Effects of HVAC System and Building Characteristics on Exposure of Occupants to Short-Duration Point Source Aerosol Releases
Publication: Journal of Architectural Engineering
Volume 13, Issue 2
Abstract
This paper presents results from the simulation of localized, short-duration bioaerosol releases in a hypothetical building similar to a dormitory or barracks using public domain multizone air flow and contaminant dispersion modeling software. The primary purpose of the modeling was to generate example exposure data to be used in the development of a comprehensive microbial risk assessment methodology. However, these results are also of intrinsic interest for what they reveal about the contribution of various building characteristics to risk from airborne contaminants. A variety of parameters were varied, including building construction, heating, ventilating, and air-conditioning (HVAC) system design, and release characteristics, among others. Results of these simulations demonstrate the variability of exposure possible under different scenarios and, more particularly, the impact that HVAC design decisions can have on risk. Although a single building and restricted set of scenarios was investigated, several general conclusions could be drawn regarding factors, such as HVAC zoning and filter maintenance, that intrinsically contribute to vulnerability reduction.
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Acknowledgments
The support of this work by U.S. Army Center for Health Promotion and Preventive Medicine (USACHPPM) Contract Nos. UNSPECIFIEDDABJ05-03-P-1210 and UNSPECIFIEDW91ZLK-05-P-0838 is gratefully acknowledged.
References
Achakji, G. Y., and Tamura, G. T. (1988). “Pressure drop characteristics of typical stairshafts in high-rise buildings.” ASHRAE Trans., 94(1), 1223–1237.
American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). (1999). “Method of testing general ventilation air-cleaning devices for removal efficiency by particle size.” Standard 52.2, Atlanta.
American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). (2003). Risk management guidance for health, safety, and environmental security under extraordinary incidents, Atlanta.
American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). (2004). “Ventilation for acceptable indoor air quality.” Standard 62-2004, Atlanta.
American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). (2005). 2005 ASHRAE handbook: Fundamentals, Atlanta.
Bahnfleth, W. P. (2004). “Reducing building vulnerability: Recent guidance documents.” HPAC engineering, ⟨http://www.engr.psu.edu/ae/iec/publications/articles/reducing_vulnerability.pdf⟩ (February 21, 2007).
Bahnfleth, W. P., and Volcheck, J. R. (2003) “Security as a design parameter for heating, ventilation and air-conditioning systems.” International Congress of Refrigeration, Washington, D.C.
Crump, J. G., and Seinfeld, J. H. (1981). “Turbulent deposition and gravitational sedimentation of an aerosol in a vessel of arbitrary shape.” J. Aerosol Sci., 12(5), 405–415.
Dols, W. S., and Walton, G. N. (2002). NISTIR 6921: CONTAM 2.0 user’s manual, National Institute of Standards and Technology, Washington, D.C.
Federal Emergency Management Agency (FEMA). (2003). “Reference manual to mitigate potential terrorist attacks against buildings.” FEMA 426, Washington, D.C.
Gomes, C., Freihaut, J., and Bahnfleth, W. (2005). “Resuspension of allergen-containing particles under mechanical and aerodynamic disturbances from human walking—introduction to an experimental controlled methodology.” Proc., 10th Int. Conf. on Indoor Air Quality and Climate, Beijing.
Hanley, J. T., Ensor, D. S., Smith, D. D., and Sparks, L. E. (1994). “Fractional aerosol filtration efficiency of in-duct ventilation air cleaners.” Indoor Air, 4(3), 169–178.
Mumma, S. A. (2001). “Overview of integrating dedicated outdoor air systems with parallel terminal systems.” ASHRAE Trans., 107(1), 681–187.
Musser, A., Schwabe, O., and Nabinger, S. (2001). “Validation and calibration of a multizone network airflow model with experimental data.” Proc., eSim Canada Conf., 228–235.
Narazoff, W. W., and Cass, G. R. (1989). “Mathematical modeling of indoor aerosol dynamics.” Environ. Sci. Technol., 23(2), 157–166.
Persily, A. K. (1999) “Myths about building envelopes.” ASHRAE J., 41(3), 39–45.
Persily, A. K., and Gorfain, J. (2004). “Analysis of ventilation data from the U.S. Environmental Protection Agency building assessment survey and evaluation (BASE) study.” NISTIR 7145, National Institute of Standards and Technology, Washington, D.C.
Persily, A. K., and Ivy, E. M. (2001). “Input data for multizone airflow and IAQ analysis.” NISTIR 6585, National Institute of Standards and Technology, Washington, D.C.
Price, P. N., et al. (2003). “Protecting buildings from a biological or chemical attack: Actions to take before or during a release.” LBNL/PUB-51959, Lawrence Berkeley National Laboratory, Berkeley, Calif.
Riley, W. J., McKone, T. E., Lai, A. C. K., and Nazaroff, W. W. (2002). “Indoor particulate matter of outdoor origin: Importance of size-dependent removal mechanisms.” Environ. Sci. Technol., 36(2), 200–207.
Sohn, M. D., Sextro, R. G., Gadgil, A. J., and Daisey, J. M., (2003). “Responding to sudden pollutant releases in office buildings. I. Framework and analysis tools.” Indoor Air, 13, 267–276.
Upham, R., Yuill, G., and Bahnfleth, W. (2001). “A validation study of multizone air flow and contaminant migration simulation programs as applied to tall buildings.” ASHRAE Trans., 107(2), 629–644.
U.S. Army Corps of Engineers (USACE). (2001). “Protecting buildings and their occupants from airborne hazards.” TI 853-01, Washington, D.C.
U.S. Dept. of Defense (DoD). (2002). “DoD minimum antiterrorism standards for buildings.” UFC 4-010-01, Washington, D.C.
U.S. Environmental Protection Agency (USEPA). (1997). “Exposure factors handbook, Volume 1—General factors.” EPA/600/P-95/002Fa, Washington, D.C.
Ward, M., and Siegel, J. A. (2005). “Filter bypass: Implications for filter efficiency.” ASHRAE Trans., 111(2), 1091–110.
Weis, C. P., Intrepido, A. J., Miller, A. K., Cowin, P. G., Durno, M. A., Gebhart, J. S., and Bull, R. (2002). “Secondary aerosolization of viable Bacillus anthracis spores in contaminated U.S. Senate office.” J. Am. Med. Assoc., 288(22), 2853–2858.
Xu, M., Nematollahi, M., Sextro, R. G., Gadgil, A. J., and Nazaroff, W. W. (1994). “Deposition of tobacco smoke particles in a low ventilation room.” Aerosol Sci. Technol., 20, 194–206.
Information & Authors
Information
Published In
Journal of Architectural Engineering
Volume 13 • Issue 2 • June 2007
Pages: 84 - 94
Copyright
© 2007 ASCE.
History
Received: Jan 27, 2006
Accepted: Aug 9, 2006
Published online: