Connect

    MCDANIEL, K.S.

    1999-08-31

    Project W-059 installed a new B Plant Canyon Ventilation System. Monitoring and control of the system is implemented by the Canyon Ventilation Control System (CVCS). This Software Configuration Management Plan provides instructions for change control of the CVCS.

  3. HVAC SYSTEMS AS EMISSION SOURCES AFFECTING INDOOR AIR QUALITY: A CRITICAL REVIEW

    EPA Science Inventory

    The study evaluates heating, ventilating, and air-conditioning (HVAC) systems as contaminant emission sources that affect indoor air quality (IAQ). Various literature sources and methods for characterizing HVAC emission sources are reviewed. Available methods include in situ test...

  4. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...: (1) An integral vent system listed or certified as part of the appliance. (2) A venting system... roof line or outside the wall line may be installed at the site. Sectional venting systems shall...

  5. 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.

  6. Use of Recirculating Ventilation With Dust Filtration to Improve Wintertime Air Quality in a Swine Farrowing Room.

    PubMed

    Anthony, T Renée; Altmaier, Ralph; Jones, Samuel; Gassman, Rich; Park, Jae Hong; Peters, Thomas M

    2015-01-01

    The performance of a recirculating ventilation system with dust filtration was evaluated to determine its effectiveness to improve the air quality in a swine farrowing room of a concentrated animal feeding operation (CAFO). Air was exhausted from the room (0.47 m(3) sec(-1); 1000 cfm), treated with a filtration unit (Shaker-Dust Collector), and returned to the farrowing room to reduce dust concentrations while retaining heat necessary for livestock health. The air quality in the room was assessed over a winter, during which time limited fresh air is traditionally brought into the building. Over the study period, dust concentrations ranged from 0.005-0.31 mg m(-3) (respirable) and 0.17-2.09 mg m(-3) (inhalable). In-room dust concentrations were reduced (41% for respirable and 33% for inhalable) with the system in operation, while gas concentrations (ammonia [NH3], hydrogen sulfide [H2S], carbon monoxide [CO], carbon dioxide [CO2]) were unchanged. The position of the exhaust and return air systems provided reasonably uniform contaminant distributions, although the respirable dust concentrations nearest one of the exhaust ducts was statistically higher than other locations in the room, with differences averaging only 0.05 mg m(-3). Throughout the study, CO2 concentrations consistently exceeded 1540 ppm (industry recommendations) and on eight of the 18 study days it exceeded 2500 ppm (50% of the ACGIH TLV), with significantly higher concentrations near a door to a temperature-controlled hallway that was typically often left open. Alternative heaters are recommended to reduce CO2 concentrations in the room. Contaminant concentrations were modeled using production and environmental factors, with NH3 related to the number of sow in the room and outdoor temperatures and CO2 related to the number of piglets and outdoor temperatures. The recirculating ventilation system provided dust reduction without increasing concentrations of hazardous gases.

  7. Use of Recirculating Ventilation with Dust Filtration to Improve Wintertime Air Quality in a Swine Farrowing Room

    PubMed Central

    Anthony, T. Renée; Altmaier, Ralph; Jones, Samuel; Gassman, Rich; Park, Jae Hong; Peters, Thomas M.

    2016-01-01

    The performance of a recirculating ventilation system with dust filtration was evaluated to determine its effectiveness to improve the air quality in a swine farrowing room of a concentrated animal feeding operation (CAFO). Air was exhausted from the room (0.47 m3sec−1; 1000 cfm), treated with a filtration unit (Shaker-Dust Collector), and returned to the farrowing room to reduce dust concentrations while retaining heat necessary for livestock health. The air quality in the room was assessed over a winter, during which time limited fresh air is traditionally brought into the building. Over the study period, dust concentrations ranged from 0.005 to 0.31 mg m−3 (respirable) and 0.17 to 2.09 mg m−3 (inhalable). In-room dust concentrations were reduced (41% for respirable and 33% for inhalable) with the system in operation, while gas concentrations (ammonia [NH3], hydrogen sulfide [H2S], carbon monoxide [CO], carbon dioxide [CO2]) were unchanged. The position of the exhaust and return air systems provided reasonably uniform contaminant distributions, although the respirable dust concentrations nearest one of the exhaust ducts was statistically higher than other locations in the room, with differences averaging only 0.05 mg m−3. Throughout the study, CO2 concentrations consistently exceeded 1540 ppm (industry recommendations) and on eight of the 18 study days it exceeded 2500 ppm (50% of the ACGIH TLV), with significantly higher concentrations near a door to a temperature-controlled hallway that was typically often left open. Alternative heaters are recommended to reduce CO2 concentrations in the room. Contaminant concentrations were modeled using production and environmental factors, with NH3 related to the number of sow in the room and outdoor temperatures and CO2 related to the number of piglets and outdoor temperatures. The recirculating ventilation system provided dust reduction without increasing concentrations of hazardous gases. PMID:25950713

  8. Air ventilation impacts of the "wall effect" resulting from the alignment of high-rise buildings

    NASA Astrophysics Data System (ADS)

    Yim, S. H. L.; Fung, J. C. H.; Lau, A. K. H.; Kot, S. C.

    The objective of this study is to investigate the air ventilation impacts of the so called "wall effect" caused by the alignment of high-rise buildings in complex building clusters. The research method employs the numerical algorithm of computational fluid dynamics (CFD - FLUENT) to simulate the steady-state wind field in a typical Hong Kong urban setting and investigate pollutant dispersion inside the street canyon utilizing a pollutant transport model. The model settings of validation study were accomplished by comparing the simulation wind field around a single building block to wind tunnel data. The results revealed that our model simulation is fairly close to the wind tunnel measurements. In this paper, a typical dense building distribution in Hong Kong with 2 incident wind directions (0° and 22.5°) is studied. Two performance indicators are used to quantify the air ventilation impacts, namely the velocity ratio ( VR) and the retention time ( T r) of pollutants at the street level. The results indicated that the velocity ratio at 2 m above ground was reduced 40% and retention time of pollutants increased 80% inside the street canyon when high-rise buildings with 4 times height of the street canyon were aligned as a "wall" upstream. While this reduction of air ventilation was anticipated, the magnitude is significant and this result clearly has important implications for building and urban planning.

  9. Operational test report integrated system test (ventilation upgrade)

    SciTech Connect

    HARTY, W.M.

    1999-10-05

    Operational Final Test Report for Integrated Systems, Project W-030 (Phase 2 test, RECIRC and HIGH-HEAT Modes). Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks, including upgraded vapor space cooling and filtered venting of tanks AY101, Ay102, AZ101, AZ102.

  10. The Effectiveness of the Methane Drainage of Rock-Mass with a U Ventilation System

    NASA Astrophysics Data System (ADS)

    Szlązak, Nikodem; Swolkień, Justyna

    2016-09-01

    Methane drainage is used in Polish coal mines in order to reduce mine methane emission as well as to keep methane concentration in mine workings at safe levels. The article describes the method of methane drainage used in longwall D-2 in seam 410. In Poland, coal seams are frequently mined under difficult geological conditions in the roof and in the presence of very high methane hazard. In such situations, mines usually use a system with roof caving and a U ventilation system, which means that methane is drawn off from a tail entry behind the longwall front. In this system, boreholes are drilled from a tailgate and methane is drawn off from behind longwall face. The article shows the influence of a specific ventilation system on the drainage efficiency at longwall D-2 in seam 410. At this longwall, measurements of methane emission and the efficiency of methane capture were conducted. They consisted in gauging methane concentration, air velocity, absolute air pressure and the amount of methane captured by the drainage system. Experimental data were used to estimate the variations in absolute methane-bearing capacity and ventilation methane, and - most importantly - to gauge the efficiency of methane drainage.

  11. 6. VIEW LOOKING SOUTHEAST AT VENTILATION EQUIPMENT IN SOUTH VENTILATION ...

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

    6. VIEW LOOKING SOUTHEAST AT VENTILATION EQUIPMENT IN SOUTH VENTILATION HOUSE. THIS AIR CONDITIONING SYSTEM WAS INSTALLED BY PARKS-CRAMER COMPANY OF FITCHBURG, MASSACHUSETTS WHEN THE MILL WAS CONSTRUCTED IN 1923-24. ONE AIR WASHER AND FAN ROOM EXTERIOR IS VISIBLE ON THE RIGHT. THE DUCTS FROM BOTH FAN ROOMS (CURVED METAL STRUCTURES AT CENTER AND LEFT OF PHOTO) ARE CONNECTED TO A COMMON AIR SHAFT. - Stark Mill, 117 Corinth Road, Hogansville, Troup County, GA

  12. Dispersal of exhaled air and personal exposure in displacement ventilated rooms.

    PubMed

    Bjørn, E; Nielsen, P V

    2002-09-01

    The influence of the human exhalation on flow fields, contaminant distributions, and personal exposure in displacement ventilated rooms is studied together with the effects of physical movement. Experiments are conducted in full-scale test rooms with life-sized breathing thermal manikins. Numerical simulations support the experiments. Air exhaled through the mouth can lock in a thermally stratified layer, if the vertical temperature gradient in breathing zone height is sufficiently large. With exhalation through the nose, exhaled air flows to the upper part of the room. The exhalation flow from both nose and mouth is able to penetrate the breathing zone of another person standing nearby. The stratification of exhaled air breaks down if there is physical movement in the room. As movement increases, the concentration distribution in the room will move towards a fully mixed situation. The protective effect of the boundary layer flow around the body of a moving person disappears at low speed, and is reduced for a seated person placed nearby due to horizontal air movements, which can also cause rebreathing of exhaled air for the seated person. The results indicate that the effect of the exhalation flow is no acute problem in most normal ventilation applications. However, exhalation and local effects caused by movement may be worth considering if one wishes to contain contaminants in certain areas, as in the case of tobacco smoking, in hospitals and clinics, or in certain industries.

  13. Evaluation of the indoor air quality minimum ventilation rate procedure for use in California retail buildings.

    PubMed

    Dutton, S M; Mendell, M J; Chan, W R; Barrios, M; Sidheswaran, M A; Sullivan, D P; Eliseeva, E A; Fisk, W J

    2015-02-01

    This research assesses benefits of adding to California Title-24 ventilation rate (VR) standards a performance-based option, similar to the American Society of Heating, Refrigerating, and Air Conditioning Engineers 'Indoor Air Quality Procedure' (IAQP) for retail spaces. Ventilation rates and concentrations of contaminants of concern (CoC) were measured in 13 stores. Mass balance models were used to estimate 'IAQP-based' VRs that would maintain concentrations of all CoCs below health- or odor-based reference concentration limits. An intervention study in a 'big box' store assessed how the current VR, the Title 24-prescribed VR, and the IAQP-based VR (0.24, 0.69, and 1.51 air changes per hour) influenced measured IAQ and perceived of IAQ. Neither current VRs nor Title 24-prescribed VRs would maintain all CoCs below reference limits in 12 of 13 stores. In the big box store, the IAQP-based VR kept all CoCs below limits. More than 80% of subjects reported acceptable air quality at all three VRs. In 11 of 13 buildings, saving energy through lower VRs while maintaining acceptable IAQ would require source reduction or gas-phase air cleaning for CoCs. In only one of the 13 retail stores surveyed, application of the IAQP would have allowed reduced VRs without additional contaminant-reduction strategies.

  14. Direct Digital Control of HVAC (Heating, Ventilating, and Air Conditioning).

    DTIC Science & Technology

    1985-01-01

    many feet downstream from the damper. For most HVAC applications, PI control is an adequate control technique. A more detailed description of PID control...consumption of two HVAC Systems with PI Control . (Ref 2) 26 Conventional Built-up Control D lirect Digital System complexity F igure 14. Relationships between

  15. Risk Assessment of Heating, Ventilating, and Air-Conditioning Strategies in Low-Load Homes

    SciTech Connect

    Poerschke, Andrew

    2016-02-17

    "Modern, energy efficient homes conforming to the Zero Energy Ready Home standard face the challenge of meeting high customer expectations for comfort. Traditional heating, ventilation, and air conditioning (HVAC) sizing and control strategies may be insufficient to adequately condition each zone due to unique load patterns in each room caused by a number of factors. These factors include solar heat gains, occupant-related gains, and gains associated with appliances and electronics. Because of shrinking shell loads, these intermittent factors are having an increasingly significant impact on the thermal load in each zone. Consequently, occupant comfort can be compromised. To evaluate the impact of climate and house geometry, as well as HVAC system and control strategies on comfort conditions, IBACOS analyzed the results of 99 TRNSYS multiple-zone simulations. The results of this analysis indicate that for simple-geometry and single-story plans, a single zone and thermostat can adequately condition the entire house. Demanding house geometry and houses with multiple stories require the consideration of multiple thermostats and multiple zones.

  16. The role of exhaust ventilation systems in reducing occupational exposure to organic solvents in a paint manufacturing factory

    PubMed Central

    Jafari, Mohammad Javad; Karimi, Ali; Azari, Mansoor Rezazadeh

    2008-01-01

    This paper presents the successful design and implementation of several exhaust ventilation systems in a paint manufacturing factory. The ventilation systems were designed based on American Conference of Governmental Industrial Hygienists recommendations. The duct works, fans, and other parts were made and mounted by local manufacturers. The concentrations of toluene and xylene as the common solvents used in paint mixing factories were measured to evaluate the role of ventilation systems in controlling the organic solvents. Occupational exposure to toluene and xylene as the major pollutants was assessed with and without applying ventilation systems. For this purpose, samples were taken from breathing zone of exposed workers using personal samples. The samples were analyzed using Occupational Safety and Health Administration analytical method No.12. The samples were quantified using gas chromatography. The results showed that the ventilation systems successfully controlled toluene and xylene vapors in workplace, air well below the recommended threshold limit value of Iran (44.49 and 97.73 ppm, respectively). It was also discovered that benzene concentration in workplace air was higher than its allowable concentrations. This could be from solvents impurities that require more investigations. PMID:20040984

  17. Aerodynamic Characteristics of the Ventilated Design for Flapping Wing Micro Air Vehicle

    PubMed Central

    Zhang, G. Q.; Yu, S. C. M.

    2014-01-01

    Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the “ventilation” in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds. PMID:24683339

  18. VWPS: A Ventilator Weaning Prediction System with Artificial Intelligence

    NASA Astrophysics Data System (ADS)

    Chen, Austin H.; Chen, Guan-Ting

    How to wean patients efficiently off mechanical ventilation continues to be a challenge for medical professionals. In this paper we have described a novel approach to the study of a ventilator weaning prediction system (VWPS). Firstly, we have developed and written three Artificial Neural Network (ANN) algorithms to predict a weaning successful rate based on the clinical data. Secondly, we have implemented two user-friendly weaning success rate prediction systems; the VWPS system and the BWAP system. Both systems could be used to help doctors objectively and effectively predict whether weaning is appropriate for patients based on the patients' clinical data. Our system utilizes the powerful processing abilities of MatLab. Thirdly, we have calculated the performance through measures such as sensitivity and accuracy for these three algorithms. The results show a very high sensitivity (around 80%) and accuracy (around 70%). To our knowledge, this is the first design approach of its kind to be used in the study of ventilator weaning success rate prediction.

  19. Laboratory Ventilation and Safety.

    ERIC Educational Resources Information Center

    Steere, Norman V.

    1965-01-01

    In order to meet the needs of both safety and economy, laboratory ventilation systems must effectively remove air-borne toxic and flammable materials and at the same time exhaust a minimum volume of air. Laboratory hoods are the most commonly used means of removing gases, dusts, mists, vapors, and fumed from laboratory operations. To be effective,…

  20. 30 CFR 75.324 - Intentional changes in the ventilation system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Intentional changes in the ventilation system... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.324 Intentional changes in the ventilation system. (a) A person designated by the operator shall supervise...

  1. 30 CFR 75.324 - Intentional changes in the ventilation system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Intentional changes in the ventilation system... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.324 Intentional changes in the ventilation system. (a) A person designated by the operator shall supervise...

  2. 30 CFR 75.324 - Intentional changes in the ventilation system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Intentional changes in the ventilation system... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.324 Intentional changes in the ventilation system. (a) A person designated by the operator shall supervise...

  3. 30 CFR 75.324 - Intentional changes in the ventilation system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Intentional changes in the ventilation system... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.324 Intentional changes in the ventilation system. (a) A person designated by the operator shall supervise...

  4. 30 CFR 75.324 - Intentional changes in the ventilation system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Intentional changes in the ventilation system... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.324 Intentional changes in the ventilation system. (a) A person designated by the operator shall supervise...

  5. ASSESSMENT of POTENTIAL CARBON DIOXIDE-BASED DEMAND CONTROL VENTILATION SYSTEM PERFORMANCE in SINGLE ZONE SYSTEMS

    DTIC Science & Technology

    2013-03-21

    occupancy, per American Society of Heating, Refrigeration, and Air Conditioning Engineers ( ASHRAE ) standards. This research aims to create a...38  Figure 15. Thermal Comfort Range ( ASHRAE , 2010a) ................................................. 46  Figure 16. Airflows to be Considered...Distribution Effectiveness ( ASHRAE 2010b) .... 51  Table 12. Baseline Outside Ventilation Air Flow

  6. Air cushion landing system

    NASA Technical Reports Server (NTRS)

    Boghami, K. M.; Captain, K. M.; Fish, R. B.

    1978-01-01

    Static and dynamic performance of air cushion landing system is simulated in computer program that treats four primary ACLS subsystems: fan, feeding system, trunk, and cushion. Configuration of systems is sufficiently general to represent variety of practical designs.

  7. Field measurement of ventilation rates.

    PubMed

    Persily, A K

    2016-02-01

    Ventilation rates have significant impacts on building energy use and indoor contaminant concentrations, making them key parameters in building performance. Ventilation rates have been measured in buildings for many decades, and there are mature measurement approaches available to researchers and others who need to know actual ventilation rates in buildings. Despite the fact that ventilation rates are critical in interpreting indoor concentration measurements, it is disconcerting how few Indoor Air Quality field studies measure ventilation rates or otherwise characterize the ventilation design of the study building(s). This paper summarizes parameters of interest in characterizing building ventilation, available methods for quantifying these parameters, and challenges in applying these methods to different types of buildings and ventilation systems. These parameters include whole-building air change rates, system outdoor air intake rates, and building infiltration rates. Tracer gas methods are reviewed as well as system airflow rate measurements using, for example, duct traverses. Several field studies of ventilation rates conducted over the past 75 years are described to highlight the approaches employed and the findings obtained.

  8. Numerical simulation of volume-controlled mechanical ventilated respiratory system with 2 different lungs.

    PubMed

    Shi, Yan; Zhang, Bolun; Cai, Maolin; Zhang, Xiaohua Douglas

    2016-11-09

    Mechanical ventilation is a key therapy for patients who cannot breathe adequately by themselves, and dynamics of mechanical ventilation system is of great significance for life support of patients. Recently, models of mechanical ventilated respiratory system with 1 lung are used to simulate the respiratory system of patients. However, humans have 2 lungs. When the respiratory characteristics of 2 lungs are different, a single-lung model cannot reflect real respiratory system. In this paper, to illustrate dynamic characteristics of mechanical ventilated respiratory system with 2 different lungs, we propose a mathematical model of mechanical ventilated respiratory system with 2 different lungs and conduct experiments to verify the model. Furthermore, we study the dynamics of mechanical ventilated respiratory system with 2 different lungs. This research study can be used for improving the efficiency and safety of volume-controlled mechanical ventilation system.

  9. Evaluation of thermal formation and air ventilation inside footwear during gait: The role of gait and fitting.

    PubMed

    Shimazaki, Yasuhiro; Matsutani, Toshiki; Satsumoto, Yayoi

    2016-07-01

    Comfort is an important concept in footwear design. The microclimate inside footwear contributes to the perception of thermal comfort. To investigate the effect of ventilation on microclimate formation inside footwear, experiments with subjects were conducted at four gait speeds with three different footwear sizes. Skin temperature, metabolism, and body mass were measured at approximately 25 °C and 50% relative humidity, with no solar radiation and a calm wind. The footwear occupancy and ventilation rate were also estimated, with the latter determined using the tracer gas method. The experimental results revealed that foot movement, metabolism, evaporation, radiation, convection, and ventilation were the main factors influencing the energy balance for temperature formation on the surface of the foot. The cooling effect of ventilation on the arch temperature was observed during gait. The significance of the amount of air space and ventilation on the improvement in the thermal comfort of footwear was clarified.

  10. Ventilation flow: Submerged

    NASA Technical Reports Server (NTRS)

    Hutchinson, D.

    1985-01-01

    The ventilation system on a submarine is discussed. When the submarine is submerged. The ventilation system provides a conditioned atmosphere in the ship with complete isolation from the outside. A conditioned atmosphere includes not only filtration and temperature and humidity control, but also air purification (removal of potentially harmful quantities of impurities and comtaminants) and revitalization (addition of vital life support oxygen). Carbon dioxide removal, the oxygen system, air conditioning, carbon monoxide removal, hydrogen removal, and atmosphere monitoring systems are among the topics discussed.

  11. Quantifying the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building.

    PubMed

    Tong, Zheming; Chen, Yujiao; Malkawi, Ali; Adamkiewicz, Gary; Spengler, John D

    2016-01-01

    Improper natural ventilation practices may deteriorate indoor air quality when in close proximity to roadways, although the intention is often to reduce energy consumption. In this study, we employed a CFD-based air quality model to quantify the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building. Our study found that the building envelope restricts dispersion and dilution of particulate matter. The indoor concentration in the baseline condition located 10m away from the roadway is roughly 16-21% greater than that at the edge of the roadway. The indoor flow recirculation creates a well-mixed zone with little variation in fine particle concentration (i.e., 253nm). For ultrafine particles (<100nm), a noticeable decrease in particle concentrations indoors with increasing distance from the road is observed due to Brownian and turbulent diffusion. In addition, the indoor concentration strongly depends on the distance between the roadway and building, particle size, wind condition, and window size and location. A break-even point is observed at D'~2.1 (normalized distance from the roadway by the width of the road). The indoor particle concentration is greater than that at the highway where D'<2.1, and vice versa. For new building planning, the distance from the roadway and the ambient wind condition need to be considered at the early design stage whereas the size and location of the window openings, the interior layout, and the placement of fresh air intakes are important to the indoor air quality of existing buildings adjacent to roadways.

  12. [Post traumatic air tamponade under assisted ventilation. Case report from Dakar, Senegal].

    PubMed

    Kenane, N; Montcriol, A; Bordes, J; Prunet, B; Ledantec, P; N'diaye, M

    2009-02-01

    Compressive pnemopericardium is an uncommon cause of shock after blunt trauma. The purpose of this report is to describe a case of air tamponnade observed during management of a patient with thoraco-abominal injuries in Dakar, Senegal. Diagnosis was suspected based on chest x-rays and subsequently confirmed by CT-scan. Clinical features included shock syndrome, small heart sign, and constant deterioration under assisted ventilation. Despite initial improvement after needle aspiration, the patient died due to probable recurrence of air tamponnade. Based on their review of the literature, the authors discuss the physiopathology of air tamponande and emergency treatment by needle aspiration that must be followed by surgery for creation of a pericardial window.

  13. Double Shell Tank (DST) Ventilation System Vapor Sampling and Analysis Plan

    SciTech Connect

    SASAKI, L.M.

    2000-06-08

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples from the primary ventilation systems of the AN, AP, AW, and AY/AZ tank farms. Sampling will be performed in accordance with Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis (Air DQO) (Mulkey 1999). The sampling will verify if current air emission estimates used in the permit application are correct and provide information for future air permit applications. Vapor samples will be obtained from tank farm ventilation systems, downstream from the tanks and upstream of any filtration. Samples taken in support of the DQO will consist of SUMMA{trademark} canisters, triple sorbent traps (TSTs), sorbent tube trains (STTs), polyurethane foam (PUF) samples. Particulate filter samples and tritium traps will be taken for radiation screening to allow the release of the samples for analysis. The following sections provide the general methodology and procedures to be used in the preparation, retrieval, transport, analysis, and reporting of results from the vapor samples.

  14. Chemical method of checking the airtightness of ventilation systems and containment structures of buildings (with the use of Congo red)

    SciTech Connect

    Kuz'micheva, T.N.; Mazurenok, A.M.; Eliseev, V.P.; Naidenov, A.Ya.; Budarin, L.I.; Zhuchenko, E.P.

    1988-11-01

    The problem of using the chemical method for checking the airtightness of ventilation systems and containment structures with the use of indicator materials on a base of Congo red and an air-ammonia mixture as the test medium was examined. The methods and results of experimental investigations of leaks characteristic for containment structures and ventilation systems are given. Suggestions are given on a determination of the parameters of local leaks and on the practical use of the given method for evaluating the quality of sealing.

  15. Ventilation Model Report

    SciTech Connect

    V. Chipman; J. Case

    2002-12-20

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. Revision 01 ICN 01 included the results of the unqualified software code MULTIFLUX to assess the influence of moisture on the ventilation efficiency. The purposes of Revision 02 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of

  16. Analysis of radon reduction and ventilation systems in uranium mines in China.

    PubMed

    Hu, Peng-hua; Li, Xian-jie

    2012-09-01

    Mine ventilation is the most important way of reducing radon in uranium mines. At present, the radon and radon progeny levels in Chinese uranium mines where the cut and fill stoping method is used are 3-5 times higher than those in foreign uranium mines, as there is not much difference in the investments for ventilation protection between Chinese uranium mines and international advanced uranium mines with compaction methodology. In this paper, through the analysis of radon reduction and ventilation systems in Chinese uranium mines and the comparison of advantages and disadvantages between a variety of ventilation systems in terms of radon control, the authors try to illustrate the reasons for the higher radon and radon progeny levels in Chinese uranium mines and put forward some problems in three areas, namely the theory of radon control and ventilation systems, radon reduction ventilation measures and ventilation management. For these problems, this paper puts forward some proposals regarding some aspects, such as strengthening scrutiny, verifying and monitoring the practical situation, making clear ventilation plans, strictly following the mining sequence, promoting training of ventilation staff, enhancing ventilation system management, developing radon reduction ventilation technology, purchasing ventilation equipment as soon as possible in the future, and so on.

  17. 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.

  18. DEMAND CONTROLLED VENTILATION AND CLASSROOM VENTILATION

    SciTech Connect

    Fisk, William J.; Mendell, Mark J.; Davies, Molly; Eliseeva, Ekaterina; Faulkner, David; Hong, Tienzen; Sullivan, Douglas P.

    2014-01-06

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling. Major findings included: ? The single-location carbon dioxide sensors widely used for demand controlled ventilation frequently have large errors and will fail to effectively control ventilation rates (VRs).? Multi-location carbon dioxide measurement systems with more expensive sensors connected to multi-location sampling systems may measure carbon dioxide more accurately.? Currently-available optical people counting systems work well much of the time but have large counting errors in some situations. ? In meeting rooms, measurements of carbon dioxide at return-air grilles appear to be a better choice than wall-mounted sensors.? In California, demand controlled ventilation in general office spaces is projected to save significant energy and be cost effective only if typical VRs without demand controlled ventilation are very high relative to VRs in codes. Based on the research, several recommendations were developed for demand controlled ventilation specifications in the California Title 24 Building Energy Efficiency Standards.The research on classroom ventilation collected data over two years on California elementary school classrooms to investigate associations between VRs and student illness absence (IA). Major findings included: ? Median classroom VRs in all studied climate zones were below the California guideline, and 40percent lower in portable than permanent buildings.? Overall, one additional L/s per person of VR was associated with 1.6percent less IA. ? Increasing average VRs in California K-12 classrooms from the current average to the required level is estimated to decrease IA by 3.4percent, increasing State attendance-based funding to school districts by $33M, with $6.2 M in increased energy costs. Further VR increases would provide additional benefits

  19. An air flow sensor for neonatal mechanical ventilation applications based on a novel fiber-optic sensing technique

    NASA Astrophysics Data System (ADS)

    Battista, L.; Sciuto, S. A.; Scorza, A.

    2013-03-01

    In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sensitive to light intensity fluctuation independent by measurand than intensity-based sensors. The considered technique is here adopted in order to develop two different configurations for an air flow sensor suitable for the measurement of air flow rates typically occurring during mechanical ventilation of newborns: a mono-directional and a bi-directional transducer have been proposed. A mathematical model for the air flow sensor is here proposed and a static calibration of two different arrangements has been performed: a measurement range up to 3.00 × 10-4 m3/s (18.0 l/min) for the mono-directional sensor and a measurement range of ±3.00 × 10-4 m3/s (±18.0 l/min) for the bi-directional sensor are experimentally evaluated, according to the air flow rates normally encountered during tidal breathing of infants with a mass lower than 10 kg. Experimental data of static calibration result in accordance with the proposed theoretical model: for the mono-directional configuration, the

  20. Effects of animal activity and air temperature on methane and ammonia emissions from a naturally ventilated building for dairy cows

    NASA Astrophysics Data System (ADS)

    Ngwabie, N. M.; Jeppsson, K.-H.; Gustafsson, G.; Nimmermark, S.

    2011-12-01

    Knowledge of how different factors affect gas emissions from animal buildings can be useful for emission prediction purposes and for the improvement of emission abatement techniques. In this study, the effects of dairy cow activity and indoor air temperature on gas emissions were examined. The concentrations of CH 4, NH 3, CO 2 and N 2O inside and outside a dairy cow building were measured continuously between February and May together with animal activity and air temperature. The building was naturally ventilated and had a solid concrete floor which sloped towards a central urine gutter. Manure was scraped from the floor once every hour in the daytime and once every second hour at night into a partly covered indoor pit which was emptied daily at 6 a.m. and at 5 p.m. Gas emissions were calculated from the measured gas concentrations and ventilation rates estimated by the CO 2 balance method. The animal activity and emission rates of CH 4 and NH 3 showed significant diurnal variations with two peaks which were probably related to the feeding routine. On an average day, CH 4 emissions ranged from 7 to 15 g LU -1 h -1 and NH 3 emissions ranged from 0.4 to 1.5 g LU -1 h -1 (1 LU = 500 kg animal weight). Mean emissions of CH 4 and NH 3 were 10.8 g LU -1 h -1 and 0.81 g LU -1 h -1, respectively. The NH 3 emissions were comparable to emissions from tied stall buildings and represented a 4% loss in manure nitrogen. At moderate levels, temperature seems to affect the behaviour of dairy cows and in this study where the daily indoor air temperature ranged from about 5 up to about 20 °C, the daily activity of the cows decreased with increasing indoor air temperature ( r = -0.78). Results suggest that enteric fermentation is the main source of CH 4 emissions from systems of the type in this study, while NH 3 is mainly emitted from the manure. Daily CH 4 emissions increased significantly with the activity of the cows ( r = 0.61) while daily NH 3 emissions increased

  1. An air flow sensor for neonatal mechanical ventilation applications based on a novel fiber-optic sensing technique

    SciTech Connect

    Battista, L.; Sciuto, S. A.; Scorza, A.

    2013-03-15

    In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sensitive to light intensity fluctuation independent by measurand than intensity-based sensors. The considered technique is here adopted in order to develop two different configurations for an air flow sensor suitable for the measurement of air flow rates typically occurring during mechanical ventilation of newborns: a mono-directional and a bi-directional transducer have been proposed. A mathematical model for the air flow sensor is here proposed and a static calibration of two different arrangements has been performed: a measurement range up to 3.00 Multiplication-Sign 10{sup -4} m{sup 3}/s (18.0 l/min) for the mono-directional sensor and a measurement range of {+-}3.00 Multiplication-Sign 10{sup -4} m{sup 3}/s ({+-}18.0 l/min) for the bi-directional sensor are experimentally evaluated, according to the air flow rates normally encountered during tidal breathing of infants with a mass lower than 10 kg. Experimental data of static calibration result in accordance with the proposed

  2. An air flow sensor for neonatal mechanical ventilation applications based on a novel fiber-optic sensing technique.

    PubMed

    Battista, L; Sciuto, S A; Scorza, A

    2013-03-01

    In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sensitive to light intensity fluctuation independent by measurand than intensity-based sensors. The considered technique is here adopted in order to develop two different configurations for an air flow sensor suitable for the measurement of air flow rates typically occurring during mechanical ventilation of newborns: a mono-directional and a bi-directional transducer have been proposed. A mathematical model for the air flow sensor is here proposed and a static calibration of two different arrangements has been performed: a measurement range up to 3.00 × 10(-4) m(3)∕s (18.0 l∕min) for the mono-directional sensor and a measurement range of ±3.00 × 10(-4) m(3)∕s (±18.0 l∕min) for the bi-directional sensor are experimentally evaluated, according to the air flow rates normally encountered during tidal breathing of infants with a mass lower than 10 kg. Experimental data of static calibration result in accordance with the proposed theoretical model: for the mono

  3. Descriptions and diagrams of the primary and annulus ventilation systems of the double-shell tank farms as of January 1988

    SciTech Connect

    Blackman, A.E.; Waters, E.D.

    1994-12-28

    This document is a compilation of information describing the ventilation systems of the Double-Shell Tank farms (214-AN, -AP, -AW, -AW, -AY, -AZ, and -SY). A general description of the primary tank and annulus ventilation systems is given along with specific information on the high efficiency particulate air (HEPA) filters, condensers, preheaters, exhaust fans, and piping. This information is considered to be current as of January 1988. 38 refs, 20 figs, 30 tabs.

  4. Summary of human responses to ventilation

    SciTech Connect

    Seppanen, Olli A.; Fisk, William J.

    2004-06-01

    The effects of ventilation on indoor air quality and health is a complex issue. It is known that ventilation is necessary to remove indoor generated pollutants from indoor air or dilute their concentration to acceptable levels. But, as the limit values of all pollutants are not known, the exact determination of required ventilation rates based on pollutant concentrations and associated risks is seldom possible. The selection of ventilation rates has to be based also on epidemiological research (e.g. Seppanen et al., 1999), laboratory and field experiments (e.g. CEN 1996, Wargocki et al., 2002a) and experience (e.g. ECA 2003). Ventilation may also have harmful effects on indoor air quality and climate if not properly designed, installed, maintained and operated as summarized by Seppdnen (2003). Ventilation may bring indoors harmful substances that deteriorate the indoor environment. Ventilation also affects air and moisture flow through the building envelope and may lead to moisture problems that deteriorate the structures of the building. Ventilation changes the pressure differences over the structures of building and may cause or prevent the infiltration of pollutants from structures or adjacent spaces. Ventilation is also in many cases used to control the thermal environment or humidity in buildings. Ventilation can be implemented with various methods which may also affect health (e.g. Seppdnen and Fisk, 2002, Wargocki et al., 2002a). In non residential buildings and hot climates, ventilation is often integrated with air-conditioning which makes the operation of ventilation system more complex. As ventilation is used for many purposes its health effects are also various and complex. This paper summarizes the current knowledge on positive and negative effects of ventilation on health and other human responses. The focus of the paper is on office-type working environment and residential buildings. In the industrial premises the problems of air quality are usually

  5. Modeling exposure close to air pollution sources in naturally ventilated residences: association of turbulent diffusion coefficient with air change rate.

    PubMed

    Cheng, Kai-Chung; Acevedo-Bolton, Viviana; Jiang, Ruo-Ting; Klepeis, Neil E; Ott, Wayne R; Fringer, Oliver B; Hildemann, Lynn M

    2011-05-01

    For modeling exposure close to an indoor air pollution source, an isotropic turbulent diffusion coefficient is used to represent the average spread of emissions. However, its magnitude indoors has been difficult to assess experimentally due to limitations in the number of monitors available. We used 30-37 real-time monitors to simultaneously measure CO at different angles and distances from a continuous indoor point source. For 11 experiments involving two houses, with natural ventilation conditions ranging from <0.2 to >5 air changes per h, an eddy diffusion model was used to estimate the turbulent diffusion coefficients, which ranged from 0.001 to 0.013 m² s⁻¹. The model reproduced observed concentrations with reasonable accuracy over radial distances of 0.25-5.0 m. The air change rate, as measured using a SF₆ tracer gas release, showed a significant positive linear correlation with the air mixing rate, defined as the turbulent diffusion coefficient divided by a squared length scale representing the room size. The ability to estimate the indoor turbulent diffusion coefficient using two readily measurable parameters (air change rate and room dimensions) is useful for accurately modeling exposures in close proximity to an indoor pollution source.

  6. Rooftop Unitary Air Conditioner with Integral Dedicated Outdoor Air System

    SciTech Connect

    Tiax Llc

    2006-02-28

    Energy use of rooftop and other unitary air-conditioners in commercial applications accounts for about 1 quad (10{sup 15} Btu) of primary energy use annually in the U.S. [Reference 7]. The realization that this cooling equipment accounts for the majority of commercial building cooled floorspace and the majority also of commercial building energy use has spurred development of improved-efficiency equipment as well as development of stricter standards addressing efficiency levels. Another key market driver affecting design of rooftop air-conditioning equipment has been concern regarding comfort and the control of humidity. Trends for increases in outdoor air ventilation rates in certain applications, and the increasing concern about indoor air quality problems associated with humidity levels and moisture in buildings points to a need for improved dehumidification capability in air-conditioning equipment of all types. In many cases addressing this issue exacerbates energy efficiency, and vice versa. The integrated dedicated outdoor air system configuration developed in this project addresses both energy and comfort/humidity issues.

  7. Observations of the Valley of Mexico Basin Ventilation Through the Tenango del Aire- Amecameca Geographical Gap

    NASA Astrophysics Data System (ADS)

    Ruiz-Suarez, G.; Torres-Jarón, R.; Steinbrecher, R.; Junkermann, W.; Torres-Jaramillo, A.; Garcia, A. R.; Mar-Morales, B.

    2007-05-01

    Past air quality modeling exercises have suggested the existence of basin drainage flows which may transport Mexico City Metropolitan Area's air pollution plume outside the Valley of Mexico Basin. The MCMA-2006 field campaign offered the opportunity to study the basin ventilation through a geographical gap in the southeast mountains of the basin. A mobile monitoring lab was placed at the Tenango del Aire town, a unique site located in this gap for measuring the pass of air masses from (and towards) the MCMA to (and from) the Cuautla Valley. O3, CO, NOx, NOy, CH2O global and UV radiation and MLH were measured continuously during MILAGRO from March 2 until April 6, together with other chemical species. Complementary backward and forward trajectories were constructed for the site using MCCM in prognostic mode during MILAGRO. An exploratory analysis of the air pollution roses measured at Tenango showed a sharp dominance of two flow patterns: one from the north well associated with relatively higher levels of primary pollutants and ozone levels; and another one from the south typically associated with lower levels primary pollutants but not so low of secondary ones as ozone. On the other hand, measured CO data at Tenango were compared with CO data measured at one local monitoring station in the town of Ocuituco in the State of Morelos. Ocuituco is located to the south of Tenango towards the Cuautla Valley. The preliminary results suggest that the back and forth pass of air masses through the Tenango del Aire - Amecameca area can be an important process in the regional transport of air pollution between two valleys and their metropolitan areas within the Central Mexico region.

  8. Usability Heuristics and Qualitative Indicators for the Usability Evaluation of Touch Screen Ventilator Systems

    NASA Astrophysics Data System (ADS)

    Katre, Dinesh; Bhutkar, Ganesh; Karmarkar, Shekhar

    A ventilator system provides respiratory support to critically ill patients in the Intensive Care Unit. Increasing complexity in the user interface, features and functionalities of ventilator systems can cause medical errors and cost the life of a patient. Therefore, the usability of ventilator systems is most crucial to ensure patient safety. We have evolved a specialized set of heuristics combined with objectively defined usability indicators for the usability evaluation of touch screen based ventilator systems. Our study presents the heuristic evaluation of three touch screen based ventilator systems manufactured by three different companies. The heuristic evaluation has been performed by four different usability evaluators to ensure the reliability of heuristics proposed in this paper. The specialized set of heuristics linked with user interface components and the objectively defined usability indicators are found more reliable in identifying specific usability problems of ventilator systems.

  9. HVAC system performance and indoor air quality

    SciTech Connect

    Newman, J.L. )

    1991-01-01

    This paper reports that in the mid-seventies, the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) promulgated ASHRAE Standard 90-75 Energy Conservation in New Building Design, which called for revised minimum ventilation rates and the elimination of energy-wasting HVAC systems. Most building codes which cover energy conservation in the late seventies and eighties referred to this standard. This lowering of ventilation rates, coupled with the tighter building envelope (walls, windows, doors and roof) led to a reduction in outside air, both by engineering design and by minimizing infiltration through the structure. The minimum ventilation rates are based on the assumption that average concentrations of tobacco smoke exist in all enclosed spaces (30 percent of the population being smokers at two cigarettes per hour), rather than having separate rates for smoking and nonsmoking areas, as in the 1981 revision of the Standard. If tobacco smoke is ever declared a carcinogen, it will undoubtedly prompt a review of Standard 62-1989, as well as hasten totally smoke-free buildings.

  10. Ventilators for noninvasive ventilation to treat acute respiratory failure.

    PubMed

    Scala, Raffaele; Naldi, Mario

    2008-08-01

    The application of noninvasive ventilation (NIV) to treat acute respiratory failure has increased tremendously both inside and outside the intensive care unit. The choice of ventilator is crucial for success of NIV in the acute setting, because poor tolerance and excessive air leaks are significantly correlated with NIV failure. Patient-ventilator asynchrony and discomfort can occur if the physician or respiratory therapist fails to adequately set NIV to respond to the patient's ventilatory demand, so clinicians need to fully understood the ventilator's technical peculiarities (eg, efficiency of trigger and cycle systems, speed of pressurization, air-leak compensation, CO(2) rebreathing, reliability of fraction of inspired oxygen reading, monitoring accuracy). A wide range of ventilators of different complexity have been introduced into clinical practice to noninvasively support patients in acute respiratory failure, but the numerous commercially available ventilators (bi-level, intermediate, and intensive care unit ventilators) have substantial differences that can influence patient comfort, patient-ventilator interaction, and, thus, the chance of NIV clinical success. This report examines the most relevant aspects of the historical evolution, the equipment, and the acute-respiratory-failure clinical application of NIV ventilators.

  11. Measurement of HVAC system performance and local ventilation using passive perfluorocarbon tracer technology

    SciTech Connect

    Dietz, R.N.; Goodrich, R.W.

    1995-06-01

    In April of 1993, two (2) perfluorocarbon tracer (PFT) ventilation/indoor air quality assessment tests were performed in the Gleeson Hall building of the SUNY Farmingdale campus. The building was being modified, in part, as a result of significant occupant complaints of perceived poor air quality. The four story building had a basement first floor with air supplied normally by an HVAC system labelled as AC1. During this study, AC1 was inoperational and the basement interior rooms (walls) were primarily gone; the other three floors were still being used for classes. It is possible that a sense of poor air quality may have been perceived by first-floor occupants because they were working in the basement, but this issue could not be addressed. The second floor had two (2) lecture halls--Rm 202 (handled by AC4) and Rm 204 (handled by AC5); the balance of the second floor interior rooms and corridors was split between two other air handling systems, AC2 for the west side of the building and AC3 for the east side. The remaining 3rd and 4th floors were also split about evenly between AC2 and AC3. The perimeter rooms, equipped with wall units having their own outside air (OA) source plus centralized return air (RA) bypasses, were not included in this testing which was restricted to the basement floor (1st floor) and the four operating air handling systems, AC2 to AC5, during Test 1 and only AC2 to AC5 during Test 2. Two types of tests were performed using the full suite of 5 PFT types available. The first test was designed to measure the infiltration, exfiltration, and air exchange between the 5 AC zones above and the second test used the 5th tracer, which had been in the basement, as a distributed source throughout the four other zones to act as a surrogate pollutant source. This report provides final conclusions of both tests and suggestions regarding its usefulness in similar building ventilation and indoor air quality assessments.

  12. Reducing Mortality from Terrorist Releases of Chemical and Biological Agents: I. Filtration for Ventilation Systems in Commercial Building

    SciTech Connect

    Thatcher, Tracy L.; Daisey, Joan M.

    1999-09-01

    There is growing concern about potential terrorist attacks involving releases of chemical and/or biological (CB) agents, such as sarin or anthrax, in and around buildings. For an external release, the CB agent can enter the building through the air intakes of a building's mechanical ventilation system and by infiltration through the building envelope. For an interior release in a single room, the mechanical ventilation system, which often recirculates some fraction of the air within a building, may distribute the released CB agent throughout the building. For both cases, installing building systems that remove chemical and biological agents may be the most effective way to protect building occupants. Filtration systems installed in the heating, ventilating and air-conditioning (HVAC) systems of buildings can significantly reduce exposures of building occupants in the event of a release, whether the release is outdoors or indoors. Reduced exposures can reduce the number of deaths from a terrorist attack. The purpose of this report is to provide information and examples of the design of filtration systems to help building engineers retrofit HVAC systems. The report also provides background information on the physical nature of CB agents and brief overviews of the basic principles of particle and vapor filtration.

  13. Culture systems: air quality.

    PubMed

    Thomas, Theodore

    2012-01-01

    Poor laboratory air quality is a known hazard to the culture of human gametes and embryos. Embryologists and chemists have employed analytical methods for identifying and measuring bulk and select air pollutants to assess the risk they pose to the embryo culture system. However, contaminant concentrations that result in gamete or embryotoxicity are poorly defined. Combating the ill effects of poor air quality requires an understanding of how toxicants can infiltrate the laboratory, the incubator, and ultimately the culture media. A further understanding of site-specific air quality can then lead to the consideration of laboratory design and management strategies that can minimize the deleterious effects that air contamination may have on early embryonic development in vitro.

  14. Airborne Effluent Monitoring System Certification for New Canister Storage Building Ventilation Exhaust Stack

    SciTech Connect

    Glissmeyer, J.A.; Maughan, A.D.

    1999-04-01

    Pacific Northwest National Laboratory conducted three of the six tests needed to verify that the effluent monitoring system for the new Canister Storage Building ventilation exhaust stack meets applicable regulatory performance criteria for air sampling systems at nuclear facilities. These performance criteria address both the suitability of the location for the air-sampling probe and the transport of the sample to the collection devices. The criteria covering the location for the air-sampling probe ensure that the contaminants in the stack are well mixed with the airflow at the probe location such that the extracted sample represents the whole. The sample-transport criteria ensure that the sampled contaminants are quantitatively delivered to the collection device. The specific performance criteria are described in detail in this report. The tests reported here cover the contaminant tracer uniformity and particle delivery performance criteria. These criteria were successfully met. The other three tests were conducted by the start-up staff of Duke Engineering and Services Hanford Inc. (DESH) and reported elsewhere. The Canister Storage Building is located in the 200 East Area of the U.S. Department of Energy's Hanford Site near Richland, Washington. The new air-exhaust system was built under the W379 Project. The air sampling system features a probe with a single shrouded sampling nozzle, a sample delivery line, and a filter holder to collect the sample.

  15. Indoor air quality in a middle school, Part I: Use of CO2 as a tracer for effective ventilation.

    PubMed

    Scheff, P A; Paulius, V K; Huang, S W; Conroy, L M

    2000-11-01

    The overall objective of the study was to evaluate the indoor air quality at a middle school with an emphasis on characterizing baseline conditions. The focus of this article is on the relationship between occupancy and measured concentrations of carbon dioxide, and an evaluation of the use of carbon dioxide as a tracer for ventilation in the school. The school was characterized as having no health complaints, good maintenance schedules, no carpeting within the classrooms or hallways, and no significant remodeling, and its officials had agreed to allow the sampling to take place during school hours. Monitoring followed the guidelines recommended in the "Preliminary Draft: Conceptual Standardized EPA Protocol For Characterizing Indoor Air Quality in School Buildings." Four indoor locations including the cafeteria, a science classroom, an art classroom, and the lobby outside the main office, and one outdoor location were sampled for various environmental comfort and pollutant parameters for one week in February 1997. A consistent relationship between hourly occupancy and corresponding carbon dioxide concentrations was seen. Carbon dioxide concentrations in the cafeteria, art room, and lobby were within specified American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) guidelines for comfort (< 1000 ppm). The science room had the highest concentrations (frequently exceeding 1000 ppm) due to high occupancy and non-functioning unit ventilators. Measured ventilation rates were within specified ASHRAE guidelines for the art room, cafeteria, and lobby. The science room, which relied on natural ventilation only, was not able to meet the ASHRAE guideline on one of the three days studied. The use of a completely mixed space, one compartment mass balance model with estimated CO2 generation rates and measured CO2 concentrations is shown to be a useful method for evaluating ventilation. Modeled effective ventilation, air changes per hour, and mixing

  16. Overall Ventilation System Flow Network Calculation for Site Recommendation

    SciTech Connect

    Jeff J. Steinhoff

    2001-08-02

    The scope of this calculation is to determine ventilation system resistances, pressure drops, airflows, and operating cost estimates for the Site Recommendation (SR) design as detailed in the ''Site Recommendation Subsurface Layout'' (BSC (Bechtel SAIC Company) 2001a). The statutory limit for emplacement of waste in Yucca Mountain is 70,000 metric tons of uranium (MTU) and is considered the base case for this report. The objective is to determine the overall repository system ventilation flow network for the monitoring phase during normal operations and to provide a basis for the system description document design descriptions. Any values derived from this calculation will not be used to support construction, fabrication, or procurement. The work scope is identified in the ''Technical Work Plan for Subsurface Design Section FY01 Work Activities'' (CRWMS M&O 2001, pp. 6 and 13). In accordance with the technical work plan this calculation was prepared in accordance with AP-3.12Q, ''Calculations'' and other procedures invoked by AP-3.12Q. It also incorporates the procedure AP-SI1.Q, ''Software Management''.

  17. Air heating system

    DOEpatents

    Primeau, John J.

    1983-03-01

    A self-starting, fuel-fired, air heating system including a vapor generator, a turbine, and a condenser connected in a closed circuit such that the vapor output from the vapor generator is conducted to the turbine and then to the condenser where it is condensed for return to the vapor generator. The turbine drives an air blower which passes air over the condenser for cooling the condenser. Also, a condensate pump is driven by the turbine. The disclosure is particularly concerned with the provision of heat exchanger and circuitry for cooling the condensed fluid output from the pump prior to its return to the vapor generator.

  18. Semi-volatile organic compounds in heating, ventilation, and air-conditioning filter dust in retail stores.

    PubMed

    Xu, Y; Liang, Y; Urquidi, J R; Siegel, J A

    2015-02-01

    Retail stores contain a wide range of products that can emit a variety of indoor pollutants. Among these chemicals, phthalate esters and polybrominated diphenyl ethers (PBDEs) are two important categories of semi-volatile organic compounds (SVOCs). Filters in heating, ventilation, and air-conditioning (HVAC) system collect particles from large volumes of air and thus potentially provide spatially and temporally integrated SVOC concentrations. This study measured six phthalate and 14 PBDE compounds in HVAC filter dust in 14 retail stores in Texas and Pennsylvania, United States. Phthalates and PBDEs were widely found in the HVAC filter dust in retail environment, indicating that they are ubiquitous indoor pollutants. The potential co-occurrence of phthalates and PBDEs was not strong, suggesting that their indoor sources are diverse. The levels of phthalates and PBDEs measured in HVAC filter dust are comparable to concentrations found in previous investigations of settled dust in residential buildings. Significant correlations between indoor air and filter dust concentrations were found for diethyl phthalate, di-n-butyl phthalate, and benzyl butyl phthalate. Reasonable agreement between measurements and an equilibrium model to describe SVOC partitioning between dust and gas-phase is achieved.

  19. FLOW-i ventilator performance in the presence of a circle system leak.

    PubMed

    Lucangelo, Umberto; Ajčević, Miloš; Accardo, Agostino; Borelli, Massimo; Peratoner, Alberto; Comuzzi, Lucia; Zin, Walter A

    2017-04-01

    Recently, the FLOW-i anaesthesia ventilator was developed based on the SERVO-i intensive care ventilator. The aim of this study was to test the FLOW-i's tidal volume delivery in the presence of a leak in the breathing circuit. We ventilated a test lung model in volume-, pressure-, and pressure-regulated volume-controlled modes (VC, PC, and PRVC, respectively) with a FLOW-i. First, the circuit remained airtight and the ventilator was tested with fresh gas flows of 6, 1, and 0.3 L/min in VC, PC, and PRVC modes and facing 4 combinations of different resistive and elastic loads. Second, a fixed leak in the breathing circuit was introduced and the measurements repeated. In the airtight system, FLOW-i maintained tidal volume (VT) and circuit pressure at approximately the set values, independently of respiratory mode, load, or fresh gas flow. In the leaking circuit, set VT = 500 mL, FLOW-i delivered higher VTs in PC (about 460 mL) than in VC and PRVC, where VTs were substantially less than 500 mL. Interestingly, VT did not differ appreciably from 6 to 0.3 L/min of fresh air flow among the 3 ventilatory modes. In the absence of leakage, peak inspiratory pressures were similar, while they were 35-45 % smaller in PRVC and VC than in PC mode in the presence of leaks. In conclusion, FLOW-i maintained VT (down to fresh gas flows of 0.3 L/min) to 90 % of its preset value in PC mode, which was 4-5 times greater than in VC or PRVC modes.

  20. Engineering Evaluation of the Effectiveness of DST Annulus Ventilation Systems for Corrosion Mitigation

    SciTech Connect

    DALPIAZ, E.L.

    2001-06-20

    This engineering study evaluates the corrosion mitigation effectiveness of the annulus ventilation systems for the 241-AN, 241-AP, 241-AW, 241-AY, 241-AZ, and 241-SY tank farms, and provides the technical basis for the Administrative Control for DST annulus ventilation systems. The study shows that maintenance of annulus ventilation is important to mitigating risk of condensation and resulting corrosion due to postulated water ingress into DST annuli.

  1. Effects of Temperature, Humidity and Air Flow on Fungal Growth Rate on Loaded Ventilation Filters.

    PubMed

    Tang, W; Kuehn, T H; Simcik, Matt F

    2015-01-01

    This study compares the fungal growth ratio on loaded ventilation filters under various temperature, relative humidity (RH), and air flow conditions in a controlled laboratory setting. A new full-size commercial building ventilation filter was loaded with malt extract nutrients and conidia of Cladosporium sphaerospermum in an ASHRAE Standard 52.2 filter test facility. Small sections cut from this filter were incubated under the following conditions: constant room temperature and a high RH of 97%; sinusoidal temperature (with an amplitude of 10°C, an average of 23°C, and a period of 24 hr) and a mean RH of 97%; room temperature and step changes between 97% and 75% RH, 97% and 43% RH, and 97% and 11% RH every 12 hr. The biomass on the filter sections was measured using both an elution-culture method and by ergosterol assay immediately after loading and every 2 days up to 10 days after loading. Fungal growth was detected earlier using ergosterol content than with the elution-culture method. A student's t-test indicated that Cladosporium sphaerospermum grew better at the constant room temperature condition than at the sinusoidal temperature condition. By part-time exposure to dry environments, the fungal growth was reduced (75% and 43% RH) or even inhibited (11% RH). Additional loaded filters were installed in the wind tunnel at room temperature and an RH greater than 95% under one of two air flow test conditions: continuous air flow or air flow only 9 hr/day with a flow rate of 0.7 m(3)/s (filter media velocity 0.15 m/s). Swab tests and a tease mount method were used to detect fungal growth on the filters at day 0, 5, and 10. Fungal growth was detected for both test conditions, which indicates that when temperature and relative humidity are optimum, controlling the air flow alone cannot prevent fungal growth. In real applications where nutrients are less sufficient than in this laboratory study, fungal growth rate may be reduced under the same operating conditions.

  2. The role of the US Department of Energy in indoor air quality and building ventilation policy development

    SciTech Connect

    Traynor, G.W.; Talbott, J.M.; Moses, D.O.

    1993-07-01

    Building ventilation consumes about 5.8 exajoules of energy each year in the US The annual cost of this energy, used for commercial building fans (1.6 exajoules) and the heating and cooling of outside air (4.2 exajoules), is about $US 33 billion per year. Energy conservation measures that reduce heating and cooling season ventilation rates 15 to 35% in commercial and residential buildings can result in a national savings of about 0.6 to 1.5 exajoules ($US 3-8 billion) per year assuming no reduction of commercial building fan energy use. The most significant adverse environmental impact of reduced ventilation and infiltration is the potential degradation of the buildings indoor air quality. Potential benefits to the US from the implementation of sound indoor air quality and building ventilation reduction policies include reduced building-sector energy consumption; reduced indoor, outdoor, and global air pollution; reduced product costs; reduced worker absenteeism; reduced health care costs; reduced litigation; increased worker well-being and productivity; and increased product quality and competitiveness.

  3. An overview of the TA-55, Building PF-4 ventilation system

    SciTech Connect

    1994-02-22

    An overview of the TA-55, Building PF-4 ventilation system is provided in the following sections. Included are descriptions of the zone configurations, equipment-performance criteria, ventilation support systems, and the ventilation-system evaluation criteria. Section 4.2.1.1 provides a brief discussion of the ventilation system function. Section 4.2.1.2 provides details on the overall system configuration. Details of system interfaces and support systems are provided in Section 4.2.1.3. Section 4.2.1.4 describes instrumentation and control needed to operate the ventilation system. Finally, Sections 4.2.1.5 and 4.2.1.6 describe system surveillance/maintenance and Technical Safety Requirements (TSR) Limitations, respectively. Note that the numerical parameters included in this description are considered nominal; set points and other specifications actually fall within operational bands.

  4. Air injection system diagnostic

    SciTech Connect

    Kotzan, J.M.; Labus, G.E.

    1992-05-19

    This patent describes a method for diagnosing failures in an air control system that controls a quantity of air admitted into an exhaust path of an internal combustion engine. It comprises sensing the oxygen content of the exhaust gas of the engine at predetermined time intervals at a first predetermined point in the exhaust path of the engine, the oxygen content normally oscillating between a rich oxygen condition and a lean oxygen condition in the absence of air injected into the exhaust path above the first predetermined point; injecting a quantity of air into the exhaust path of the engine at a second predetermined point in the exhaust port, the second predetermined point being above the first predetermined point; counting the number of intervals at which the sensed oxygen content indicates a rich oxygen condition over a predetermined period of time; comparing the counted number of rich oxygen intervals to a predetermined threshold value, the threshold value being greater than a counted number of rich oxygen intervals over the predetermined period of time resulting from the normal oscillations between rich and lean oxygen conditions in the absence of air injected into the exhaust path; indicating the existence of a fault in the air control system when the number of rich oxygen intervals does not exceed the predetermined threshold value.

  5. A simplified model for estimating population-scale energy impacts of building envelope air-tightening and mechanical ventilation retrofits

    SciTech Connect

    Logue, J. M.; Turner, W. J.N.; Walker, I. S.; Singer, B. C.

    2015-07-01

    Changing the air exchange rate of a home (the sum of the infiltration and mechanical ventilation airflow rates) affects the annual thermal conditioning energy. Large-scale changes to air exchange rates of the housing stock can significantly alter the residential sector’s energy consumption. However, the complexity of existing residential energy models is a barrier to the accurate quantification of the impact of policy changes on a state or national level.

  6. Dental Compressed Air Systems.

    DTIC Science & Technology

    1992-03-01

    I AL-TR-IWI-0uuu AD-A249 954 DENTAL COMPRESSED AIMYTM R Curtis D. Weyrmuch, Mejor, USAP, D Samuel P.Dvs iueatclpi SF.O N AEROSPACE MwaEDIN mwr~ComA G...FUNDING NUMBERS Dental Compressed Air Systems PE - 87714F PR - 7350 TA - 22 D. Weyrauch WU - XX Samuel P. Davis George W. Gaines 7. PERFORMING...words) The purpose of this report is to update guidelines on dental compressed air systems (DCA). Much of the information was obtained from a survey

  7. Review of low-energy construction, air tightness, ventilation strategies and indoor radon: results from Finnish houses and apartments.

    PubMed

    Arvela, H; Holmgren, O; Reisbacka, H; Vinha, J

    2014-12-01

    Low-energy and passive house construction practices are characterised by increased insulation, high air tightness of the building shell and controlled mechanical ventilation with heat recovery. As a result of the interaction of mechanical ventilation and high air tightness, the pressure difference in a building can be markedly enhanced. This may lead to elevated indoor radon levels. Minor leakages in the foundation can affect the radon concentration, even in the case where such leaks do not markedly reduce the total air tightness. The potential for high pressures to affect indoor radon concentrations markedly increases when the air tightness ACH50, i.e. the air change per hour induced by a pressure difference of 50 Pa, is <1.0 h(-1). Pressure differences in Finnish low-rise residential houses having mechanical supply and exhaust ventilation with heat recovery (MSEV) are typically 2-3 Pa, clearly lower than the values of 5-9 Pa in houses with only mechanical exhaust ventilation (MEV). In MSEV houses, radon concentrations are typically 30% lower than in MEV houses. In new MSEV houses with an ACH50 of 0.6 h(-1), the limit for passive construction, the analytical estimates predict an increase of 100% in the radon concentration compared with older houses with an ACH50 of 4.0 h(-1). This poses a challenge for efficient radon prevention in new construction. Radon concentrations are typically 30% lower in houses with two storeys compared with only one storey. The introduction of an MSEV ventilation strategy in typically very airtight apartments has markedly reduced pressure differences and radon concentrations.

  8. Laboratory evaluation of welder's exposure and efficiency of air duct ventilation for welding work in a confined space.

    PubMed

    Ojima, J; Shibata, N; Iwasaki, T

    2000-01-01

    CO2 arc welding in a confined space was simulated in a laboratory by manipulating a welding robot which worked in a small chamber to experimentally evaluate the welder's exposure to welding fumes, ozone and carbon monoxide (CO). The effects of the welding arc on the air temperature rise and oxygen (O2) concentration in the chamber were also investigated. The measuring points for these items were located in the presumed breathing zone of a welder in a confined space. The time averaged concentrations of welding fumes, ozone and CO during the arcing time were 83.55 mg/m3, 0.203 ppm and 0.006%, respectively, at a welding current of 120A-200A. These results suggest serious exposure of a welder who operates in a confined space. Air temperature in the chamber rose remarkably due to the arc heat and the increase in the welding current. No clear decrease in the O2 concentration in the chamber was recognized during this welding operation. A model of air duct ventilation was constructed in the small chamber to investigate the strategy of effective ventilation for hazardous welding contaminants in a confined space. With this model we examined ventilation efficiency with a flow rate of 1.08-1.80 m3/min (ventilation rate for 0.40-0.67 air exchanges per minute) in the chamber, and proved that the exposure level was not drastically reduced during arcing time by this air duct ventilation, but the residual contaminants were rapidly exhausted after the welding operation.

  9. Microclimate measuring and fluid‑dynamic simulation in an industrial broiler house: testing of an experimental ventilation system.

    PubMed

    Bianchi, Biagio; Giametta, Ferruccio; La Fianza, Giovanna; Gentile, Andrea; Catalano, Pasquale

    2015-01-01

    The environment in the broiler house is a combination of physical and biological factors generating a complex dynamic system of interactions between birds, husbandry system, light, temperature, and the aerial environment. Ventilation plays a key role in this scenario. It is pivotal to remove carbon dioxide and water vapor from the air of the hen house. Adequate ventilation rates provide the most effective method of controlling temperature within the hen house. They allow for controlling the relative humidity and can play a key role in alleviating the negative effects of high stocking density and of wet litter. In the present study the results of experimental tests performed in a breeding broiler farm are shown. In particular the efficiency of a semi transversal ventilation system was studied against the use of a pure transversal one. In order to verify the efficiency of the systems, fluid dynamic simulations were carried out using the software Comsol multiphysics. The results of this study show that a correct architectural and structural design of the building must be supported by a design of the ventilation system able to maintain the environmental parameters within the limits of the thermo‑neutral and welfare conditions and to achieve the highest levels of productivity.

  10. Development of an Integrated Residential Heating, Ventilation, Cooling, and Dehumidification System for Residences

    SciTech Connect

    Hoeschele, M.A.; D.A. Springer

    2008-06-18

    The Need and the Opportunity Codes such as ASHRAE 90.2 and IECC, and programs such as Energy Star and Builders Challenge, are causing new homes to be built to higher performance standards. As a result sensible cooling loads in new homes are going down, but indoor air quality prerogatives are causing ventilation rates and moisture loads to increase in humid climates. Conventional air conditioners are unable to provide the low sensible heat ratios that are needed to efficiently cool and dehumidify homes since dehumidification potential is strongly correlated with cooling system operating hours. The project team saw an opportunity to develop a system that is at least as effective as a conventional air conditioner plus dehumidifier, removes moisture without increasing the sensible load, reduces equipment cost by integrating components, and simplifies installation. Project Overview Prime contractor Davis Energy Group led a team in developing an Integrated Heating, Ventilation, Cooling, and Dehumidification (I-HVCD) system under the DOE SBIR program. Phase I and II SBIR project activities ran from July 2003 through December 2007. Tasks included: (1) Mechanical Design and Prototyping; (2) Controls Development; (3) Laboratory and Field Testing; and (4) Commercialization Activities Technology Description. Key components of the prototype I-HVCD system include an evaporator coil assembly, return and outdoor air damper, and controls. These are used in conjunction with conventional components that include a variable speed air handler or furnace, and a two-stage condensing unit. I-HVCD controls enable the system to operate in three distinct cooling modes to respond to indoor temperature and relative humidity (RH) levels. When sensible cooling loads are high, the system operates similar to a conventional system but varies supply airflow in response to indoor RH. In the second mode airflow is further reduced, and the reheat coil adds heat to the supply air. In the third mode, the

  11. Evaluation of a Shaker Dust Collector for Use in a Recirculating Ventilation System.

    PubMed

    Peters, Thomas M; Sawvel, Russell A; Park, Jae Hong; Anthony, T Renée

    2015-01-01

    General ventilation with recirculated air may be cost-effective to control the concentration of low-toxicity, contaminants in workplaces with diffuse, dusty operations, such as in agriculture. Such systems are, however, rarely adopted with little evidence showing improved air quality and ability to operate under harsh conditions. The goal of this work was to examine the initial and long-term performance of a fabric-filter shaker dust collector (SDC) in laboratory tests and as deployed within a recirculating ventilation system in an agricultural building. In laboratory tests, collection efficiency and pressure drop were tracked over several filter loading cycles, and the recovery of filter capacity (pressure drop) from filter shaking was examined. Collection efficiencies of particles larger than 5 μm was high (>95%) even when the filter was pristine, showing effective collection of large particles that dominate inhalable concentrations typical of agricultural dusts. For respirable-sized particles, collection efficiencies were low when the filter was pristine (e.g., 27% for 1 μm) but much higher when a dust cake developed on the filter (>99% for all size particles), even after shaking (e.g., 90% for 1 μm). The first shake of a filter was observed to recovery a substantial fraction of filter capacity, with subsequent shakes providing little benefit. In field tests, the SDC performed effectively over a period of three months in winter when incorporated in a recirculating ventilation system of a swine farrowing room. Trends in collection efficiency and pressure drop with loading were similar to those observed in the laboratory with overall collection efficiencies high (>80%) when pressure drop exceeded 230 Pa, or 23% of the maximum loading recommended by the manufacturer. This work shows that the SDC can function effectively over the harsh winter in swine rearing operations. Together with findings of improved air quality in the farrowing room reported in a

  12. Evaluation of a Shaker Dust Collector for Use in a Recirculating Ventilation System

    PubMed Central

    Sawvel, Russell A.; Park, Jae Hong; Anthony, T. Renée

    2016-01-01

    General ventilation with recirculated air may be cost-effective to control the concentration of low-toxicity, contaminants in workplaces with diffuse, dusty operations, such as in agriculture. Such systems are, however, rarely adopted with little evidence showing improved air quality and ability to operate under harsh conditions. The goal of this work was to examine the initial and long-term performance of a fabric-filter shaker dust collector (SDC) in laboratory tests and as deployed within a recirculating ventilation system in an agricultural building. In laboratory tests, collection efficiency and pressure drop were tracked over several filter loading cycles, and the recovery of filter capacity (pressure drop) from filter shaking was examined. Collection efficiencies of particles larger than 5 μm was high (>95%) even when the filter was pristine, showing effective collection of large particles that dominate inhalable concentrations typical of agricultural dusts. For respirable-sized particles, collection efficiencies were low when the filter was pristine (e.g., 27% for 1 μm) but much higher when a dust cake developed on the filter (>99% for all size particles), even after shaking (e.g., 90% for 1 μm). The first shake of a filter was observed to recovery a substantial fraction of filter capacity, with subsequent shakes providing little benefit. In field tests, the SDC performed effectively over a period of three months in winter when incorporated in a recirculating ventilation system of a swine farrowing room. Trends in collection efficiency and pressure drop with loading were similar to those observed in the laboratory with overall collection efficiencies high (>80%) when pressure drop exceeded 230 Pa, or 23% of the maximum loading recommended by the manufacturer. This work shows that the SDC can function effectively over the harsh winter in swine rearing operations. Together with findings of improved air quality in the farrowing room reported in a companion

  13. Balancing energy conservation and occupant needs in ventilation rate standards for Big Box stores and other commercial buildings in California. Issues related to the ASHRAE 62.1 Indoor Air Quality Procedure

    SciTech Connect

    Mendell, Mark J.; Apte, Mike G.

    2010-10-31

    This report considers the question of whether the California Energy Commission should incorporate the ASHRAE 62.1 ventilation standard into the Title 24 ventilation rate (VR) standards, thus allowing buildings to follow the Indoor Air Quality Procedure. This, in contrast to the current prescriptive standard, allows the option of using ventilation rate as one of several strategies, which might include source reduction and air cleaning, to meet specified targets of indoor air concentrations and occupant acceptability. The research findings reviewed in this report suggest that a revised approach to a ventilation standard for commercial buildings is necessary, because the current prescriptive ASHRAE 62.1 Ventilation Rate Procedure (VRP) apparently does not provide occupants with either sufficiently acceptable or sufficiently healthprotective air quality. One possible solution would be a dramatic increase in the minimum ventilation rates (VRs) prescribed by a VRP. This solution, however, is not feasible for at least three reasons: the current need to reduce energy use rather than increase it further, the problem of polluted outdoor air in many cities, and the apparent limited ability of increasing VRs to reduce all indoor airborne contaminants of concern (per Hodgson (2003)). Any feasible solution is thus likely to include methods of pollutant reduction other than increased outdoor air ventilation; e.g., source reduction or air cleaning. The alternative 62.1 Indoor Air Quality Procedure (IAQP) offers multiple possible benefits in this direction over the VRP, but seems too limited by insufficient specifications and inadequate available data to provide adequate protection for occupants. Ventilation system designers rarely choose to use it, finding it too arbitrary and requiring use of much non-engineering judgment and information that is not readily available. This report suggests strategies to revise the current ASHRAE IAQP to reduce its current limitations. These

  14. HOW THE LEED VENTILATION CREDIT IMPACTS ENERGY CONSUMPTION OF GSHP SYSTEMS A CASE STUDY FOR PRIMARY SCHOOLS

    SciTech Connect

    Liu, Xiaobing

    2011-01-01

    This paper presents a study on the impacts of increased outdoor air (OA) ventilation on the performance of ground-source heat pump (GSHP) systems that heat and cool typical primary schools. Four locations Phoenix, Miami, Seattle, and Chicago are selected in this study to represent different climate zones in the United States. eQUEST, an integrated building and HVAC system energy analysis program, is used to simulate a typical primary school and the GSHP system at the four locations with minimum and 30% more than minimum OA ventilation. The simulation results show that, without an energy recovery ventilator, the 30% more OA ventilation results in an 8.0 13.3% increase in total GSHP system energy consumption at the four locations. The peak heating and cooling loads increase by 20.2 30% and 14.9 18.4%, respectively, at the four locations. The load imbalance of the ground heat exchanger is increased in hot climates but reduced in mild and cold climates.

  15. Measured performance of filtration and ventilation systems for fine and ultrafine particles and ozone in an unoccupied modern California house.

    PubMed

    Singer, B C; Delp, W W; Black, D R; Walker, I S

    2016-12-05

    This study evaluated nine ventilation and filtration systems in an unoccupied 2006 house located 250 m downwind of the I-80 freeway in Sacramento, California. Systems were evaluated for reducing indoor concentrations of outdoor particles in summer and fall/winter, ozone in summer, and particles from stir-fry cooking. Air exchange rate was measured continuously. Energy use was estimated for year-round operation in California. Exhaust ventilation without enhanced filtration provided indoor PM2.5 that was 70% lower than outdoors. Supply ventilation with MERV13 filtration provided slightly less protection, whereas supply MERV16 filtration reduced PM2.5 by 97-98% relative to outdoors. Supply filtration systems used little energy but provided no benefits for indoor-generated particles. Systems with MERV13-16 filter in the recirculating heating and cooling unit (FAU) operating continuously or 20 min/h reduced PM2.5 by 93-98%. Across all systems, removal percentages were higher for ultrafine particles and lower for black carbon, relative to PM2.5 . Indoor ozone was 3-4% of outdoors for all systems except an electronic air cleaner that produced ozone. Filtration via the FAU or portable filtration units lowered PM2.5 by 25-75% when operated over the hour following cooking. The energy for year-round operation of FAU filtration with an efficient blower motor was estimated at 600 kWh/year.

  16. Thermal comfort in the humid tropics: Field experiments in air conditioned and naturally ventilated buildings in Singapore

    NASA Astrophysics Data System (ADS)

    de Dear, R. J.; Leow, K. G.; Foo, S. C.

    1991-12-01

    Thermal comfort field experiments were conducted in Singapore in both naturally ventilated highrise residential buildings and air conditioned office buildings. Each of the 818 questionnaire responses was made simultaneously with a detailed set of indoor climatic measurements, and estimates of clothing insulation and metabolic rate. Results for the air conditioned sample indicated that office buildings were overcooled, causing up to one-third of their occupants to experience cool thermal comfort sensations. These observations in air conditioned buildings were broadly consistent with the ISO, ASHRAE and Singapore indoor climatic standards. Indoor climates of the naturally ventilated apartments during the day and early evening were on average three degrees warmer than the ISO comfort standard prescriptions, but caused much less thermal discomfort than expected. Discrepancies between thermal comfort responses in apartment blocks and office buildings are discussed in terms of contemporary perceptual theory.

  17. Human paranasal sinuses and selective brain cooling: a ventilation system activated by yawning?

    PubMed

    Gallup, Andrew C; Hack, Gary D

    2011-12-01

    The function of the paranasal sinuses has been a controversial subject since the time of Galen, with many different theories advanced about their biological significance. For one, the paranasal sinuses have been regarded as warmers of respiratory air, when in actuality these structures appear to function in cooling the blood. In fact, human paranasal sinuses have been shown to have higher volumes in individuals living in warmer climates, and thus may be considered radiators of the brain. The literature suggests that the transfer of cool venous blood from the paranasal sinuses to the dura mater may provide a mechanism for the convection process of cooling produced by the evaporation of mucus within human sinuses. In turn, the dura mater may transmit these temperature changes, initiated by the cool venous blood from the heat-dissipating surfaces of the sinuses, to the cerebrospinal fluid compartments. Furthermore, it has recently been demonstrated in cadaveric dissections that the thin bony posterior wall of the maxillary sinus serves as an origin for both medial and lateral pterygoid muscle segments, an anatomic finding that had been previously underappreciated in the literature. The present authors hypothesize that the thin posterior wall of the maxillary sinus may flex during yawning, operating like a bellows pump, actively ventilating the sinus system, and thus facilitating brain cooling. Such a powered ventilation system has not previously been described in humans, although an analogous system has been reported in birds.

  18. ETS levels in hospitality environments satisfying ASHRAE standard 62-1989: "ventilation for acceptable indoor air quality"

    NASA Astrophysics Data System (ADS)

    Moschandreas, D. J.; Vuilleumier, K. L.

    Prior to this study, indoor air constituent levels and ventilation rates of hospitality environments had not been measured simultaneously. This investigation measured indoor Environmental Tobacco Smoke-related (ETS-related) constituent levels in two restaurants, a billiard hall and a casino. The objective of this study was to characterize ETS-related constituent levels inside hospitality environments when the ventilation rates satisfy the requirements of the ASHRAE 62-1989 Ventilation Standard. The ventilation rate of each selected hospitality environment was measured and adjusted. The study advanced only if the requirements of the ASHRAE 62-1989 Ventilation Standard - the pertinent standard of the American Society of Heating, Refrigeration and Air Conditioning Engineers - were satisfied. The supply rates of outdoor air and occupant density were measured intermittently to assure that the ventilation rate of each facility satisfied the standard under occupied conditions. Six ETS-related constituents were measured: respirable suspended particulate (RSP) matter, fluorescent particulate matter (FPM, an estimate of the ETS particle concentrations), ultraviolet particulate matter (UVPM, a second estimate of the ETS particle concentrations), solanesol, nicotine and 3-ethenylpyridine (3-EP). ETS-related constituent levels in smoking sections, non-smoking sections and outdoors were sampled daily for eight consecutive days at each hospitality environment. This study found that the difference between the concentrations of ETS-related constituents in indoor smoking and non-smoking sections was statistically significant. Differences between indoor non-smoking sections and outdoor ETS-related constituent levels were identified but were not statistically significant. Similarly, differences between weekday and weekend evenings were identified but were not statistically significant. The difference between indoor smoking sections and outdoors was statistically significant. Most

  19. Air System Information Management

    NASA Technical Reports Server (NTRS)

    Filman, Robert E.

    2004-01-01

    I flew to Washington last week, a trip rich in distributed information management. Buying tickets, at the gate, in flight, landing and at the baggage claim, myriad messages about my reservation, the weather, our flight plans, gates, bags and so forth flew among a variety of travel agency, airline and Federal Aviation Administration (FAA) computers and personnel. By and large, each kind of information ran on a particular application, often specialized to own data formats and communications network. I went to Washington to attend an FAA meeting on System-Wide Information Management (SWIM) for the National Airspace System (NAS) (http://www.nasarchitecture.faa.gov/Tutorials/NAS101.cfm). NAS (and its information infrastructure, SWIM) is an attempt to bring greater regularity, efficiency and uniformity to the collection of stovepipe applications now used to manage air traffic. Current systems hold information about flight plans, flight trajectories, weather, air turbulence, current and forecast weather, radar summaries, hazardous condition warnings, airport and airspace capacity constraints, temporary flight restrictions, and so forth. Information moving among these stovepipe systems is usually mediated by people (for example, air traffic controllers) or single-purpose applications. People, whose intelligence is critical for difficult tasks and unusual circumstances, are not as efficient as computers for tasks that can be automated. Better information sharing can lead to higher system capacity, more efficient utilization and safer operations. Better information sharing through greater automation is possible though not necessarily easy.

  20. Design and Integrate Improved Systems for Nuclear Facility Ventilation and Exhaust Operations

    SciTech Connect

    Moore, Murray E.

    2014-04-15

    Objective: The objective of this R&D project would complete the development of three new systems and integrate them into a single experimental effort. However, each of the three systems has stand-alone applicability across the DOE complex. At US DOE nuclear facilities, indoor air is filtered and ventilated for human occupancy, and exhaust air to the outdoor environment must be regulated and monitored. At least three technical standards address these functions, and the Los Alamos National Laboratory would complete an experimental facility to answer at least three questions: (1) Can the drag coefficient of a new Los Alamos air mixer be reduced for better operation in nuclear facility exhaust stacks? (2) Is it possible to verify the accuracy of a new dilution method for HEPA filter test facilities? (3) Is there a performance-based air flow metric (volumetric flow or mass flow) for operating HEPA filters? In summary, the three new systems are: a mixer, a diluter and a performance-based metric, respectively. The results of this project would be applicable to at least four technical standards: ANSI N13.1 Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities; ASTM F1471 Standard Test Method for Air Cleaning Performance of a High-Efficiency Particulate Air Filter System, ASME N511: In-Service Testing of Nuclear Air Treatment, Heating, Ventilating, and Air-Conditioning Systems, and ASME AG-1: Code On Nuclear Air And Gas Treatment. All of the three proposed new systems must be combined into a single experimental device (i.e. to develop a new function of the Los Alamos aerosol wind tunnel). Technical Approach: The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally (2006) designed to evaluate small air samplers (cf. US EPA 40 CFR 53.42). In 2009, the tunnel was modified for exhaust stack verifications per the ANSI N13.1 standard. In 2010, modifications were started on the

  1. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... ventilation system must be designed to provide each occupant with at least 0.55 pounds of fresh air per minute... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ventilation. 23.831 Section 23.831... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Personnel...

  2. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ventilation system must be designed to provide each occupant with at least 0.55 pounds of fresh air per minute... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ventilation. 23.831 Section 23.831... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Personnel...

  3. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ventilation system must be designed to provide each occupant with at least 0.55 pounds of fresh air per minute... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ventilation. 23.831 Section 23.831... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Personnel...

  4. Canyon building ventilation system dynamic model -- Parameters and validation

    SciTech Connect

    Moncrief, B.R. ); Chen, F.F.K. )

    1993-01-01

    Plant system simulation crosses many disciplines. At the core is the mimic of key components in the form of mathematical models.'' These component models are functionally integrated to represent the plant. With today's low cost high capacity computers, the whole plant can be truly and effectively reproduced in a computer model. Dynamic simulation has its roots in single loop'' design, which is still a common objective in the employment of simulation. The other common objectives are the ability to preview plant operation, to anticipate problem areas, and to test the impact of design options. As plant system complexity increases and our ability to simulate the entire plant grows, the objective to optimize plant system design becomes practical. This shift in objectives from problem avoidance to total optimization by far offers the most rewarding potential. Even a small reduction in bulk materials and space can sufficiently justify the application of this technology. Furthermore, to realize an optimal plant starts from a tight and disciplined design. We believe the assurance required to execute such a design strategy can partly be derived from a plant model. This paper reports on the application of a dynamic model to evaluate the capacity of an existing production plant ventilation system. This study met the practical objectives of capacity evaluation under present and future conditions, and under normal and accidental situations. More importantly, the description of this application, in its methods and its utility, aims to validate the technology of dynamic simulation in the environment of plant system design and safe operation.

  5. Energy and IAQ Implications of Residential Ventilation Cooling

    SciTech Connect

    Turner, William; Walker, Iain

    2014-08-01

    This study evaluates the energy, humidity and indoor air quality (IAQ) implications of residential ventilation cooling in all U.S. IECC climate zones. A computer modeling approach was adopted, using an advanced residential building simulation tool with airflow, energy and humidity models. An economizer (large supply fan) was simulated to provide ventilation cooling while outdoor air temperatures were lower than indoor air temperatures (typically at night). The simulations were performed for a full year using one-minute time steps to allow for scheduling of ventilation systems and to account for interactions between ventilation and heating/cooling systems.

  6. Air-storage systems

    SciTech Connect

    Doherty, T.J.

    1981-10-01

    The air storage system, the critical component making CAES technically and economically feasible, is described in three of its forms. All have geological containments and reflect economics of scale requiring fairly large plant ratings and storage capacities. All three systems also are based on good precedent experience and there are a number of willing bidders in the engineering and construction field attesting to the readiness of the technology. The salient features of each storage system type are summarized. Hard rock caverns have the widest siting opportunity in a variety of geology, are well within construction capability in good quality rock with maximum control of system design through engineering, have the highest cost of the storage system options study and the potential for longest time to startup, are difficult and expensive to expand for increased storage or plant rating. The salt-solutioned cavern has limited siting opportunities, is a very economical storage system, and storage increase is possible through cavern additions.

  7. Comparison of methods to evaluate the fungal biomass in heating, ventilation, and air-conditioning (HVAC) dust.

    PubMed

    Biyeyeme Bi Mve, Marie-Jeanne; Cloutier, Yves; Lacombe, Nancy; Lavoie, Jacques; Debia, Maximilien; Marchand, Geneviève

    2016-12-01

    Heating, ventilation, and air-conditioning (HVAC) systems contain dust that can be contaminated with fungal spores (molds), which may have harmful effects on the respiratory health of the occupants of a building. HVAC cleaning is often based on visual inspection of the quantity of dust, without taking the mold content into account. The purpose of this study is to propose a method to estimate fungal contamination of dust in HVAC systems. Comparisons of different analytical methods were carried out on dust deposited in a controlled-atmosphere exposure chamber. Sixty samples were analyzed using four methods: culture, direct microscopic spore count (DMSC), β-N-acetylhexosaminidase (NAHA) dosing and qPCR. For each method, the limit of detection, replicability, and repeatability were assessed. The Pearson correlation coefficients between the methods were also evaluated. Depending on the analytical method, mean spore concentrations per 100 cm(2) of dust ranged from 10,000 to 682,000. Limits of detection varied from 120 to 217,000 spores/100 cm(2). Replicability and repeatability were between 1 and 15%. Pearson correlation coefficients varied from -0.217 to 0.83. The 18S qPCR showed the best sensitivity and precision, as well as the best correlation with the culture method. PCR targets only molds, and a total count of fungal DNA is obtained. Among the methods, mold DNA amplification by qPCR is the method suggested for estimating the fungal content found in dust of HVAC systems.

  8. Air-storage systems

    NASA Astrophysics Data System (ADS)

    Doherty, T. J.

    1981-10-01

    The air storage system, the critical component making compressed air energy storage technically economically feasible, is described in three of its forms. All have geological containments and reflect economics of scale requiring fairly large plant ratings and storage capacities. All three systems also are based on good precedent experience and there are a number of willing bidders in the engineering and construction field attesting to the readiness of the technology. The salient features of each storage system type are summarized. Hard rock caverns have the widest siting opportunity with a variety of geology, are well within construction capability in good quality rock with maximum control of system design through engineering, and have the highest cost of the storage system options study. They have the potential for longest time to startup and are difficult and expensive to expand for increased storage or plant rating. The salt-solutioned cavern has limited siting opportunities, is a very economical storage system, and storage increase is possible through cavern additions.

  9. Carbon-dioxide-controlled ventilation study

    SciTech Connect

    McMordie, K.L.; Carroll, D.M.

    1994-05-01

    The In-House Energy Management (IHEM) Program has been established by the U.S. Department of Energy to provide funds to federal laboratories to conduct research on energy-efficient technology. The Energy Sciences Department of Pacific Northwest Laboratory (PNL) was tasked by IHEM to research the energy savings potential associated with reducing outdoor-air ventilation of buildings. By monitoring carbon dioxide (CO{sub 2}) levels in a building, outdoor air provided by the heating, ventilating, and air-conditioning (HVAC) system can be reduced to the percentage required to maintain satisfactory CO{sub 2} levels rather than ventilating with a higher outdoor-air percentage based on an arbitrary minimum outdoor-air setting. During summer months, warm outdoor air brought into a building for ventilation must be cooled to meet the appropriate cooling supply-air temperature, and during winter months, cold outdoor air must be heated. By minimizing the amount of hot or cold outdoor air brought into the HVAC system, the supply air requires less cooling or heating, saving energy and money. Additionally, the CO{sub 2} levels in a building can be monitored to ensure that adequate outdoor air is supplied to a building to maintain air quality levels. The two main considerations prior to implementing CO{sub 2}-based ventilation control are its impact on energy consumption and the adequacy of indoor air quality (IAQ) and occupant comfort. To address these considerations, six portable CO{sub 2} monitors were placed in several Hanford Site buildings to estimate the adequacy of office/workspace ventilation. The monitors assessed the potential for reducing the flow of outdoor-air to the buildings. A candidate building was also identified to monitor various ventilation control strategies for use in developing a plan for implementing and assessing energy savings.

  10. HVAC SYSTEMS AS A TOOL IN CONTROLLING INDOOR AIR QUALITY: A LITERATURE REVIEW

    EPA Science Inventory

    The report gives results of a review of literature on the use of heating, ventilating, and air-conditioning (HVAC) systems to control indoor air quality (IAQ). Although significant progress has been made in reducing the energy consumption of HVAC systems, their effect on indoor a...

  11. Final Report Balancing energy conservation and occupant needs in ventilation rate standards for Big Box stores in California. Predicted indoor air quality and energy consumption using a matrix of ventilation scenarios

    SciTech Connect

    Apte, Michael G.; Mendell, Mark J.; Sohn, Michael D.; Dutton, Spencer M.; Berkeley, Pam M.; Spears, Michael

    2011-02-01

    Through mass-balance modeling of various ventilation scenarios that might satisfy the ASHRAE 62.1 Indoor Air Quality (IAQ) Procedure, we estimate indoor concentrations of contaminants of concern (COCs) in California “big box” stores, compare estimates to available thresholds, and for selected scenarios estimate differences in energy consumption. Findings are intended to inform decisions on adding performance-based approaches to ventilation rate (VR) standards for commercial buildings. Using multi-zone mass-balance models and available contaminant source rates, we estimated concentrations of 34 COCs for multiple ventilation scenarios: VRmin (0.04 cfm/ft2 ), VRmax (0.24 cfm/ft2 ), and VRmid (0.14 cfm/ft2 ). We compared COC concentrations with available health, olfactory, and irritant thresholds. We estimated building energy consumption at different VRs using a previously developed EnergyPlus model. VRmax did control all contaminants adequately, but VRmin did not, and VRmid did so only marginally. Air cleaning and local ventilation near strong sources both showed promise. Higher VRs increased indoor concentrations of outdoor air pollutants. Lowering VRs in big box stores in California from VRmax to VRmid would reduce total energy use by an estimated 6.6% and energy costs by 2.5%. Reducing the required VRs in California’s big box stores could reduce energy use and costs, but poses challenges for health and comfort of occupants. Source removal, air cleaning, and local ventilation may be needed at reduced VRs, and even at current recommended VRs. Also, alternative ventilation strategies taking climate and season into account in ventilation schedules may provide greater energy cost savings than constant ventilation rates, while improving IAQ.

  12. A simplified model for estimating population-scale energy impacts of building envelope air-tightening and mechanical ventilation retrofits

    SciTech Connect

    Logue, Jennifer M.; Turner, William J. N.; Walker, Iain S.; Singer, Brett C.

    2015-01-19

    Changing the air exchange rate of a home (the sum of the infiltration and mechanical ventilation airflow rates) affects the annual thermal conditioning energy. Large-scale changes to air exchange rates of the housing stock can significantly alter the residential sector's energy consumption. However, the complexity of existing residential energy models is a barrier to the accurate quantification of the impact of policy changes on a state or national level. The Incremental Ventilation Energy (IVE) model developed in this study combines the output of simple air exchange models with a limited set of housing characteristics to estimate the associated change in energy demand of homes. The IVE model was designed specifically to enable modellers to use existing databases of housing characteristics to determine the impact of ventilation policy change on a population scale. The IVE model estimates of energy change when applied to US homes with limited parameterisation are shown to be comparable to the estimates of a well-validated, complex residential energy model.

  13. Future Air Force systems.

    PubMed

    Tremaine, S A

    1986-10-01

    Planning for the future is under way in earnest at the Aeronautical Systems Division (ASD) at Wright-Patterson Air Force Base. It has been statistically established that it takes from 14-16 years from the generation of a new system idea to enter into engineering development. With this unpleasing, but realistic, schedule in mind, ASD has, during the last 3 years, been initiating long-term planning projects that are pre-starts for new system ideas. They are generated from throughout the Air Force and are locally managed and funded. Through this process, which spans from 12-14 months, specific and revolutionary new ideas for the systems of the future are generated. This article addresses more than a dozen specific new ideas in work at ASD today. These ideas range from a need to replace the C-130 type aircraft after the year 2000 to planning a follow-on to the B-18 well into the 21st century. Among other specific projects are investigation into an immortal fighter intended to be free of reliability and maintenance demands for an especially long period of operation, a new training system and advanced trainer to replace the T-38, a transatmospheric vehicle that could operate in the 100,000-500,000 foot flight region (30,480-152,400 m), and a new means of defending against hostile cruise missile launchers and cruise missiles. Other ideas are also addressed. The article concludes with emphasis on systems that can operate hypersonically in and out of the known atmosphere and greater use of airbreathing propulsion systems operating between Mach 3 and Mach 6.

  14. Canyon building ventilation system dynamic model -- Parameters and validation

    SciTech Connect

    Moncrief, B.R.; Chen, F.F.K.

    1993-02-01

    Plant system simulation crosses many disciplines. At the core is the mimic of key components in the form of mathematical ``models.`` These component models are functionally integrated to represent the plant. With today`s low cost high capacity computers, the whole plant can be truly and effectively reproduced in a computer model. Dynamic simulation has its roots in ``single loop`` design, which is still a common objective in the employment of simulation. The other common objectives are the ability to preview plant operation, to anticipate problem areas, and to test the impact of design options. As plant system complexity increases and our ability to simulate the entire plant grows, the objective to optimize plant system design becomes practical. This shift in objectives from problem avoidance to total optimization by far offers the most rewarding potential. Even a small reduction in bulk materials and space can sufficiently justify the application of this technology. Furthermore, to realize an optimal plant starts from a tight and disciplined design. We believe the assurance required to execute such a design strategy can partly be derived from a plant model. This paper reports on the application of a dynamic model to evaluate the capacity of an existing production plant ventilation system. This study met the practical objectives of capacity evaluation under present and future conditions, and under normal and accidental situations. More importantly, the description of this application, in its methods and its utility, aims to validate the technology of dynamic simulation in the environment of plant system design and safe operation.

  15. Bleederless ventilation systems as a spontaneous combustion control measure in US coal mines. Information circular/1994

    SciTech Connect

    Smith, A.C.; Diamond, W.P.; Mucho, T.P.; Organiscak, J.A.

    1994-01-01

    The U.S. Bureau of Mines conducted a worldwide literature review of bleederless ventilation practices to evaluate their use as a spontaneous combustion control measure in U.S. coal mines. Factors that must be taken into account in the design and use of these systems include seal construction, the use of ventilation control devices, the use of methane-drainage systems in gassy mines, and the ground control plan. Monitoring for the detection of spontaneous combustion and the control of methane when methane-drainage techniques are employed is critical to the successful use of a bleederless ventilation system. The report describes the types of ventilation systems used throughout the world and the spontaneous combustion risks associated with these systems.

  16. Liquid ventilation

    PubMed Central

    Sarkar, Suman; Paswan, Anil; Prakas, S.

    2014-01-01

    Human have lungs to breathe air and they have no gills to breath liquids like fish. When the surface tension at the air-liquid interface of the lung increases as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV) is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen as the inert carrier of oxygen and carbon dioxide offers a number of advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. It is well-known that respiratory diseases are one of the most common causes of morbidity and mortality in intensive care unit. During the past few years several new modalities of treatment have been introduced. One of them and probably the most fascinating, is of LV. Partial LV, on which much of the existing research has concentrated, requires partial filling of lungs with perfluorocarbons (PFC's) and ventilation with gas tidal volumes using conventional mechanical ventilators. Various physico-chemical properties of PFC's make them the ideal media. It results in a dramatic improvement in lung compliance and oxygenation and decline in mean airway pressure and oxygen requirements. No long-term side-effect reported. PMID:25886321

  17. Air Mobile Utility Distribution Systems.

    DTIC Science & Technology

    WATER PIPES, AIR TRANSPORTABLE EQUIPMENT, POLYVINYL CHLORIDE, GLASS REINFORCED PLASTICS , FUEL HOSES, HOSES....PIPES, *PIPING SYSTEMS, INSULATION, FABRICATION, CORROSION INHIBITION, FEASIBILITY STUDIES, AIR FORCE FACILITIES, POLYURETHANE RESINS, PLASTICS

  18. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: NEW CONDENSATOR, INC.--THE CONDENSATOR DIESEL ENGINE RETROFIT CRANKCASE VENTILATION SYSTEM

    EPA Science Inventory

    EPA's Environmental Technology Verification Program has tested New Condensator Inc.'s Condensator Diesel Engine Retrofit Crankcase Ventilation System. Brake specific fuel consumption (BSFC), the ratio of engine fuel consumption to the engine power output, was evaluated for engine...

  19. Coal-packed methane biofilter for mitigation of green house gas emissions from coal mine ventilation air.

    PubMed

    Limbri, Hendy; Gunawan, Cindy; Thomas, Torsten; Smith, Andrew; Scott, Jason; Rosche, Bettina

    2014-01-01

    Methane emitted by coal mine ventilation air (MVA) is a significant greenhouse gas. A mitigation strategy is the oxidation of methane to carbon dioxide, which is approximately twenty-one times less effective at global warming than methane on a mass-basis. The low non-combustible methane concentrations at high MVA flow rates call for a catalytic strategy of oxidation. A laboratory-scale coal-packed biofilter was designed and partially removed methane from humidified air at flow rates between 0.2 and 2.4 L min-1 at 30°C with nutrient solution added every three days. Methane oxidation was catalysed by a complex community of naturally-occurring microorganisms, with the most abundant member being identified by 16S rRNA gene sequence as belonging to the methanotrophic genus Methylocystis. Additional inoculation with a laboratory-grown culture of Methylosinus sporium, as investigated in a parallel run, only enhanced methane consumption during the initial 12 weeks. The greatest level of methane removal of 27.2±0.66 g methane m-3 empty bed h-1 was attained for the non-inoculated system, which was equivalent to removing 19.7±2.9% methane from an inlet concentration of 1% v/v at an inlet gas flow rate of 1.6 L min-1 (2.4 min empty bed residence time). These results show that low-cost coal packing holds promising potential as a suitable growth surface and contains methanotrophic microorganisms for the catalytic oxidative removal of methane.

  20. Coal-Packed Methane Biofilter for Mitigation of Green House Gas Emissions from Coal Mine Ventilation Air

    PubMed Central

    Limbri, Hendy; Gunawan, Cindy; Thomas, Torsten; Smith, Andrew; Scott, Jason; Rosche, Bettina

    2014-01-01

    Methane emitted by coal mine ventilation air (MVA) is a significant greenhouse gas. A mitigation strategy is the oxidation of methane to carbon dioxide, which is approximately twenty-one times less effective at global warming than methane on a mass-basis. The low non-combustible methane concentrations at high MVA flow rates call for a catalytic strategy of oxidation. A laboratory-scale coal-packed biofilter was designed and partially removed methane from humidified air at flow rates between 0.2 and 2.4 L min−1 at 30°C with nutrient solution added every three days. Methane oxidation was catalysed by a complex community of naturally-occurring microorganisms, with the most abundant member being identified by 16S rRNA gene sequence as belonging to the methanotrophic genus Methylocystis. Additional inoculation with a laboratory-grown culture of Methylosinus sporium, as investigated in a parallel run, only enhanced methane consumption during the initial 12 weeks. The greatest level of methane removal of 27.2±0.66 g methane m−3 empty bed h−1 was attained for the non-inoculated system, which was equivalent to removing 19.7±2.9% methane from an inlet concentration of 1% v/v at an inlet gas flow rate of 1.6 L min−1 (2.4 min empty bed residence time). These results show that low-cost coal packing holds promising potential as a suitable growth surface and contains methanotrophic microorganisms for the catalytic oxidative removal of methane. PMID:24743729

  1. Project W-320 high vacuum 241-AY-102 annulus ventilation system operability test report

    SciTech Connect

    Bailey, J.W.

    1998-03-12

    This report documents the test results of OTP-320-001, Tank 241-AY-102 Annulus Ventilation System Testing. Included in the appendices are: (1) Supporting documentation prepared to demonstrate the structural integrity of the tank at high annulus vacuum (<20 INWG), and (2) a report that identifies potential cross connections between the primary and annulus ventilation systems. These cross connections were verified to be eliminated prior to the start of testing.

  2. Space station ventilation study

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.; Allen, G. E.

    1972-01-01

    A ventilation system design and selection method which is applicable to any manned vehicle were developed. The method was used to generate design options for the NASA 33-foot diameter space station, all of which meet the ventilation system design requirements. System characteristics such as weight, volume, and power were normalized to dollar costs for each option. Total system costs for the various options ranged from a worst case $8 million to a group of four which were all approximately $2 million. A system design was then chosen from the $2 million group and is presented in detail. A ventilation system layout was designed for the MSFC space station mockup which provided comfortable, efficient ventilation of the mockup. A conditioned air distribution system design for the 14-foot diameter modular space station, using the same techniques, is also presented. The tradeoff study resulted in the selection of a system which costs $1.9 million, as compared to the alternate configuration which would have cost $2.6 million.

  3. HVAC SYSTEMS AS EMISSION SOURCES AFFECTING INDOOR AIR QUALITY: A CRITICAL REVIEW

    EPA Science Inventory

    The paper discusses results of an evaluation of literature on heating, ventilating, and air-conditioning (HVAC) systems as contaminant emission sources that affect indoor air quality (IAQ). The various literature sources and methods for characterizing HVAC emission sources are re...

  4. 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.

  5. VENTILATION NEEDS DURING CONSTRUCTION

    SciTech Connect

    C.R. Gorrell

    1998-07-23

    The purpose of this analysis is to determine ventilation needs during construction and development of the subsurface repository and develop systems to satisfy those needs. For this analysis, construction is defined as pre-emplacement excavation and development is excavation that takes place simultaneously with emplacement. The three options presented in the ''Overall Development and Emplacement Ventilation Systems'' analysis (Reference 5.5) for development ventilation will be applied to construction ventilation in this analysis as well as adding new and updated ventilation factors to each option for both construction and development. The objective of this analysis is to develop a preferred ventilation system to support License Application Design. The scope of this analysis includes: (1) Description of ventilation conditions; (2) Ventilation factors (fire hazards, dust control, construction logistics, and monitoring and control systems); (3) Local ventilation alternatives; (4) Global ventilation options; and (5) Evaluation of options.

  6. Development of a Residential Integrated Ventilation Controller

    SciTech Connect

    Staff Scientist; Walker, Iain; Sherman, Max; Dickerhoff, Darryl

    2011-12-01

    The goal of this study was to develop a Residential Integrated Ventilation Controller (RIVEC) to reduce the energy impact of required mechanical ventilation by 20percent, maintain or improve indoor air quality and provide demand response benefits. This represents potential energy savings of about 140 GWh of electricity and 83 million therms of natural gas as well as proportional peak savings in California. The RIVEC controller is intended to meet the 2008 Title 24 requirements for residential ventilation as well as taking into account the issues of outdoor conditions, other ventilation devices (including economizers), peak demand concerns and occupant preferences. The controller is designed to manage all the residential ventilation systems that are currently available. A key innovation in this controller is the ability to implement the concept of efficacy and intermittent ventilation which allows time shifting of ventilation. Using this approach ventilation can be shifted away from times of high cost or high outdoor pollution towards times when it is cheaper and more effective. Simulations, based on the ones used to develop the new residential ventilation requirements for the California Buildings Energy code, were used to further define the specific criteria and strategies needed for the controller. These simulations provide estimates of the energy, peak power and contaminant improvement possible for different California climates for the various ventilation systems. Results from a field test of the prototype controller corroborate the predicted performance.

  7. 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

  8. Air Quality System (AQS) Metadata

    EPA Pesticide Factsheets

    The U.S. Environmental Protection Agency compiles air quality monitoring data in the Air Quality System (AQS). Ambient air concentrations are measured at a national network of more than 4,000 monitoring stations and are reported by state, local, and tribal

  9. Measuring Residential Ventilation System Airflows: Part 1 – Laboratory Evaluation of Airflow Meter Devices

    SciTech Connect

    Stratton, J. Chris; Turner, W. J. N.; Wray, Craig P.; Walker, Iain S.

    2012-11-30

    Building codes increasingly require tighter homes and mechanical ventilation per ASHRAE Standard 62.2. These ventilation flows must be measured so that energy is not wasted with over ventilation and occupants’ health is not compromised by under ventilation. Flow hoods are used to measure these ventilation flows, but there is currently no standard specifying the measurement procedure and measurement devices that should be used. This study evaluates the accuracy of six commercially available flow hoods under laboratory conditions configured to emulate a residential mechanical ventilation duct system. The measurements taken with the flow hoods were compared to simultaneous measurements taken by an in-line reference flow meter having a known uncertainty. Results indicate that powered flow hoods yield more accurate measurements than non-powered flow hoods, and that a majority of the flow hoods measured inlet flows more accurately than outlet flows. In several cases, there was little resemblance between the manufacturers’ stated accuracy and the accuracy we found in our laboratory measurements. It is clear that current flow hood calibration procedures may not consider field application variables such as flow asymmetry, flow angle, and flow direction. A new flow hood measurement standard that takes these ‘real world’ conditions into account should be developed to ensure that residential buildings receive the intended ventilation flows.

  10. Measuring Residential Ventilation System Airflows: Part 1 – Laboratory Evaluation of Airflow Meter Devices

    SciTech Connect

    Stratton, J. Chris; Turner, W. J. N.; Wray, Craig P.; Walker, Iain S.

    2012-11-12

    Building codes increasingly require tighter homes and mechanical ventilation per ASHRAE Standard 62.2. These ventilation flows must be measured so that energy is not wasted with over ventilation and occupants’ health is not compromised by under ventilation. Flow hoods are used to measure these ventilation flows, but there is currently no standard specifying the measurement procedure and measurement devices that should be used. This study evaluates the accuracy of six commercially available flow hoods under laboratory conditions configured to emulate a residential mechanical ventilation duct system. The measurements taken with the flow hoods were compared to simultaneous measurements taken by an in-line reference flow meter having a known uncertainty. Results indicate that powered flow hoods yield more accurate measurements than non-powered flow hoods, and that a majority of the flow hoods measured inlet flows more accurately than outlet flows. In several cases, there was little resemblance between the manufacturers’ stated accuracy and the accuracy we found in our laboratory measurements. It is clear that current flow hood calibration procedures may not consider field application variables such as flow asymmetry, flow angle, and flow direction. A new flow hood measurement standard that takes these ‘real world’ conditions into account should be developed to ensure that residential buildings receive the intended ventilation flows.

  11. Alternatives generation and analysis for double-shell tank primary ventilation systems emissions control and monitoring

    SciTech Connect

    SEDERBURG, J.P.

    1999-09-30

    This AGA addresses the question: ''What equipment upgrades, operational changes, and/or other actions are required relative to the DST tanks farms' ventilation systems to support retrieval, staging (including feed sampling), and delivery of tank waste to the Phase I private contractor?'' Issues and options for the various components within the ventilation subsystem affect each other. Recommended design requirements are presented and the preferred alternatives are detailed.

  12. [A computer-controlled closed circle system for ventilation during anesthesia and intensive care and its possibilities for patient monitoring].

    PubMed

    Verkaaik, A P; Rubreht, J; van Dijk, G; Westerkamp, B; Erdmann, W

    1991-01-01

    A computer feed back controlled anaesthesia- and intensive care ventilator has been developed with on-line and separate lung function measurement. The system design is built on the principle of a totally closed circuit (closed rebreathing respirometer) and an inspiratory "high flow", the gas being rotated through the closed circuit unidirectionally by a blower with 70 l/min. Ventilation is performed by metal membranes freely movable in membrane chambers with an internal part included into the closed circuit and an external part connected to pressurized air controlling inspiratory valves expiratory valves. The electronic valves are software controlled by the computer to exactly perform the desired preset ventilatory mode. Membrane movement are on-line measured capacitively and transformed into respective flow and volume values, whereby the compressibility of the system gas (on-line pressure recording) is taken into account. Volatile anaesthetic gases are feed back controlled to preset end expiratory values (MAC-controlled anaesthesia), circuit volume is maintained by N20-addition and oxygen is added to maintain the desired present inspiratory concentration measured with paramagnetic oxygen sensors. Ergonometric aspects led to the triangular from of the new anaesthesia and intensive care ventilator with the controlling service screen turnable to all three sides of the ventilator (high flexibility of the user) and all necessary equipment and material included into the "Anaesthesia workstation". All measured and present parameters are continuously displayed on the service (computer) screen and entered into the computer-memory in minute cycles with a memory capacity of 75 h anaesthesia. At any desired moment the memorized values can be transferred to IBM-compatible disc systems for storage or into the respective data management systems, thus at the end of anaesthesia, at the end of the working day or at the end of the week.

  13. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  14. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  15. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  16. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  17. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  18. Recommended Ventilation Strategies for Energy-Efficient Production Homes

    SciTech Connect

    Roberson, J.; Brown, R.; Koomey, J.; Warner, J.; Greenberg, S.

    1998-12-01

    This report evaluates residential ventilation systems for the U.S. Environmental Protection Agency's (EPA's) ENERGY STAR{reg_sign} Homes program and recommends mechanical ventilation strategies for new, low-infiltration, energy-efficient, single-family, ENERGY STAR production (site-built tract) homes in four climates: cold, mixed (cold and hot), hot humid, and hot arid. Our group in the Energy Analysis Department at Lawrence Berkeley National Lab compared residential ventilation strategies in four climates according to three criteria: total annualized costs (the sum of annualized capital cost and annual operating cost), predominant indoor pressure induced by the ventilation system, and distribution of ventilation air within the home. The mechanical ventilation systems modeled deliver 0.35 air changes per hour continuously, regardless of actual infiltration or occupant window-opening behavior. Based on the assumptions and analysis described in this report, we recommend independently ducted multi-port supply ventilation in all climates except cold because this strategy provides the safety and health benefits of positive indoor pressure as well as the ability to dehumidify and filter ventilation air. In cold climates, we recommend that multi-port supply ventilation be balanced by a single-port exhaust ventilation fan, and that builders offer balanced heat-recovery ventilation to buyers as an optional upgrade. For builders who continue to install forced-air integrated supply ventilation, we recommend ensuring ducts are airtight or in conditioned space, installing a control that automatically operates the forced-air fan 15-20 minutes during each hour that the fan does not operate for heating or cooling, and offering ICM forced-air fans to home buyers as an upgrade.

  19. Effects of Thermal Mass, Window Size, and Night-Time Ventilation on Peak Indoor Air Temperature in the Warm-Humid Climate of Ghana

    PubMed Central

    Amos-Abanyie, S.; Akuffo, F. O.; Kutin-Sanwu, V.

    2013-01-01

    Most office buildings in the warm-humid sub-Saharan countries experience high cooling load because of the predominant use of sandcrete blocks which are of low thermal mass in construction and extensive use of glazing. Relatively, low night-time temperatures are not harnessed in cooling buildings because office openings remain closed after work hours. An optimization was performed through a sensitivity analysis-based simulation, using the Energy Plus (E+) simulation software to assess the effects of thermal mass, window size, and night ventilation on peak indoor air temperature (PIAT). An experimental system was designed based on the features of the most promising simulation model, constructed and monitored, and the experimental data used to validate the simulation model. The results show that an optimization of thermal mass and window size coupled with activation of night-time ventilation provides a synergistic effect to obtain reduced peak indoor air temperature. An expression that predicts, indoor maximum temperature has been derived for models of various thermal masses. PMID:23878528

  20. Ventilation-Based Decellularization System of the Lung

    PubMed Central

    Tsuchiya, Tomoshi; Mendez, Julio; Calle, Elizabeth A.; Hatachi, Go; Doi, Ryoichiro; Zhao, Liping; Suematsu, Takashi; Nagayasu, Takeshi; Niklason, Laura E.

    2016-01-01

    Abstract The demand for donated organs greatly exceeds the availability. Alternatives to organ donation, such as laboratory-engineered organs, are therefore being developed. One approach is to decellularize the organ and reseed it with selected cells, ideally from the organ recipient. Organ decellularization has typically been attempted by the administration of detergents into vessels such as the portal vein in the liver. However, in the case of the lung, the airway provides another potential administration route, because it has a wide contact area between cells and detergents in the tracheal tree and alveoli. In the present study, we introduce a novel ventilation-based decellularization system for the lung and compare its efficacy to ordinary decellularization systems administering detergent through the pulmonary artery. Rat lungs were decellularized using 500 mL of 3-[(3-cholamidopropyl) dimethylammonio]-1-Propanesulfonate (CHAPS) decellularization solution administrated through the pulmonary artery (vessel group) or through the trachea (airway group). The vessel group was infused CHAPS solution using a gravitational pressure head of 20 cmH2O. The airway group was infused with the detergent using negative pressure and positive end-expiratory pressure, for a volume 10cc with each inspiration in a bioreactor. Pathological and immunohistochemical findings indicated that components of the extracellular matrix (ECM), including proteoglycans, elastic fibers, fibronectin, and laminin, were more decreased in the airway group than in the vessel group. Western blot analysis showed that MHC class I antigen and β-actin were not detected in both decellularized groups. A collagen assay showed that collagen was 70% preserved in both groups compared to native lung. Glycosaminoglycan (GAG) and DNA assays showed that GAG and DNA contents were strongly diminished in both decellularized groups, but those contents were smaller in the airway group than in the vessel group

  1. Helium:oxygen versus air:oxygen noninvasive positive-pressure ventilation in patients exposed to sulfur mustard.

    PubMed

    Ghanei, Mostafa; Rajaeinejad, Mohsen; Motiei-Langroudi, Rouzbeh; Alaeddini, Farshid; Aslani, Jafar

    2011-01-01

    Exposure to sulfur mustard (SM) causes a variety of respiratory symptoms, such as chronic bronchitis and constrictive bronchiolitis. This study assessed the effectiveness of noninvasive positive-pressure ventilation, adjunct with 79:21 helium:oxygen instead of 79:21 air:oxygen, in 24 patients with a previous exposure to SM presenting with acute respiratory failure. Both air:oxygen and helium:oxygen significantly decreased systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse rate, respiratory rate, dyspnea, and increased oxygen saturation (P values: .007, .029, .002, <.001, <.001, <.001, and .002 for air:oxygen, respectively, and <.001, .020, .001, <.001, <.001, <.001, and .002, for helium:oxygen, respectively). Moreover, helium:oxygen more potently improved systolic pressure, mean arterial pressure, pulse rate, respiratory rate, and dyspnea (P values: .012, .048, <.001, <.001, and .012, respectively). The results of our study support the benefit of using helium:oxygen adjunct with noninvasive positive-pressure ventilation in patients exposed to SM with acute respiratory decompensation.

  2. 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.

  3. 46 CFR 111.33-9 - Ventilation exhaust.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-9 Ventilation exhaust. The exhaust of each forced-air semiconductor rectifier system must: (a) Terminate in a location other than a hazardous...

  4. Randomised controlled trial of respiratory system compliance measurements in mechanically ventilated neonates

    PubMed Central

    Stenson, B.; Glover, R.; Wilkie, R.; Laing, I.; Tarnow-Mordi, W.

    1998-01-01

    AIM—To determine whether outcomes of neonatal mechanical ventilation could be improved by regular pulmonary function testing.
METHODS—Two hundred and forty five neonates, without immediately life threatening congenital malformations, were mechanically ventilated in the newborn period. Infants were randomly allocated to conventional clinical management (control group) or conventional management supplemented by regular measurements of static respiratory system compliance, using the single breath technique, with standardised management advice based on the results.
RESULTS—Fifty five (45%) infants in each group experienced one or more adverse outcomes. The median (quartile) durations of ventilation and oxygen supplementation were 5 (2-12) and 6 (2-34) days for the control group, and 4 (2-9) and 6 (3-36) days for the experimental group (not significant). On post-hoc secondary analysis, control group survivors were ventilated for 1269 days with a median (quartile) of 5 (2-13) days, and experimental group survivors were ventilated for 775 days with a median (quartile) duration of 3 (2-8) days (p=0.03).
CONCLUSIONS—Although primary analysis did not show any substantial benefit associated with regular measurement of static respiratory system compliance, this may reflect a type II error, and a moderate benefit has not been excluded. Larger studies are required to establish the value of on-line monitoring techniques now available with neonatal ventilators.

 PMID:9536834

  5. Reducing patients’ exposures to asthma and allergy triggers in their homes: an evaluation of effectiveness of grades of forced air ventilation filters

    PubMed Central

    Minegishi, Taeko; Allen, Joseph G.; McCarthy, John F.; Spengler, John D.; MacIntosh, David L.

    2014-01-01

    Objective Many interventions to reduce allergen levels in the home are recommended to asthma and allergy patients. One that is readily available and can be highly effective is the use of high performing filters in forced air ventilation systems. Methods We conducted a modeling analysis of the effectiveness of filter-based interventions in the home to reduce airborne asthma and allergy triggers. This work used “each pass removal efficiency” applied to health-relevant size fractions of particles to assess filter performance. We assessed effectiveness for key allergy and asthma triggers based on applicable particle sizes for cat allergen, indoor and outdoor sources of particles <2.5 µm in diameter (PM2.5), and airborne influenza and rhinovirus. Results Our analysis finds that higher performing filters can have significant impacts on indoor particle pollutant levels. Filters with removal efficiencies of >70% for cat dander particles, fine particulate matter (PM2.5) and respiratory virus can lower concentrations of those asthma triggers and allergens in indoor air of the home by >50%. Very high removal efficiency filters, such as those rated a 16 on the nationally recognized Minimum Efficiency Removal Value (MERV) rating system, tend to be only marginally more effective than MERV12 or 13 rated filters. Conclusions The results of this analysis indicate that use of a MERV12 or higher performing air filter in home ventilation systems can effectively reduce indoor levels of these common asthma and allergy triggers. These reductions in airborne allergens in turn may help reduce allergy and asthma symptoms, especially if employed in conjunction with other environmental management measures recommended for allergy and asthma patients. PMID:24555523

  6. Assessment of the impact of dipped guideways on urban rail transit systems: Ventilation and safety requirements

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The ventilation and fire safety requirements for subway tunnels with dipped profiles between stations as compared to subway tunnels with level profiles were evaluated. This evaluation is based upon computer simulations of a train fire emergency condition. Each of the tunnel configurations evaluated was developed from characteristics that are representative of modern transit systems. The results of the study indicate that: (1) The level tunnel system required about 10% more station cooling than dipped tunnel systems in order to meet design requirements; and (2) The emergency ventilation requirements are greater with dipped tunnel systems than with level tunnel systems.

  7. An evaluation of a local exhaust ventilation control system for a foundry casting-cleaning operation.

    PubMed

    Gressel, M G

    1997-05-01

    A study was conducted to evaluate the effectiveness of a local exhaust ventilation system for a foundry casting-cleaning operation in which a worker cleaned gray iron castings using a variety of handheld chipping and grinding tools. The operation originally had an exhaust system consisting only of an exhaust duct terminating approximately 1 m (3 ft) above the floor and 2 m (6 ft) from the casting-cleaning workstation. An earlier evaluation of this original control system found time-weighted average exposures to respirable silica ranging from 124 to 160 micrograms/m3. The local exhaust ventilation system evaluated in this present study consisted of a downdraft booth outfitted with a turntable for manipulating the castings. The modified local exhaust ventilation system was installed at this facility and connected to the existing plant exhaust ventilation system through the original ductwork. A direct-reading instrument was used to measure the operator's respirable aerosol exposure concentrations during a single day both before and after the installation of the new workstation. The same worker was sampled both times. The operator's activities were recorded on videotape so that the exposures associated with the various tools could be determined. While day-to-day variability could not be accounted for, depending on the type of tool used the local exhaust ventilation system reduced exposures by 59 to 79% during casting cleaning by the sampled worker when compared with the original configuration. These reductions were statistically significant.

  8. HVAC System Automatic Controls and Indoor Air Quality in Schools. Technical Bulletin.

    ERIC Educational Resources Information Center

    Wheeler, Arthur E.

    Fans, motors, coils, and other control components enable a heating, ventilating, and air-conditioning (HVAC) system to function smoothly. An explanation of these control components and how they make school HVAC systems work is provided. Different systems may be compared by counting the number of controlled devices that are required. Control…

  9. Selecting HVAC Systems for Schools To Balance the Needs for Indoor Air Quality, Energy Conservation and Maintenance. Technical Bulletin.

    ERIC Educational Resources Information Center

    Wheeler, Arthur E.; Kunz, Walter S., Jr.

    Although poor air quality in a school can have multiple causes, the heating, ventilating, and air-conditioning (HVAC) system plays a major role. Suggestions that architects, facilities managers, school board members, and administrators can use in selecting HVAC systems are discussed. Focus is on the performance criteria for classroom systems, and…

  10. 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.

  11. Reduction of nanoparticle exposure to welding aerosols by modification of the ventilation system in a workplace

    NASA Astrophysics Data System (ADS)

    Lee, Myong-Hwa; McClellan, William J.; Candela, Joe; Andrews, Dan; Biswas, Pratim

    2007-01-01

    Nanometer particle size distributions were measured in booths with two different ventilation patterns in an occupational environment with welding operations underway. The measurements were used to illustrate the impact of change of ventilation methods (existing - with ventilation ducts located at the top, modified - with ventilation ducts located below the weld bench) on the aerosol size distributions at different locations: close to the weld, in the vicinity of the welder's face, and in the exhaust duct. Particle number concentrations measured in the vicinity of the welder's face (mask) during a horizontal standard arc welding process in a booth with ventilation at the top was in the range of 7.78×105 particles cm-3 with a geometric mean size of 181 nm and geometric standard deviation of 1.8. This reduced to 1.48×104 particles cm-3 in the vicinity of the welder's face with the modified ventilation system. The clearance of the welding aerosol was also faster in the modified booth (6 min compared to 11 min in a conventional booth). Particles were collected in the booth for the various test conditions, and analyzed to determine their composition and morphology. The particles were composed of hazardous heavy metals such as manganese, chromium and nickel, and had varying morphologies.

  12. Decommissioning of Active Ventilation Systems in a Nuclear R and D Facility to Prepare for Building Demolition (Whiteshell Laboratories Decommissioning Project, Canada) - 13073

    SciTech Connect

    Wilcox, Brian; May, Doug; Howlett, Don; Bilinsky, Dennis

    2013-07-01

    Whiteshell Laboratories (WL) is a nuclear research establishment owned by the Canadian government and operated by Atomic Energy of Canada Limited (AECL) since the early 1960's. WL is currently under a decommissioning license and the mandate is to remediate the nuclear legacy liabilities in a safe and cost effective manner. The WL Project is the first major nuclear decommissioning project in Canada. A major initiative underway is to decommission and demolish the main R and D Laboratory complex. The Building 300 R and D complex was constructed to accommodate laboratories and offices which were mainly used for research and development associated with organic-cooled reactors, nuclear fuel waste management, reactor safety, advanced fuel cycles and other applications of nuclear energy. Building 300 is a three storey structure of approximately 16,000 m{sup 2}. In order to proceed with building demolition, the contaminated systems inside the building have to be characterized, removed, and the waste managed. There is a significant focus on volume reduction of radioactive waste for the WL project. The active ventilation system is one of the significant contaminated systems in Building 300 that requires decommissioning and removal. The active ventilation system was designed to manage hazardous fumes and radioactivity from ventilation devices (e.g., fume hoods, snorkels and glove boxes) and to prevent the escape of airborne hazardous material outside of the laboratory boundary in the event of an upset condition. The system includes over 200 ventilation devices and 32 active exhaust fan units and high efficiency particulate air (HEPA) filters. The strategy to remove the ventilation system was to work from the laboratory end back to the fan/filter system. Each ventilation duct was radiologically characterized. Fogging was used to minimize loose contamination. Sections of the duct were removed by various cutting methods and bagged for temporary storage prior to disposition

  13. VENTILATION MODEL REPORT

    SciTech Connect

    V. Chipman

    2002-10-31

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their postclosure analyses.

  14. Advanced air revitalization system testing

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; Hallick, T. M.; Schubert, F. H.

    1983-01-01

    A previously developed experimental air revitalization system was tested cyclically and parametrically. One-button startup without manual interventions; extension by 1350 hours of tests with the system; capability for varying process air carbon dioxide partial pressure and humidity and coolant source for simulation of realistic space vehicle interfaces; dynamic system performance response on the interaction of the electrochemical depolarized carbon dioxide concentrator, the Sabatier carbon dioxide reduction subsystem, and the static feed water electrolysis oxygen generation subsystem, the carbon dioxide concentrator module with unitized core technology for the liquid cooled cell; and a preliminary design for a regenerative air revitalization system for the space station are discussed.

  15. Rethinking hospital general ward ventilation design using computational fluid dynamics.

    PubMed

    Yam, R; Yuen, P L; Yung, R; Choy, T

    2011-01-01

    Indoor ventilation with good air quality control minimises the spread of airborne respiratory and other infections in hospitals. This article considers the role of ventilation in preventing and controlling infection in hospital general wards and identifies a simple and cost-effective ventilation design capable of reducing the chances of cross-infection. Computational fluid dynamic (CFD) analysis is used to simulate and compare the removal of microbes using a number of different ventilation systems. Instead of the conventional corridor air return arrangement used in most general wards, air return is rearranged so that ventilation is controlled from inside the ward cubicle. In addition to boosting the air ventilation rate, the CFD results reveal that ventilation performance and the removal of microbes can be significantly improved. These improvements are capable of matching the standards maintained in a properly constructed isolation room, though at much lower cost. It is recommended that the newly identified ventilation parameters be widely adopted in the design of new hospital general wards to minimise cross-infection. The proposed ventilation system can also be retrofitted in existing hospital general wards with far less disruption and cost than a full-scale refurbishment.

  16. Methane emissions and airflow patterns along longwall faces and through bleeder ventilation systems

    PubMed Central

    Schatzel, Steven J.; Dougherty, Heather N.

    2015-01-01

    The National Institute for Occupational Safety and Health (NIOSH) conducted an investigation of longwall face and bleeder ventilation systems using tracer gas experiments and computer network ventilation. The condition of gateroad entries, along with the caved material’s permeability and porosity changes as the longwall face advances, determine the resistance of the airflow pathways within the longwall’s worked-out area of the bleeder system. A series of field evaluations were conducted on a four-panel longwall district. Tracer gas was released at the mouth of the longwall section or on the longwall face and sampled at various locations in the gateroads inby the shield line. Measurements of arrival times and concentrations defined airflow/gas movements for the active/completed panels and the bleeder system, providing real field data to delineate these pathways. Results showed a sustained ability of the bleeder system to ventilate the longwall tailgate corner as the panels retreated. PMID:26925166

  17. Evaluation of AY/AZ tank farm ventilation system during aging waste retrieval operations

    SciTech Connect

    Wong, J.J.; Waters, E.D.

    1995-01-01

    Waste Management is currently planning to demonstrate mobilization of radioactive waste sludges in Tank 101-AZ beginning in October 1991. The retrieval system being designed will utilize mixer pumps that generate high-velocity, high-volume submerged liquid jets to mobilize settled solids. There is concern that these jets may also generate radioactive aerosols, some of which may be carried into the tank Ventilation system. The purpose of this study is to determine if the current AY/AZ ventilation system or the proposed ventilation system upgrade (Project W-030) will provide adequate deentrainment of liquid and solid aerosols during mixer pump operations, or if the radioactive aerosols will overload the HEPA filters.

  18. Household Ventilation May Reduce Effects of Indoor Air Pollutants for Prevention of Lung Cancer: A Case-Control Study in a Chinese Population

    PubMed Central

    Han, Ren-Qiang; Zhang, Xiao-Feng; Wang, Xu-Shan; Liu, Ai-Ming; Zhou, Jin-Yi; Lu, Qing-Yi; Kim, Claire H.; Mu, Lina; Zhang, Zuo-Feng; Zhao, Jin-Kou

    2014-01-01

    Background Although the International Agency for Research on Cancer (IARC) has classified various indoor air pollutants as carcinogenic to humans, few studies evaluated the role of household ventilation in reducing the impact of indoor air pollutants on lung cancer risk. Objectives To explore the association between household ventilation and lung cancer. Methods A population-based case-control study was conducted in a Chinese population from 2003 to 2010. Epidemiologic and household ventilation data were collected using a standardized questionnaire. Unconditional logistic regression was employed to estimate adjusted odds ratios (ORadj) and their 95% confidence intervals (CI). Results Among 1,424 lung cancer cases and 4,543 healthy controls, inverse associations were observed for good ventilation in the kitchen (ORadj = 0.86, 95% CI: 0.75, 0.98), bedroom (ORadj = 0.90, 95% CI: 0.79, 1.03), and both kitchen and bedroom (ORadj = 0.87, 95% CI: 0.75, 1.00). Stratified analyses showed lung cancer inversely associated with good ventilation among active smokers (ORadj = 0.85, 95% CI: 0.72, 1.00), secondhand smokers at home (ORadj = 0.77, 95% CI: 0.63, 0.94), and those exposed to high-temperature cooking oil fumes (ORadj = 0.82, 95% CI: 0.68, 0.99). Additive interactions were found between household ventilation and secondhand smoke at home as well as number of household pollutant sources. Conclusions A protective association was observed between good ventilation of households and lung cancer, most likely through the reduction of exposure to indoor air pollutants, indicating ventilation may serve as one of the preventive measures for lung cancer, in addition to tobacco cessation. PMID:25019554

  19. Air ejector augmented compressed air energy storage system

    DOEpatents

    Ahrens, F.W.; Kartsounes, G.T.

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  20. Air ejector augmented compressed air energy storage system

    DOEpatents

    Ahrens, Frederick W.; Kartsounes, George T.

    1980-01-01

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air pressure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  1. Procedures and Standards for Residential Ventilation System Commissioning: An Annotated Bibliography

    SciTech Connect

    Stratton, J. Chris; Wray, Craig P.

    2013-04-01

    Beginning with the 2008 version of Title 24, new homes in California must comply with ANSI/ASHRAE Standard 62.2-2007 requirements for residential ventilation. Where installed, the limited data available indicate that mechanical ventilation systems do not always perform optimally or even as many codes and forecasts predict. Commissioning such systems when they are installed or during subsequent building retrofits is a step towards eliminating deficiencies and optimizing the tradeoff between energy use and acceptable IAQ. Work funded by the California Energy Commission about a decade ago at Berkeley Lab documented procedures for residential commissioning, but did not focus on ventilation systems. Since then, standards and approaches for commissioning ventilation systems have been an active area of work in Europe. This report describes our efforts to collect new literature on commissioning procedures and to identify information that can be used to support the future development of residential-ventilation-specific procedures and standards. We recommend that a standardized commissioning process and a commissioning guide for practitioners be developed, along with a combined energy and IAQ benefit assessment standard and tool, and a diagnostic guide for estimating continuous pollutant emission rates of concern in residences (including a database that lists emission test data for commercially-available labeled products).

  2. Control Strategies for Reducing Heating, Ventilating, and Air Conditioning (HVAC) Energy Consumption in Single Buildings.

    DTIC Science & Technology

    1983-03-01

    deadband is increased to 5°F. Zone-mixing dampers will then begin to supply warm air when the zone temperature drops to 70.5°F and will supply the maximum...diagnostic capability, and interface to EMCS systems. Since many types of centrifugal and reciprocating compressors rely on oil in the refrigerant for...Electrically powered chiller operating cost (Ref 8) .. ......... 5.4 V/kW-hr Oil -fired, hot water boiler operating cost (Ref 8) .. ......... 6.96 $/MBtu

  3. The effect of low ventilation rate with elevated bioeffluent concentration on work performance, perceived indoor air quality and health symptoms.

    PubMed

    Maula, Henna; Hongisto, Valtteri; Naatula, Viivi; Haapakangas, Annu; Koskela, Hannu

    2017-04-05

    The aim of this laboratory experiment was to study the effects of ventilation rate, and related changes in air quality, predominantly bioeffluents, on work performance, perceived indoor air quality and health symptoms in a typical conditions of modern open-plan office with low material and equipment emissions. In Condition A, outdoor air flow rate of 28.2 l/s person (CO2 level 540 ppm) was applied and in Condition B, outdoor air flow rate was 2.3 l/s person (CO2 level 2260 ppm). CO2 concentration level was used as an indicator of bioeffluents. Performance was measured with seven different tasks which measure different cognitive processes. Thirty-six subjects participated in the experiment. The exposure time was 4 hours. Condition B had a weak negative effect on performance only in the information retrieval tasks. Condition B increased slightly subjective workload and perceived fatigue. No effects on health symptoms were found. The intensity of symptoms was low in both conditions. The experimental condition had an effect on perceived air quality and observed odour intensity only in the beginning of the session. Although the room temperature was controlled in both conditions, the heat was perceived to impair the performance more in Condition B. This article is protected by copyright. All rights reserved.

  4. Ventilation and ventilators.

    PubMed

    Hayes, B

    1982-01-01

    The history of ventilation is reviewed briefly and recent developments in techniques of ventilation are discussed. Operating features of ventilators have changed in the past few years, partly as the result of clinical progress; yet, technology appears to have outstripped the clinician's ability to harness it most effectively. Clinical discipline and training of medical staff in the use of ventilators could be improved. The future is promising if clinician and designer can work together closely. Ergonomics of ventilators and their controls and the provision of alarms need special attention. Microprocessors are likely to feature prominently in the next generation of designs.

  5. A perfluorochemical loss/restoration (L/R) system for tidal liquid ventilation.

    PubMed

    Libros, R; Philips, C M; Wolfson, M R; Shaffer, T H

    2000-01-01

    Tidal liquid ventilation is the transport of dissolved respiratory gases via volume exchange of perfluorochemical (PFC) liquid to and from the PFC-filled lung. All gas-liquid surface tension is eliminated, increasing compliance and providing lung protection due to lower inflation pressures. Tidal liquid ventilation is achieved by cycling fluid from a reservoir to and from the lung by a ventilator. Current approaches are microprocessor-based with feedback control. During inspiration, warmed oxygenated PFC liquid is pumped from a fluid reservoir/gas exchanger into the lung. PFC fluid is conserved by condensing (60-80% efficiency) vapor in the expired gas. A feedback-control system was developed to automatically replace PFC lost due to condenser inefficiency. This loss/restoration (L/R) system consists of a PFC-vapor thermal detector (+/- 2.5%), pneumatics, amplifiers, a gas flow detector (+/- 1%), a PFC pump (+/- 5%), and a controller. Gravimetric studies of perflubron loss from a flask due to evaporation were compared with experimental L/R results and found to be within +/- 1.4%. In addition, when L/R studies were conducted with a previously reported liquid ventilation system over a four-hour period, the L/R system maintained system perflubron volume to within +/- 1% of prime volume and 11.5% of replacement volume, and the difference between experimental PFC loss and that of the L/R system was 1.8 mL/hr. These studies suggest that the PFC L/R system may have significant economic (appropriate dosing for PFC loss) as well as physiologic (maintenance of PFC inventory in the lungs and liquid ventilator) impact on liquid ventilation procedures.

  6. Air Pollution Surveillance Systems

    ERIC Educational Resources Information Center

    Morgan, George B.; And Others

    1970-01-01

    Describes atmospheric data monitoring as part of total airpollution control effort. Summarizes types of gaseous, liquid and solid pollutants and their sources; contrast between urban and rural environmental air quality; instrumentation to identify pollutants; and anticipated new non-wet chemical physical and physiochemical techniques tor cetection…

  7. Ventilation Model and Analysis Report

    SciTech Connect

    V. Chipman

    2003-07-18

    This model and analysis report develops, validates, and implements a conceptual model for heat transfer in and around a ventilated emplacement drift. This conceptual model includes thermal radiation between the waste package and the drift wall, convection from the waste package and drift wall surfaces into the flowing air, and conduction in the surrounding host rock. These heat transfer processes are coupled and vary both temporally and spatially, so numerical and analytical methods are used to implement the mathematical equations which describe the conceptual model. These numerical and analytical methods predict the transient response of the system, at the drift scale, in terms of spatially varying temperatures and ventilation efficiencies. The ventilation efficiency describes the effectiveness of the ventilation process in removing radionuclide decay heat from the drift environment. An alternative conceptual model is also developed which evaluates the influence of water and water vapor mass transport on the ventilation efficiency. These effects are described using analytical methods which bound the contribution of latent heat to the system, quantify the effects of varying degrees of host rock saturation (and hence host rock thermal conductivity) on the ventilation efficiency, and evaluate the effects of vapor and enhanced vapor diffusion on the host rock thermal conductivity.

  8. Combined Heat, Air, Moisture, and Pollutants Transport in Building Environmental Systems

    NASA Astrophysics Data System (ADS)

    Zhang, Jianshun Jensen S.

    Combined heat, air, moisture and pollutants transport (CHAMP) exists across multi-scales of a building environmental system (BES): around the building, through the building shell/envelope, inside a multizone building, and in the micro-environments around occupants. This paper reviews previous work and presents a system model for simulating these transport processes and their impacts on indoor environmental quality. Components of the system model include a multizone network flow model for whole building, a room model for air and pollutant movement in ventilated spaces, a coupled heat, air, moisture, and pollutant transport model for building shell, an HVAC model for describing the dynamics of the heating, ventilating and air-conditioning (HVAC) system, and shared databases of weather conditions, transport properties of building materials, and volatile organic compounds (VOCs) emissions from building materials and furnishings. The interactions among the different components, and challenges in developing the CHAMP system model for intelligent control of BES are also discussed.

  9. Cleanup and Dismantling of Highly Contaminated Ventilation Systems Using Robotic Tools - 13162

    SciTech Connect

    Chambon, Frederic; CIZEL, Jean-Pierre

    2013-07-01

    The UP1 plant reprocessed nearly 20,000 tons of used natural uranium gas cooled reactor fuel coming from the first generation of civil nuclear reactors in France. Following operating incidents in the eighties, the ventilation system of the continuous dissolution line facility was shut down and replaced. Two types of remote controlled tool carriers were developed to perform the decontamination and dismantling operations of the highly contaminated ventilation duct network. The first one, a dedicated small robot, was designed from scratch to retrieve a thick powder deposit within a duct. The robot, managed and confined by two dedicated glove boxes, was equipped for intervention inside the ventilation duct and used for carrying various cleanup and inspection tools. The second type, consisting of robotic tools developed on the base of an industrial platform, was used for the clean-up and dismantling of the ventilation duct system. Depending on the type of work to be performed, on the shape constraints of the rooms and any equipment to be dismantled, different kinds of robotic tools were developed and installed on a Brokk 40 carrier. After more than ten years of ventilation duct D and D operations at the UP1 plant, a lot of experience was acquired about remote operations. The three main important lessons learned in terms of remote controlled operation are: characterizing the initial conditions as much as reasonably possible, performing non-radioactive full scale testing and making it as simple and modular as possible. (authors)

  10. ADMINISTRATIVE AND ENGINEERING CONTROLS FOR THE OPERATION OF VENTILATION SYSTEMS FOR UNDERGROUND RADIOACTIVE WASTE STORAGE TANKS

    SciTech Connect

    Wiersma, B.; Hansen, A.

    2013-11-13

    Liquid radioactive wastes from the Savannah River Site are stored in large underground carbon steel tanks. The majority of the waste is confined in double shell tanks, which have a primary shell, where the waste is stored, and a secondary shell, which creates an annular region between the two shells, that provides secondary containment and leak detection capabilities should leakage from the primary shell occur. Each of the DST is equipped with a purge ventilation system for the interior of the primary shell and annulus ventilation system for the secondary containment. Administrative flammability controls require continuous ventilation to remove hydrogen gas and other vapors from the waste tanks while preventing the release of radionuclides to the atmosphere. Should a leak from the primary to the annulus occur, the annulus ventilation would also serve this purpose. The functionality of the annulus ventilation is necessary to preserve the structural integrity of the primary shell and the secondary. An administrative corrosion control program is in place to ensure integrity of the tank. Given the critical functions of the purge and annulus ventilation systems, engineering controls are also necessary to ensure that the systems remain robust. The system consists of components that are constructed of metal (e.g., steel, stainless steel, aluminum, copper, etc.) and/or polymeric (polypropylene, polyethylene, silicone, polyurethane, etc.) materials. The performance of these materials in anticipated service environments (e.g., normal waste storage, waste removal, etc.) was evaluated. The most aggressive vapor space environment occurs during chemical cleaning of the residual heels by utilizing oxalic acid. The presence of NO{sub x} and mercury in the vapors generated from the process could potentially accelerate the degradation of aluminum, carbon steel, and copper. Once identified, the most susceptible materials were either replaced and/or plans for discontinuing operations

  11. A model-based decision support system for critiquing mechanical ventilation treatments.

    PubMed

    Tehrani, Fleur T; Abbasi, Soraya

    2012-06-01

    A computerized system for critiquing mechanical ventilation treatments is presented that can be used as an aide to the intensivist. The presented system is based on the physiological model of the subject's respiratory system. It uses modified versions of previously developed models of adult and neonatal respiratory systems to simulate the effects of different ventilator treatments on the patient's blood gases. The physiological models that have been used for research and teaching purposes by many researchers in the field include lungs, body tissue, and the brain tissue. The lung volume is continuously time-varying and the effects of shunt in the lung, changes in cardiac output and cerebral blood flow, and the arterial transport delays are included in the system. Evaluation tests were done on adult and neonate patients with different diagnoses. In both groups combined, the differences between the arterial partial pressures of CO(2) predicted by the system and the experimental values were 1.86 ± 1.6 mmHg (mean ± SD), and the differences between the predicted arterial hemoglobin oxygen saturation values, S(aO2), and the experimental values measured by using pulse oximetry, S(pO2), were 0.032 ± 0.02 (mean ± SD). The proposed system has the potential to be used alone or in combination with other decision support systems to set ventilation parameters and optimize treatment for patients on mechanical ventilation.

  12. [Comparison of volume preset and pressure preset ventilators during daytime nasal ventilation in chronic respiratory failure].

    PubMed

    Perrin, C; Wolter, P; Berthier, F; Tamisier, R; Jullien, V; Lemoigne, F; Blaive, B

    2001-02-01

    Both volume preset and pressure preset ventilators are available for domiciliary nasal ventilation. Owing to their technical characteristics, it has been suggested that impaired ventilatory mechanics might cause a drop in the tidal volume (Vt) delivered by pressure preset devices, thereby placing mechanical ventilation at risk of inefficacy. We have assessed two ventilator systems (one pressure preset and one volume preset) with regard to the tidal volume and end-tidal carbon dioxide tension (PetCO(2)) changes that may be achieved in a group of awake patients with stable chronic respiratory failure (CRF). Eleven patients with stable CRF were ventilated in the assist/control mode for two consecutive one-hour periods. One ventilator was tested each hour, in random order. The VIGIL'AIR(R) system was used to record Vt, Respiratory Rate (RR), and Inspiratory/Expiratory ratio (I/E). The deviation E (E=preset value - measured value) was calculated for each measurement. Changes in PetCO(2) and arterial oxygen saturation were determined respectively by a capnometer and a pulse oximeter. Comparison of the mean deviation of Vt calculated for the two ventilators revealed a difference in patients with chronic obstructive pulmonary disease (COPD). The deviation was greatest with the pressure preset ventilator (PPV), which gave mean measured values higher than the mean preset values. The same comparison failed to reveal any difference in restrictive CRF. Comparison of the volume preset and pressure preset ventilators for RR, I/E and PetCO(2) did not reveal any difference. Compared to the volume preset ventilator, the efficacy of PPV to ventilate is not affected by the restrictive or obstructive nature of CRF. Our results show that pressure-preset ventilator is an adequate alternative to the volume-preset device for daytime non invasive ventilation in chronic respiratory insufficiency.

  13. [Evaluation of a new nitric oxide delivery system during mechanical ventilation].

    PubMed

    Noguchi, T; Miyakawa, H; Mori, M; Kitano, T; Iwasaka, H; Oda, S; Taniguchi, K; Honda, N

    1994-07-01

    A new nitric oxide delivery and continuous monitoring system is described. During mechanical ventilation, this new system connected with Siemens Servo 900C ventilator was shown to be able to provide a constant inspired NO concentration (10-100 ppm) using chemiluminescence technique for NO analysis. Gas was analysed at the mixing chamber in front of the ventilator inlet and inspiratory tube connected with the soda-lime carbon-dioxide absorber. Both NO concentrations showed a good correlation (r = 0.99). The actual NO concentration from the NO supply cylinder was 1154 ppm and NO2 concentration was 14 ppm. In mongrel dogs, after 20 minutes of NO inhalation (10-100 ppm), the blood methemoglobin level reached a peak value of 2.2% starting from the pre-inhalation level of 0%. To optimize the safety of the clinical application of NO, its concentration should be measured continuously with chemiluminescence technique.

  14. Barriers to Improved Ventilation in Production Housing: Preprint

    SciTech Connect

    Barley, C. D.

    2002-04-01

    In addressing the goals of energy-efficiency and indoor air quality (IAQ) in homes, industry teams in the U.S. Department of Energy's Building America program are installing mechanical ventilation systems in tight homes.

  15. Cold air systems: Sleeping giant

    SciTech Connect

    MacCracken, C.D. )

    1994-04-01

    This article describes how cold air systems help owners increase the profits from their buildings by reducing electric costs and improving indoor air quality through lower relative humidity levels. Cold air distribution involves energy savings, cost savings, space savings, greater comfort, cleaner air, thermal storage, tighter ducting, coil redesign, lower relative humidities, retrofitting, and improved indoor air quality (IAQ). It opens a door for architects, engineers, owners, builders, environmentalists, retrofitters, designers, occupants, and manufacturers. Three things have held up cold air's usage: multiple fan-powered boxes that ate up the energy savings of primary fans. Cold air room diffusers that provided inadequate comfort. Condensation from ducts, boxes, and diffusers. Such problems have been largely eliminated through research and development by utilities and manufacturers. New cold air diffusers no longer need fan powered boxes. It has also been found that condensation is not a concern so long as the ducts are located in air conditioned space, such as drop ceilings or central risers, where relative humidity falls quickly during morning startup.

  16. Intermodule ventilation studies for the Space Station

    NASA Technical Reports Server (NTRS)

    Davis, Roy G.; Reuter, James L.

    1987-01-01

    This paper examines the ability of the Space Station intermodule ventilation system to maintain centralized control of CO2 removal and O2 supply. The resulting concentration gradients that will arise are calculated by assuming steady state, ideal gas, isothermal conditions, and perfect mixing of air within and between the pressurized elements. In order to estimate the degree of mixing actually obtained for a given ventilation scheme, a program has been developed based on a potential flow solution technique. Preliminary results from this study indicate that substantial short circuiting and recirculation air flow patterns could arise if a simple duct and diffuser air exchange method at the docking port interface were employed.

  17. Alaskan Air Defense and Early Warning Systems Clear Air ...

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

    Alaskan Air Defense and Early Warning Systems - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  18. 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.

  19. Examination of redirected continuous miner scrubber discharge configurations for exhaust face ventilation systems

    PubMed Central

    Organiscak, J.A.; Beck, T.W.

    2015-01-01

    The U.S. National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) has recently studied several redirected scrubber discharge configurations in its full-scale continuous miner gallery for both dust and gas control when using an exhaust face ventilation system. Dust and gas measurements around the continuous mining machine in the laboratory showed that the conventional scrubber discharge directed outby the face with a 12.2-m (40-ft) exhaust curtain setback appeared to be one of the better configurations for controlling dust and gas. Redirecting all the air toward the face equally up both sides of the machine increased the dust and gas concentrations around the machine. When all of the air was redirected toward the face on the off-curtain side of the machine, gas accumulations tended to be reduced at the face, at the expense of increased dust levels in the return and on the curtain side of the mining machine. A 6.1-m (20-ft) exhaust curtain setback without the scrubber operating resulted in the lowest dust levels around the continuous mining machine, but this configuration resulted in some of the highest levels of dust in the return and gas on the off-curtain side of the mining face. Two field studies showed some similarities to the laboratory findings, with elevated dust levels at the rear corners of the continuous miner when all of the scrubber exhaust was redirected toward the face either up the off-tubing side or equally up both sides of the mining machine. PMID:26251566

  20. Wireless Condition Monitoring and Maintenance for Rooftop Packaged Heating, Ventilation, and Air-Conditioning

    SciTech Connect

    Katipamula, Srinivas; Brambley, Michael R.

    2004-06-01

    Rooftop package air-conditioning and heat pumps, while representing over half of U.S. commercial-building cooling energy consumption, are some of the most neglected of building systems. They are often found with inoperable dampers, dirty/clogged filters and coils, incorrect refrigerant charges, failing compressors, failed fans, missing enclosure panels, un-calibrated controls, failed sensors, and other problems. Frequently, actual operating hours deviate considerably from intended (and assumed) schedules. Although there are no reliable estimates on what fraction of the units operate under degraded conditions and the energy inefficiencies associated with such operations, a range of savings from 10 to 30% are generally believed to be achievable by enhancing operation of these units. Potential national energy savings from proper operation range from 23 to 70 trillion Btus annually in the U.S. Since the cost associated with conventional monitoring and servicing is quite high, conventional monitoring is seldom done. Combinations of wireless sensing and data acquisition, monitoring tools, automated diagnostics and prognostics show considerable promise to help remedy this maintenance problem for package HVAC units and the underserved small commercial building sector in which they are predominantly installed. This paper characterizes the current problem with maintenance of packaged air conditioners and heat pumps, provides estimates of the total energy impacts of the problem, and describes a generic system in which these developing technologies are used to provide real-time condition monitoring for package HVAC units and their components. Costs with today's technology are provided and future costs are estimated, showing that benefits will greatly exceed costs in many cases particularly if low-cost wireless monitoring is used.

  1. Parametric instabilities of rotor-support systems with application to industrial ventilators

    NASA Technical Reports Server (NTRS)

    Parszewski, Z.; Krodkiemski, T.; Marynowski, K.

    1980-01-01

    Rotor support systems interaction with parametric excitation is considered for both unequal principal shaft stiffness (generators) and offset disc rotors (ventilators). Instability regions and types of instability are computed in the first case, and parametric resonances in the second case. Computed and experimental results are compared for laboratory machine models. A field case study of parametric vibrations in industrial ventilators is reported. Computed parametric resonances are confirmed in field measurements, and some industrial failures are explained. Also the dynamic influence and gyroscopic effect of supporting structures are shown and computed.

  2. AUTOPILOT-BT: a system for knowledge and model based mechanical ventilation.

    PubMed

    Lozano, S; Möller, K; Brendle, A; Gottlieb, D; Schumann, S; Stahl, C A; Guttmann, J

    2008-01-01

    A closed-loop system (AUTOPILOT-BT) for the control of mechanical ventilation was designed to: 1) autonomously achieve goals specified by the clinician, 2) optimize the ventilator settings with respect to the underlying disease and 3) automatically adapt to the individual properties and specific disease status of the patient. The current realization focuses on arterial oxygen saturation (SpO(2)), end-tidal CO(2) pressure (P(et)CO(2)), and positive end-expiratory pressure (PEEP) maximizing respiratory system compliance (C(rs)). The "AUTOPILOT-BT" incorporates two different knowledge sources: a fuzzy logic control reflecting expert knowledge and a mathematical model based system that provides individualized patient specific information. A first evaluation test with respect to desired end-tidal-CO(2)-level was accomplished using an experimental setup to simulate three different metabolic CO(2) production rates by means of a physical lung simulator. The outcome of ventilator settings made by the "AUTOPILOT-BT" system was compared to those produced by clinicians. The model based control system proved to be superior to the clinicians as well as to a pure fuzzy logic based control with respect to precision and required settling time into the optimal ventilation state.

  3. Ventilation and infiltration in high-rise apartment buildings

    SciTech Connect

    Diamond, R.C.; Feustel, H.E.; Dickerhoff, D.J.

    1996-03-01

    Air flow, air leakage measurements and numerical simulations were made on a 13-story apartment building to characterize the ventilation rates for the individual apartments. Parametric simulations were performed for specific conditions, e.g., height, orientation, outside temperature and wind speed. Our analysis of the air flow simulations suggest that the ventilation to the individual units varies considerably. With the mechanical ventilation system disabled and no wind, units at the lower level of the building have adequate ventilation only on days with high temperature differences, while units on higher floors have no ventilation at all. Units facing the windward side will be over-ventilated when the building experiences wind directions between west and north. At the same time, leeward apartments did not experience any fresh air-because, in these cases, air flows enter the apartments from the corridor and exit through the exhaust shafts and the cracks in the facade. Even with the mechanical ventilation system operating, we found wide variation in the air flows to the individual apartments. In addition to the specific case presented here, these findings have more general implications for energy retrofits and health and comfort of occupants in high-rise apartment buildings.

  4. Ventilator-Related Adverse Events: A Taxonomy and Findings From 3 Incident Reporting Systems

    PubMed Central

    Pham, Julius Cuong; Williams, Tamara L; Sparnon, Erin M; Cillie, Tam K; Scharen, Hilda F; Marella, William M

    2016-01-01

    BACKGROUND: In 2009, researchers from Johns Hopkins University's Armstrong Institute for Patient Safety and Quality; public agencies, including the FDA; and private partners, including the Emergency Care Research Institute and the University HealthSystem Consortium (UHC) Safety Intelligence Patient Safety Organization, sought to form a public-private partnership for the promotion of patient safety (P5S) to advance patient safety through voluntary partnerships. The study objective was to test the concept of the P5S to advance our understanding of safety issues related to ventilator events, to develop a common classification system for categorizing adverse events related to mechanical ventilators, and to perform a comparison of adverse events across different adverse event reporting systems. METHODS: We performed a cross-sectional analysis of ventilator-related adverse events reported in 2012 from the following incident reporting systems: the Pennsylvania Patient Safety Authority's Patient Safety Reporting System, UHC's Safety Intelligence Patient Safety Organization database, and the FDA's Manufacturer and User Facility Device Experience database. Once each organization had its dataset of ventilator-related adverse events, reviewers read the narrative descriptions of each event and classified it according to the developed common taxonomy. RESULTS: A Pennsylvania Patient Safety Authority, FDA, and UHC search provided 252, 274, and 700 relevant reports, respectively. The 3 event types most commonly reported to the UHC and the Pennsylvania Patient Safety Authority's Patient Safety Reporting System databases were airway/breathing circuit issue, human factor issues, and ventilator malfunction events. The top 3 event types reported to the FDA were ventilator malfunction, power source issue, and alarm failure. CONCLUSIONS: Overall, we found that (1) through the development of a common taxonomy, adverse events from 3 reporting systems can be evaluated, (2) the types of

  5. Positive-Pressure Ventilator Systems at High Altitude: A Preliminary Study.

    DTIC Science & Technology

    1986-06-01

    Respiratory Distress Syndrome ( ARDS ), which is...of using mechanical ventilator systems with ARDA patients in high-altitude environments. DTIC A1 - a ADULT RESPIRATORY DISTRESS SYNDROME ARDS has been...capillary pressure) pulmonary edema and acute respiratory failure. The clinical physiology of severe ARDS is characterized by three phenomena: 1)

  6. Measuring Airflow in Local Exhaust Ventilation Systems. Module 23. Vocational Education Training in Environmental Sciences.

    ERIC Educational Resources Information Center

    Consumer Dynamics Inc., Rockville, MD.

    This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on measuring airflow in local exhaust ventilation systems. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) naming each…

  7. A survey and critical review of the literature on indoor air quality, ventilation and health symptoms in schools

    SciTech Connect

    Daisey, J.M.; Angell, W.J.

    1998-03-01

    A survey and critical review were undertaken of existing published literature and reports on indoor air quality (IAQ), ventilation, and IAQ- and building-related health problems in schools, including California schools. Over 450 relevant publications were obtained and reviewed, including papers published in the archival peer-reviewed scientific literature, proceedings of scientific meetings, government reports, 77 NIOSH Health Hazard Evaluation Reports (HHER) and 70 reports on investigations of problem schools in California. Most of the reviewed literature was for complaint or problem schools. The types of health symptoms reported in schools were very similar to those defined as sick building syndrome (SBS) symptoms, although this may be due, at least in part, to the type of health symptom questionnaires used. Some of the symptoms, e.g., wheezing, are indicative of asthma. In the studies in which complaint and noncomplaint buildings or areas were compared, complaint buildings generally had higher rates of health symptoms.

  8. A Survey and Critical Review of the Literature on Indoor Air Quality, Ventilation and Health Symptoms in Schools. IEQ Strategies[TM].

    ERIC Educational Resources Information Center

    Daisey, Joan M.; Angell, William J.

    This report presents detailed results from a survey and critical review of existing published literature and reports on indoor air quality (IAQ), ventilation, and IAQ- and building-related health problems in schools, particularly California schools. The findings: (1) identify the most commonly reported building-related health symtoms involving…

  9. [Evaluation of patient-ventilator synchrony of three new types of ventilators with pressure sunnort ventilation mode].

    PubMed

    Zhou, Juan; Wu, Hao; Cao, Desen

    2014-08-01

    Pressure-support ventilation (PSV) is a form of important ventilation mode. Patient-ventilator synchrony of pressure support ventilation can be divided into inspiration-triggered and expiration-triggered ones. Whether the ventilator can track the patient's inspiration and expiration very well or not is an important evaluating item of the performance of the ventilator. The ventilator should response to the patient's inspiration effort on time and deliver the air flow to the patient under various conditions, such as different patient's lung types and inspiration effort, etc. Similarly, the ventilator should be able to response to the patient's expiration action, and to decrease the patient lung's internal pressure rapidly. Using the Active Servo Lung (ASL5000) respiratory simulation system, we evaluated the spontaneous breathing of PSV mode on E5, Servo i and Evital XL. The following parameters, the delay time before flow to the patient starts once the trigger variable signaling the start of inspiration, the lowest inspiratory airway pressure generated prior to the initiation of PSV, etc. were measured.

  10. Solar ventilation and tempering

    NASA Astrophysics Data System (ADS)

    Adámek, Karel; Pavlů, Miloš; Bandouch, Milan

    2014-08-01

    The paper presents basic information about solar panels, designed, realized and used for solar ventilation of rooms. Used method of numerical flow simulation gives good overview about warming and flowing of the air in several kinds of realized panels (window, facade, chimney). Yearlong measurements give a good base for calculations of economic return of invested capital. The operation of the system in transient period (spring, autumn) prolongs the period without classical heating of the room or building, in winter the classical heating is supported. In the summer period the system, furnished with chimney, can exhaust inner warm air together with necessary cooling of the system by gravity circulation, only. System needs not any invoiced energy source; it is supplied entirely by solar energy. Large building systems are supported by classical electric fan respectively.

  11. Air support facilities. [interface between air and surface transportation systems

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Airports are discussed in terms of the interface between the ground and air for transportation systems. The classification systems, design, facilities, administration, and operations of airports are described.

  12. Flow-Field Characteristics of High-Temperature Annular Buoyant Jets and Their Development Laws Influenced by Ventilation System

    PubMed Central

    Liu, Jiaping; Wang, Hai; Liu, Qiuhan

    2013-01-01

    The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity and temperature decay, reattachment position, cross-section diameter, volumetric flow rate, and velocity field characteristics with different pressures at the exhaust hood inlet. The results showed that when the ratio of outer diameter to inner diameter of the annulus was smaller than 5/2, the flow-field characteristics had significant difference compared to circular buoyant jets with the same outer diameter. For similar diameter ratios, reattachment in this paper occurred further downstream in contrast to previous study. Besides, the development laws of volumetric flow rate and cross-section diameter were given with different initial parameters. In addition, through analyzing air distribution characteristics under the coupling effect of high-temperature annular buoyant jets and ventilation system, it could be found that the position where maximum axial velocity occurred was changing gradually when the pressure at the exhaust hood inlet changed from 0 Pa to −5 Pa. PMID:24000278

  13. Flow-field characteristics of high-temperature annular buoyant jets and their development laws influenced by ventilation system.

    PubMed

    Wang, Yi; Huang, Yanqiu; Liu, Jiaping; Wang, Hai; Liu, Qiuhan

    2013-01-01

    The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity and temperature decay, reattachment position, cross-section diameter, volumetric flow rate, and velocity field characteristics with different pressures at the exhaust hood inlet. The results showed that when the ratio of outer diameter to inner diameter of the annulus was smaller than 5/2, the flow-field characteristics had significant difference compared to circular buoyant jets with the same outer diameter. For similar diameter ratios, reattachment in this paper occurred further downstream in contrast to previous study. Besides, the development laws of volumetric flow rate and cross-section diameter were given with different initial parameters. In addition, through analyzing air distribution characteristics under the coupling effect of high-temperature annular buoyant jets and ventilation system, it could be found that the position where maximum axial velocity occurred was changing gradually when the pressure at the exhaust hood inlet changed from 0 Pa to -5 Pa.

  14. Prototype Systems for Measuring Outdoor Air Intake Rates in Rooftop Air Handlers

    SciTech Connect

    Fisk, William J.; Chan, Wanyu R.; Hotchi, Toshifumi

    2015-01-01

    The widespread absence of systems for real-time measurement and feedback control, of minimum outdoor air intake rates in HVAC systems contributes to the poor control of ventilation rates in commercial buildings. Ventilation rates affect building energy consumption and influence occupant health. The project designed fabricated and tested four prototypes of systems for measuring rates of outdoor air intake into roof top air handlers. All prototypes met the ±20% accuracy target at low wind speeds, with all prototypes accurate within approximately ±10% after application of calibration equations. One prototype met the accuracy target without a calibration. With two of four prototype measurement systems, there was no evidence that wind speed or direction affected accuracy; however, winds speeds were generally below usually 3.5 m s-1 (12.6 km h-1) and further testing is desirable. The airflow resistance of the prototypes was generally less than 35 Pa at maximum RTU air flow rates. A pressure drop of this magnitude will increase fan energy consumption by approximately 4%. The project did not have resources necessary to estimate costs of mass produced systems. The retail cost of components and materials used to construct prototypes ranged from approximately $1,200 to $1,700. The test data indicate that the basic designs developed in this project, particularly the designs of two of the prototypes, have considerable merit. Further design refinement, testing, and cost analysis would be necessary to fully assess commercial potential. The designs and test results will be communicated to the HVAC manufacturing community.

  15. 46 CFR 108.437 - Pipe sizes and discharge rates for enclosed ventilation systems for rotating electrical equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Pipe sizes and discharge rates for enclosed ventilation... HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing... enclosed ventilation systems for rotating electrical equipment. (a) The minimum pipe size for the...

  16. 46 CFR 108.437 - Pipe sizes and discharge rates for enclosed ventilation systems for rotating electrical equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Pipe sizes and discharge rates for enclosed ventilation... HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing... enclosed ventilation systems for rotating electrical equipment. (a) The minimum pipe size for the...

  17. 46 CFR 108.437 - Pipe sizes and discharge rates for enclosed ventilation systems for rotating electrical equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Pipe sizes and discharge rates for enclosed ventilation... HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing... enclosed ventilation systems for rotating electrical equipment. (a) The minimum pipe size for the...

  18. Guide to Home Ventilation

    SciTech Connect

    2010-10-01

    A fact sheet from the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy: Ventilation refers to the exchange of indoor and outdoor air. Without proper ventilation, an otherwise insulated and airtight house will seal in harmful pollutants, such as carbon monoxide, and moisture that can damage a house.

  19. The effect of spontaneous breathing on systemic interleukin-6 during ventilator weaning.

    PubMed

    Sellarés, J; Loureiro, H; Ferrer, M; Amaro, R; Farré, R; Torres, A

    2012-03-01

    During the weaning process, spontaneous breathing trials (SBTs) involve cardiopulmonary stress for ventilated patients. As interleukin (IL)-6 is a major modulator of the stress response, we hypothesised that systemic IL-6 increases during a SBT and that this increase is more evident in SBT failure. 49 SBTs of 30-min duration were performed on different mechanically ventilated patients, and classified as SBT failure or success. Blood samples were drawn before and at the end of the SBT. An additional sample was drawn 24 h later in a subset of patients (n = 39). Serum IL-6 levels and other inflammatory mediators commonly associated with stress were determined. IL-6 levels increased from mechanical ventilation to spontaneous breathing in all patients (p = 0.02) and in the chronic obstructive pulmonary disease (COPD) population (p = 0.05) with SBT failure compared with success, but not in non-COPD patients (p = 0.12). After 24 h of SBT stress, IL-6 levels decreased in patients with SBT failure (under mechanical ventilation at that point) (p = 0.02) and those with weaning success (p = 0.04). No changes were observed in the remaining inflammatory mediators. Systemic IL-6 increases during a 30-min, failed SBT, especially in COPD patients. Future studies may corroborate the different IL-6 responses among different populations who initiate weaning, together with the potential clinical implications.

  20. 41 CFR 102-74.195 - What ventilation policy must Federal agencies follow?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... provide ventilation in accordance with ASHRAE Standard 62, Ventilation for Acceptable Indoor Air Quality... ventilation up to current standards. ASHRAE Standard 62 is available from ASHRAE Publications Sales,...

  1. Energy and cost associated with ventilating office buildings in a tropical climate.

    PubMed

    Rim, Donghyun; Schiavon, Stefano; Nazaroff, William W

    2015-01-01

    Providing sufficient amounts of outdoor air to occupants is a critical building function for supporting occupant health, well-being and productivity. In tropical climates, high ventilation rates require substantial amounts of energy to cool and dehumidify supply air. This study evaluates the energy consumption and associated cost for thermally conditioning outdoor air provided for building ventilation in tropical climates, considering Singapore as an example locale. We investigated the influence on energy consumption and cost of the following factors: outdoor air temperature and humidity, ventilation rate (L/s per person), indoor air temperature and humidity, air conditioning system coefficient of performance (COP), and cost of electricity. Results show that dehumidification of outdoor air accounts for more than 80% of the energy needed for building ventilation in Singapore's tropical climate. Improved system performance and/or a small increase in the indoor temperature set point would permit relatively large ventilation rates (such as 25 L/s per person) at modest or no cost increment. Overall, even in a thermally demanding tropical climate, the energy cost associated with increasing ventilation rate up to 25 L/s per person is less than 1% of the wages of an office worker in an advanced economy like Singapore's. This result implies that the benefits of increasing outdoor air ventilation rate up to 25 L/s per person--which is suggested to provide for productivity increases, lower sick building syndrome symptom prevalence, and reduced sick leave--can be much larger than the incremental cost of ventilation.

  2. Magnus air turbine system

    DOEpatents

    Hanson, Thomas F.

    1982-01-01

    A Magnus effect windmill for generating electrical power is disclosed. A large nacelle-hub mounted pivotally (in Azimuth) atop a support tower carries, in the example disclosed, three elongated barrels arranged in a vertical plane and extending symmetrically radially outwardly from the nacelle. The system provides spin energy to the barrels by internal mechanical coupling in the proper sense to cause, in reaction to an incident wind, a rotational torque of a predetermined sense on the hub. The rotating hub carries a set of power take-off rollers which ride on a stationary circular track in the nacelle. Shafts carry the power, given to the rollers by the wind driven hub, to a central collector or accumulator gear assembly whose output is divided to drive the spin mechanism for the Magnus barrels and the main electric generator. A planetary gear assembly is interposed between the collector gears and the spin mechanism functioning as a differential which is also connected to an auxiliary electric motor whereby power to the spin mechanism may selectively be provided by the motor. Generally, the motor provides initial spin to the barrels for start-up after which the motor is braked and the spin mechanism is driven as though by a fixed ratio coupling from the rotor hub. During high wind or other unusual conditions, the auxiliary motor may be unbraked and excess spin power may be used to operate the motor as a generator of additional electrical output. Interposed between the collector gears of the rotating hub and the main electric generator is a novel variable speed drive-fly wheel system which is driven by the variable speed of the wind driven rotor and which, in turn, drives the main electric generator at constant angular speed. Reference is made to the complete specification for disclosure of other novel aspects of the system such as, for example, the aerodynamic and structural aspects of the novel Magnus barrels as well as novel gearing and other power coupling

  3. Advanced Hybrid Spacesuit Concept Featuring Integrated Open Loop and Closed Loop Ventilation Systems

    NASA Technical Reports Server (NTRS)

    Daniel, Brian A.; Fitzpatrick, Garret R.; Gohmert, Dustin M.; Ybarra, Rick M.; Dub, Mark O.

    2013-01-01

    A document discusses the design and prototype of an advanced spacesuit concept that integrates the capability to function seamlessly with multiple ventilation system approaches. Traditionally, spacesuits are designed to operate both dependently and independently of a host vehicle environment control and life support system (ECLSS). Spacesuits that operate independent of vehicle-provided ECLSS services must do so with equipment selfcontained within or on the spacesuit. Suits that are dependent on vehicle-provided consumables must remain physically connected to and integrated with the vehicle to operate properly. This innovation is the design and prototype of a hybrid spacesuit approach that configures the spacesuit to seamlessly interface and integrate with either type of vehicular systems, while still maintaining the ability to function completely independent of the vehicle. An existing Advanced Crew Escape Suit (ACES) was utilized as the platform from which to develop the innovation. The ACES was retrofitted with selected components and one-off items to achieve the objective. The ventilation system concept was developed and prototyped/retrofitted to an existing ACES. Components were selected to provide suit connectors, hoses/umbilicals, internal breathing system ducting/ conduits, etc. The concept utilizes a lowpressure- drop, high-flow ventilation system that serves as a conduit from the vehicle supply into the suit, up through a neck seal, into the breathing helmet cavity, back down through the neck seal, out of the suit, and returned to the vehicle. The concept also utilizes a modified demand-based breathing system configured to function seamlessly with the low-pressure-drop closed-loop ventilation system.

  4. Non lineal respiratory systems mechanics simulation of acute respiratory distress syndrome during mechanical ventilation.

    PubMed

    Madorno, Matias; Rodriguez, Pablo O

    2010-01-01

    Model and simulation of biological systems help to better understand these systems. In ICUs patients often reach a complex situation where supportive maneuvers require special expertise. Among them, mechanical ventilation in patients suffering from acuter respiratory distress syndrome (ARDS) is specially challenging. This work presents a model which can be simulated and use to help in training of physicians and respiratory therapists to analyze the respiratory mechanics in this kind of patients. We validated the model in 2 ARDS patients.

  5. Definition and means of maintaining the ventilation system confinement portion of the PFP safety envelope

    SciTech Connect

    Dick, J.D.; Grover, G.A.; O`Brien, P.M., Fluor Daniel Hanford

    1997-03-05

    The Plutonium Finishing Plant Heating Ventilation and Cooling system provides for the confinement of radioactive releases to the environment and provides for the confinement of radioactive contamination within designated zones inside the facility. This document identifies the components and procedures necessary to ensure the HVAC system provides these functions. Appendices E through J provide a snapshot of non-safety class HVAC equipment and need not be updated when the remainder of the document and Appendices A through D are updated.

  6. Air-traffic surveillance systems

    NASA Technical Reports Server (NTRS)

    Macdoran, P. F.

    1979-01-01

    Passive ground-based radio-interferometry systems (RILS) monitor local air traffic by determining aircraft position in planes defined by surveillance area. Similar RILS arrangements are used to determine aircraft positions in three dimensions when combined with azimuth and range information obtained by radar. Information helps determine three-dimensional aircraft position without expensive encoding altimeters.

  7. Efficacy of body ventilation system for reducing strain in warm and hot climates.

    PubMed

    Chinevere, Troy D; Cadarette, Bruce S; Goodman, Daniel A; Ely, Brett R; Cheuvront, Samuel N; Sawka, Michael N

    2008-06-01

    This study determined whether a torso-vest forced ambient air body ventilation system (BVS) reduced physiological strain during exercise-heat stress. Seven heat-acclimated volunteers attempted nine, 2-h treadmill walks at 200 W m(-2) in three environments, -40 degrees C, 20% rh (HD), 35 degrees C, 75% rh (HW), and 30 degrees C, 50% rh, (WW) wearing the Army Combat Uniform, interceptor body armor (IBA) and Kevlar helmet. Three trials in each environment were BVS turned on (BVS(On)), BVS turned off (BVS(Off)), and no BVS (IBA). In HD, BVS(On) significantly lowered core temperature (T (re)), heart rate (HR), mean skin temperature (T (sk)), mean torso skin temperature (T (torso)), thermal sensation (TS), heat storage (S), and physiological strain index (PSI), versus BVS(Off) and IBA (P < 0.05). For HW (n = 6), analyses were possible only through 60 min. Exercise tolerance time (min) during HW was significantly longer for BVS(On) (116 +/- 10 min) versus BVS(Off) (95 +/- 22 min) and IBA (96 +/- 18 min) (P < 0.05). During HW, BVS(On) lowered HR at 60 min versus IBA, T (sk) from 30 to 60 min versus BVS(Off) and IBA, and PSI from 45 to 60 min versus BVS(Off) and at 60 min versus IBA (P < 0.05). BVS(On) changes in T (re) and HR were lower in HD and HW. During WW, BVS(On) significantly lowered HR, T (sk), and T (torso) versus BVS(Off) and IBA (P < 0.05) during late exercise. Sweating rates were significantly lower for BVS(On) versus BVS(Off) and IBA in both HD and WW (P < 0.05), but not HW. These results indicate that BVS(On) reduces physiological strain in all three environments by a similar amount; however, in hot-dry conditions the BVS(Off) increases physiological strain.

  8. A study on the ventilation method for a factory exposed to high temperature

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Lee, E.; Jeong, H.; Chung, H.

    2015-09-01

    On this work, the importance of industrial ventilation was investigated and examined the theoretical point and problems about general ventilation of factory exposed on high temperature during summer. As a case study, the ventilation planning of the PCB etching process for an electronic company was carried out and each of those characteristics were compared by installing actual ventilation systems and measuring the changing state of the working environment in accordance with ventilation method during summer. The purpose of the study is to present an efficient ventilation method for a factory with a closed structure under high temperature environment. In summary, for a factory with a sealed structure such as the target PCB manufacturing factory in this study, the forced supply and exhaust method was the most appropriate ventilation method for maintaining a low indoor air temperature and for keeping the contaminated air of the factory below the hazardous level.

  9. A microprocessor-controlled tracheal insufflation-assisted total liquid ventilation system.

    PubMed

    Parker, James Courtney; Sakla, Adel; Donovan, Francis M; Beam, David; Chekuri, Annu; Al-Khatib, Mohammad; Hamm, Charles R; Eyal, Fabien G

    2009-09-01

    A prototype time cycled, constant volume, closed circuit perfluorocarbon (PFC) total liquid ventilator system is described. The system utilizes microcontroller-driven display and master control boards, gear motor pumps, and three-way solenoid valves to direct flow. A constant tidal volume and functional residual capacity (FRC) are maintained with feedback control using end-expiratory and end-inspiratory stop-flow pressures. The system can also provide a unique continuous perfusion (bias flow, tracheal insufflation) through one lumen of a double-lumen endotracheal catheter to increase washout of dead space liquid. FRC and arterial blood gases were maintained during ventilation with Rimar 101 PFC over 2-3 h in normal piglets and piglets with simulated pulmonary edema induced by instillation of albumin solution. Addition of tracheal insufflation flow significantly improved the blood gases and enhanced clearance of instilled albumin solution during simulated edema.

  10. Optical air data systems and methods

    NASA Technical Reports Server (NTRS)

    Caldwell, Loren M. (Inventor); O'Brien, Martin J. (Inventor); Weimer, Carl S. (Inventor); Nelson, Loren D. (Inventor)

    2005-01-01

    Systems and methods for sensing air outside a moving aircraft are presented. In one embodiment, a system includes a laser for generating laser energy. The system also includes one or more transceivers for projecting the laser energy as laser radiation to the air. Subsequently, each transceiver receives laser energy as it is backscattered from the air. A computer processes signals from the transceivers to distinguish molecular scattered laser radiation from aerosol scattered laser radiation and determines one or more air parameters based on the scattered laser radiation. Such air parameters may include air speed, air pressure, air temperature and aircraft orientation angle, such as yaw, angle of attack and sideslip.

  11. Optical air data systems and methods

    NASA Technical Reports Server (NTRS)

    Caldwell, Loren M. (Inventor); Tang, Shoou-yu (Inventor); O'Brien, Martin (Inventor)

    2010-01-01

    Systems and methods for sensing air outside a moving aircraft are presented. In one embodiment, a system includes a laser for generating laser energy. The system also includes one or more transceivers for projecting the laser energy as laser radiation to the air. Subsequently, each transceiver receives laser energy as it is backscattered from the air. A computer processes signals from the transceivers to distinguish molecular scattered laser radiation from aerosol scattered laser radiation and determines one or more air parameters based on the scattered laser radiation. Such air parameters may include air speed, air pressure, air temperature and aircraft orientation angle, such as yaw, angle of attack and sideslip.

  12. On the thermal interaction of building structure and heating and ventilation system

    NASA Astrophysics Data System (ADS)

    Hensen, Joannes Laurentius Maria

    Developments in the field of building performance evaluation tools for thermal interaction of building structure and heating and ventilating systems are described. The technique employed is computer simulation of the integrated dynamic system comprising the occupants, the building and its heating and ventilating system. Assessment criteria from a literature review in thermal comfort to examine acceptable fluctuations in indoor climate are defined. Building and plant energy simulation within the context of Computer Aided Building Design (CABD) is described. An exisiting energy simulation environment ESP(R) (Environmental Systems Performance (Research version)) is chosen. A fluid flow network simulation module is described. Extensions to ESP(R) to predict the dynamic behavior of the heating and ventilation system are described. The coupling of fluid flow, plant side energy and mass, and building side energy simulation into one integrated program is described. A multistage verification and validation methodology is demonstrated by examples addressing each successive step. Imaginary and real world cases are described to demonstrate application of the study in a modeling orientated and a building engineering context.

  13. Brain Cooling With Ventilation of Cold Air Over Respiratory Tract in Newborn Piglets: An Experimental and Numerical Study

    PubMed Central

    Bakhsheshi, Mohammad Fazel; Moradi, Hadi Vafadar; Stewart, Errol E.; Keenliside, Lynn; Lee, Ting-Yim

    2015-01-01

    We investigate thermal effects of pulmonary cooling which was induced by cold air through an endotracheal tube via a ventilator on newborn piglets. A mathematical model was initially employed to compare the thermal impact of two different gas mixtures, O2-medical air (1:2) and O2-Xe (1:2), across the respiratory tract and within the brain. Following mathematical simulations, we examined the theoretical predictions with O2-medical air condition on nine anesthetized piglets which were randomized to two treatment groups: 1) control group (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$n = 4$ \\end{document}) and 2) pulmonary cooling group (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$n = 5$ \\end{document}). Numerical and experimental results using O2-medical air mixture show that brain temperature fell from 38.5 °C and 38.3 °C ± 0.3 °C to 35.7 °C ± 0.9 °C and 36.5 °C ± 0.6 °C during 3 h cooling which corresponded to a mean cooling rate of 0.9 °C/h ± 0.2 °C/h and 0.6 °C/h ± 0.1 °C/h, respectively. According to the numerical results, decreasing the metabolic rate and increasing air velocity are helpful to maximize the cooling effect. We demonstrated that pulmonary cooling by cooling of inhalation gases immediately before they enter the trachea can slowly reduce brain and core body temperature of newborn piglets. Numerical simulations show no significant differences between two different inhaled conditions, i.e., O2-medical air (1:2) and O2-Xe (1:2) with respect to cooling rate. PMID:27170888

  14. Measure Guideline: Ventilation Guidance for Residential High-Performance New Construction - Multifamily

    SciTech Connect

    Lstiburek, Joseph

    2017-01-01

    The measure guideline provides ventilation guidance for residential high performance multifamily construction that incorporates the requirements of the ASHRAE 62.2 ventilation and indoor air quality standard. The measure guideline focus is on the decision criteria for weighing cost and performance of various ventilation systems. The measure guideline is intended for contractors, builders, developers, designers and building code officials. The guide may also be helpful to building owners wishing to learn more about ventilation strategies available for their buildings. The measure guideline includes specific design and installation instructions for the most cost effective and performance effective solutions for ventilation in multifamily units that satisfies the requirements of ASHRAE 62.2-2016.

  15. Final Environmental Assessment Airfield Storm Drainage System Repair Joint Base Andrews-Naval Air Facility Washington, MD

    DTIC Science & Technology

    2015-06-01

    heating -ventilating- cooling systems , lawn maintenance, and general maintenance of streets and sidewalks. Existing noise levels (Leq and DNL) were...effort to rehabilitate JBA facilities including runway demolition and reconstruction. Please consider using solar geothermal systems to utilize...Final Environmental Assessment Airfield Storm Drainage System Repair Joint Base Andrews–Naval Air Facility Washington, Maryland Prepared for

  16. EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS (TBACT) DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEM SUPPORTING WASTE TRANSFER OPERATIONS

    SciTech Connect

    KELLY SE; HAASS CC; KOVACH JL; TURNER DA

    2010-06-03

    This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste throught the DST storage system to the Waste Treatment and Immobilization Plant (WTP).

  17. EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS -TBACT- DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEMS SUPPORTING WASTE TRANSFER OPERATIONS

    SciTech Connect

    HAAS CC; KOVACH JL; KELLY SE; TURNER DA

    2010-06-24

    This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste through the DST storage system to the Waste Treatment and Immobilizaiton Plant (WTP).

  18. Experimental and theoretical study of the oxidation of ventilation air methane over Fe2O3 and CuO.

    PubMed

    Jin, Yonggang; Sun, Chenghua; Su, Shi

    2015-07-07

    Coal mine ventilation air methane (VAM) is an important contributor to methane emissions from the energy sector. Although various technologies are under development, treatment of the VAM with an efficient and cost-effective approach has been an ongoing challenge due to massive flow rates of the ventilation air and low and variable methane concentrations. Recently a new concept based on the principle of chemical looping combustion (CLC) has been proposed for VAM abatement (Appl. Energy, 2014, 113, 1916), in which oxidation of low-concentration CH4 balanced by N2 with Fe2O3 or CuO as the oxygen carrier was studied. Here, we thoroughly examined the feasibility of CLC of VAM based on experimental study and theoretical calculations. Reduction of Fe2O3 and CuO and evolution of gas products during CH4 oxidation were investigated using TGA-MS under two reaction atmospheres: 1 vol% CH4 balanced by N2 and the simulated VAM containing 1 vol% CH4, 20 vol% O2, 0.4 vol% CO2 and balance N2. It was found that the CLC of VAM is fundamentally infeasible because the reduced phase of Fe2O3 and CuO cannot be formed for chemical looping when reacting with the simulated VAM containing abundant oxygen. Theoretical calculations revealed that Fe2O3 and CuO remain stable without the transition to the reduced phase as the generated oxygen vacancy on the surface of metal oxides during CH4 oxidation can recover quickly with O2 adsorption and dissociation. Calculations confirmed that both Fe2O3 and CuO play a role of surface catalyst in VAM oxidation. More importantly, it was found that the low-coordinated metal atoms and oxygen vacancies can stabilize CHx radicals to promote the dissociation of CH4, which is generally the rate-determining step for CH4 oxidation. Such findings are useful for new development and understanding of high-performance and low-cost metal oxide catalysts for CH4 oxidation.

  19. Ventilation during air breathing and in response to hypercapnia in 5 and 16 month-old mdx and C57 mice

    PubMed Central

    Gayraud, Jérome; Matécki, Stefan; Hnia, Karim; Mornet, Dominique; Préfaut, Christian; Mercier, Jacques; Michel, Alain; Ramonatxo, Michèle

    2007-01-01

    Previous studies have shown a blunted ventilatory response to hypercapnia in mdx mice older than 7 months. We test the hypothesis that in the mdx mice ventilatory response changes with age, concomitantly with the increased functional impairment of the respiratory muscles. We thus studied the ventilatory response to CO2 in 5 and 16 month-old mdx and C57BL10 mice (n = 8 for each group). Respiratory rate (RR), tidal volume (VT), and minute ventilation (VE) were measured, using whole-body plethysmography, during air breathing and in response to hypercapnia (3, 5 and 8% CO2). The ventilatory protocol was completed by histological analysis of the diaphragm and intercostals muscles. During air breathing, the 16 month-old mdx mice showed higher RR and, during hypercapnia (at 8% CO2 breathing), significantly lower RR (226 ± 26 vs. 270 ± 21 breaths/min) and VE (1.81 ± 0.35 vs. 3.96 ± 0.59 ml min−1 g−1)(P < 0.001) in comparison to C57BL10 controls. On the other hand, 5 month-old C57BL10 and mdx mice did not present any difference in their ventilatory response to air breathing and to hypercapnia. In conclusion, this study shows similar ventilation during air breathing and in response to hypercapnia in the 5 month-old mdx and control mice, in spite of significant pathological structural changes in the respiratory muscles of the mdx mice. However in the 16 month-old mdx mice we observed altered ventilation under air and blunted ventilation response to hypercapnia compared to age-matched control mice. Ventilatory response to hypercapnia thus changes with age in mdx mice, in line with the increased histological damage of their respiratory muscles. PMID:17431804

  20. Existing Whole-House Solutions Case Study: Multifamily Individual Heating and Ventilation Systems, Lawrence, Massachusetts

    SciTech Connect

    2013-11-01

    The conversion of an older Massachusetts building into condominiums illustrates a safe, durable, and cost-effective solution for heating and ventilation systems that can potentially benefit millions of multifamily buildings. In this project, Merrimack Valley Habitat for Humanity (MVHfH) partnered with U.S. Department of Energy Building America team Building Science Corporation (BSC) to provide high performance affordable housing for 10 families in the retrofit of an existing mass masonry building (a former convent).

  1. Double shell tank primary ventilation exhaust flow monitor system design description

    SciTech Connect

    Willingham, W.E., Fluor Daniel Hanford

    1997-03-11

    This document describes the flow monitoring systems that will be installed on the ventilation exhaust ducts of the flammable gas watch list double shell tanks (241-AN-103, 241-AN-104, 241-AN-105, 241-AN-107, 241-AW-101 and 241-SY-103), the saltwell receiver tanks (241-AN-101 and 241-SY-102) and the cross-site receiver tank (241-AP-104).

  2. Why We Ventilate

    SciTech Connect

    Logue, Jennifer M.; Sherman, Max H.; Price, Phil N.; Singer, Brett C.

    2011-09-01

    It is widely accepted that ventilation is critical for providing good indoor air quality (IAQ) in homes. However, the definition of"good" IAQ, and the most effective, energy efficient methods for delivering it are still matters of research and debate. This paper presents the results of work done at the Lawrence Berkeley National Lab to identify the air pollutants that drive the need for ventilation as part of a larger effort to develop a health-based ventilation standard. First, we present results of a hazard analysis that identified the pollutants that most commonly reach concentrations in homes that exceed health-based standards or guidelines for chronic or acute exposures. Second, we present results of an impact assessment that identified the air pollutants that cause the most harm to the U.S. population from chronic inhalation in residences. Lastly, we describe the implications of our findings for developing effective ventilation standards.

  3. Residential Ventilation: A Review of Established Systems and a Laboratory Investigation of the Fine Wire Heat Recovery Ventilator

    NASA Astrophysics Data System (ADS)

    von Hippel, Matthew Hans Benjamin

    A novel vehicle concept is introduced and its feasibility as an autonomous, self-propelled weather buoy for use in violent storm systems is analyzed. The vehicle concept is a spar sailboat -- consisting of only a deep keel and a sailing rig; no hull -- a design which is intended to improve longevity in rough seas as well as provide ideal placement opportunities for meteorological sensors. To evaluate the hypothetical locomotive and meteorological observation capabilities of the concept sailing spar in hurricane-like conditions, several relevant oceanographic phenomena are analyzed with the performance of the concept vehicle in mind. Enthalpy transfer from the ocean to the air is noted as the primary driving force of tropical storms and therefore becomes the measuring objective of the sailing spar. A discrete, iterative process for optimizing driving force while achieving equilibrium between the four airfoil surfaces is used to steer the sailing spar towards any objective despite variable and opposing simulated winds. Based on the limitations of sailing theory, logic is developed to autonomously navigate the sailing spar between human-selected waypoints on a digitized geographic map. Due the perceived inability to measure air-sea enthalpy exchange because the nature of tropical storms and due to its small scale, the sailing spar is deemed infeasible as a hurricane-capable meteorological observation platform.

  4. Air Sampling System Evaluation Template

    SciTech Connect

    Blunt, Brent

    2000-05-09

    The ASSET1.0 software provides a template with which a user can evaluate an Air Sampling System against the latest version of ANSI N13.1 "Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities". The software uses the ANSI N13.1 PIC levels to establish basic design criteria for the existing or proposed sampling system. The software looks at such criteria as PIC level, type of radionuclide emissions, physical state of the radionuclide, nozzle entrance effects, particulate transmission effects, system and component accuracy and precision evaluations, and basic system operations to provide a detailed look at the subsystems of a monitoring and sampling system/program. A GAP evaluation can then be completed which leads to identification of design and operational flaws in the proposed systems. Corrective measures can then be limited to the GAPs.

  5. Risk Factors in Heating, Ventilating, and Air-Conditioning Systemsfor Occupant Symptoms in U.S. Office Buildings: the EPA BASE Study

    SciTech Connect

    Mendell, M.J.; Lei-Gomez, Q.; Mirer, A.; Seppanen, O.; Brunner, G.

    2006-10-01

    Nonspecific building-related symptoms among occupants of modern office buildings worldwide are common and may be associated with important reductions in work performance, but their etiology remains uncertain. Characteristics of heating, ventilating, and air-conditioning (HVAC) systems in office buildings that increase risk of indoor contaminants or reduce effectiveness of ventilation may cause adverse exposures and subsequent increase in these symptoms among occupants. We analyzed data collected by the U.S. EPA from a representative sample of 100 large U.S. office buildings--the Building Assessment and Survey Evaluation (BASE) study--using multivariate logistic regression models with generalized estimating equations adjusted for potential personal and building confounders. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between seven building-related symptom outcomes and selected HVAC system characteristics. Among factors of HVAC design or configuration: Outdoor air intakes less than 60 m above the ground were associated with approximately doubled odds of most symptoms assessed. Sealed (non-operable) windows were associated with increases in skin and eye symptoms (ORs= 1.9, 1.3, respectively). Outdoor air intake without an intake fan was associated with an increase in eye symptoms (OR=1.7). Local cooling coils were associated with increased headache (OR=1.5). Among factors of HVAC condition, maintenance, or operation: the presence of humidification systems in good condition was associated with an increase in headache (OR=1.4), whereas the presence of humidification systems in poor condition was associated with increases in fatigue/difficulty concentrating, as well as upper respiratory symptoms (ORs=1.8, 1.5). No regularly scheduled inspections for HVAC components was associated with increased eye symptoms, cough and upper respiratory symptoms (ORs=2.2, 1.6, 1.5). Less frequent cleaning of cooling coils or drip pans was associated

  6. 78 FR 51749 - Proposed Information Collection; Ventilation Plan and Main Fan Maintenance Record (Pertains to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ... operating ventilation system is essential for maintaining a safe and healthful working environment. A well planned mine ventilation system is necessary to assure a fresh air supply to miners at all working places... protecting the safety and health of miners. Underground mines usually present harsh and hostile...

  7. Does Mixing Make Residential Ventilation More Effective?

    SciTech Connect

    Sherman, Max; Walker, Iain

    2010-08-16

    Ventilation dilutes or removes indoor contaminants to reduce occupant exposure. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. The total ventilation rate is the most important factor in determining the exposure of occupants to given sources, but the zone- specific distribution of exhaust and supply air, and the mixing of ventilation air can have significant roles. Different types of ventilation systems will provide different amounts of mixing depending on several factors such as air leakage through the building envelope, air distribution systems and the location of sources and occupants. This paper reports recent results of investigations to determine the impact that air mixing has on exposures of residential occupants to prototypical contaminants of concern. Evaluations of existing field measurements and simulations reported in the literature are combined with new analyses to provide an integrated overview of the topic. The results show that for extreme cases additional mixing can be a significant factor but for typical homes looking at average exposures mixing is not helpful and can even make exposures worse.

  8. [Collecting end-expiratory air for capnography in high-frequency jet ventilation].

    PubMed

    Rockemann, M G; Doehn, M

    1985-04-01

    By means of an ejector attachment to the endotracheal tube a negative intratracheal pressure of approx. -1 mmHg is created during an interruption of HFJV. Within 4 to 10 sec. this suction supplies alveolar air to the distal end of the endotracheal tube where capnographic analysis is possible in the mainstream or bystream. The end-tidal pCO2 differs by 0.1 mmHg (mean) from the arterial carbon dioxide partial pressure with a highly positive correlation (R = 0.98).

  9. 46 CFR 194.20-5 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND... system shall have a capacity sufficient to effect a complete change of air in not more than 4 minutes based upon the volume of the compartment. (1) Power ventilation units shall have nonsparking...

  10. 46 CFR 194.20-5 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND... system shall have a capacity sufficient to effect a complete change of air in not more than 4 minutes based upon the volume of the compartment. (1) Power ventilation units shall have nonsparking...

  11. 46 CFR 194.20-5 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND... system shall have a capacity sufficient to effect a complete change of air in not more than 4 minutes based upon the volume of the compartment. (1) Power ventilation units shall have nonsparking...

  12. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND... emergencies. The system shall have a capacity sufficient to effect a complete change of air in not more than 4 minutes based upon the volume of the compartment. (1) Power ventilation units shall have...

  13. [A design of simple ventilator control system based on LabVIEW].

    PubMed

    Pei, Baoqing; Xu, Shengwei; Li, Hui; Li, Deyu; Pei, Yidong; He, Haixing

    2011-01-01

    This paper designed a ventilator control system to control proportional valves and motors. It used LabVIEW to control the object mentioned above and design ,validate, evaluate arithmetic, and establish hardware in loop platform. There are two system' s hierarchies. The high layer was used to run non-real time program and the low layer was used to run real time program. The two layers communicated through TCP/IP net. The program can be divided into several modules, which can be expanded and maintained easily. And the harvest in the prototype designing can be seamlessly used to embedded products. From all above, this system was useful in employing OEM products.

  14. Thermal storage HVAC system retrofit provides economical air conditioning

    SciTech Connect

    Smith, S.F. )

    1993-03-01

    This article describes an EMS-controlled HVAC system that meets the ventilation and cooling needs of an 18,000-seat indoor ice hockey arena. The Buffalo Memorial Auditorium (affectionately referred to as the Aud) was built in 1937 under the Works Project Administration of the federal government. Its original configuration included a 12,000-seat arena with an ice skating rink. By the late 1980s, the city was unsuccessfully attempting to attract events and tenants to the auditorium, which lacked air conditioning and other modern amenities. Thus, it was decided to renovate the facility to make it marketable. The first phase of the renovation included installing an air-conditioning system in the arena and repairing the existing building systems that were inoperable because of deferred maintenance. After considering the existing conditions (such as size of the space, intermittent usage, construction restrictions, operating budgets and the limited operations staff), the engineering team designed an innovative HVAC system. The system's features include: a carbon dioxide monitoring device that controls the intake of outside air; an ice storage system that provides chilled water and shifts electrical demand to off-peak hours; and a design that uses the building mass as a heat sink. A new energy management system (EMS) determines building cooling needs based on the type of event, ambient conditions and projected audience size. Then, it selects the most economical method to obtain the desired arena temperature.

  15. Online Design Aid for Evaluating Manure Pit Ventilation Systems to Reduce Entry Risk.

    PubMed

    Manbeck, Harvey B; Hofstetter, Daniel W; Murphy, Dennis J; Puri, Virendra M

    2016-01-01

    On-farm manure storage pits contain both toxic and asphyxiating gases such as hydrogen sulfide, carbon dioxide, methane, and ammonia. Farmers and service personnel occasionally need to enter these pits to conduct repair and maintenance tasks. One intervention to reduce the toxic and asphyxiating gas exposure risk to farm workers when entering manure pits is manure pit ventilation. This article describes an online computational fluid dynamics-based design aid for evaluating the effectiveness of manure pit ventilation systems to reduce the concentrations of toxic and asphyxiating gases in the manure pits. This design aid, developed by a team of agricultural engineering and agricultural safety specialists at Pennsylvania State University, represents the culmination of more than a decade of research and technology development effort. The article includes a summary of the research efforts leading to the online design aid development and describes protocols for using the online design aid, including procedures for data input and for accessing design aid results. Design aid results include gas concentration decay and oxygen replenishment curves inside the manure pit and inside the barns above the manure pits, as well as animated motion pictures of individual gas concentration decay and oxygen replenishment in selected horizontal and vertical cut plots in the manure pits and barns. These results allow the user to assess (1) how long one needs to ventilate the pits to remove toxic and asphyxiating gases from the pit and barn, (2) from which portions of the barn and pit these gases are most and least readily evacuated, and (3) whether or not animals and personnel need to be removed from portions of the barn above the manure pit being ventilated.

  16. Online Design Aid for Evaluating Manure Pit Ventilation Systems to Reduce Entry Risk

    PubMed Central

    Manbeck, Harvey B.; Hofstetter, Daniel W.; Murphy, Dennis J.; Puri, Virendra M.

    2016-01-01

    On-farm manure storage pits contain both toxic and asphyxiating gases such as hydrogen sulfide, carbon dioxide, methane, and ammonia. Farmers and service personnel occasionally need to enter these pits to conduct repair and maintenance tasks. One intervention to reduce the toxic and asphyxiating gas exposure risk to farm workers when entering manure pits is manure pit ventilation. This article describes an online computational fluid dynamics-based design aid for evaluating the effectiveness of manure pit ventilation systems to reduce the concentrations of toxic and asphyxiating gases in the manure pits. This design aid, developed by a team of agricultural engineering and agricultural safety specialists at Pennsylvania State University, represents the culmination of more than a decade of research and technology development effort. The article includes a summary of the research efforts leading to the online design aid development and describes protocols for using the online design aid, including procedures for data input and for accessing design aid results. Design aid results include gas concentration decay and oxygen replenishment curves inside the manure pit and inside the barns above the manure pits, as well as animated motion pictures of individual gas concentration decay and oxygen replenishment in selected horizontal and vertical cut plots in the manure pits and barns. These results allow the user to assess (1) how long one needs to ventilate the pits to remove toxic and asphyxiating gases from the pit and barn, (2) from which portions of the barn and pit these gases are most and least readily evacuated, and (3) whether or not animals and personnel need to be removed from portions of the barn above the manure pit being ventilated. PMID:27303661

  17. Numerical simulations of the flowfields of industrial ventilation systems and solar rocket plume

    SciTech Connect

    Yu, Shengtao.

    1989-01-01

    The motivation for this research is to incorporate modern numerical methods in modeling the flowfields of two systems: (1) industrial ventilation systems and (2) solar rocket plume. For both systems, calculations of the velocity, temperature, turbulence properties, and species concentration of flowfields were performed. Brief discussions of the two topics follow: (1) Industrial ventilation systems. An open vessel equipped with a push-pull ventilation system to control toxic vapor and a flanged suction inlet to control grinding particles and welding fumes has been analyzed. The computational method involves solving the two-dimensional turbulent flow equations for the conservation of mass, momentum, energy, turbulence properties, and chemical species in finite form. The method provides information needed by engineers to assess the effectiveness of their designs. In order to verify the accuracy of the theoretical analysis, a two-dimensional push-pull system prototype was set up and color schlieren photography and hot wire anemometry were performed. Favorable agreement was found between the experimental data and calculated results. (2) Solar rocket plume. The interaction of the solar rocket plume and the solar concentrator is studied by flow-field analysis. Such interaction can adversely affect the collector performance through fouling, excessive heat, or pressure loading. The geometrical shape of the concentrator is such that only the flow from the nozzle boundary layer can reach it, but the thrust levels of interest lead to very thick boundary layers. A time-marching Parabolized Navier-Stokes (PNS) scheme is developed to calculate the flowfields inside nozzles. The Method of Characteristics (MOC) is used to simulate the flow of rocket plume. Results show that both pressure and heat transfer effects are low, but that they increase as the chamber pressure or the thrust level size is reduced.

  18. 30 CFR 75.326 - Mean entry air velocity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Mean entry air velocity. 75.326 Section 75.326... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.326 Mean entry air velocity. In exhausting face ventilation systems, the mean entry air velocity shall be at least 60 feet per...

  19. Users Guide to Direct Digital Control of Heating, Ventilating, and Air Conditioning Equipment,

    DTIC Science & Technology

    1985-01-01

    feet downstream from the damper. For most HVAC applications, PI control is an adequate control technique. A more detailed description of PID control is...dectricityU nt Figure 13. Comparison of energy consumption of two HVAC Systems with PI Control . (Ref 2) 26 Conventional Built-up Control System, Control

  20. Strategy Guideline. Compact Air Distribution Systems

    SciTech Connect

    Burdick, Arlan

    2013-06-01

    This guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.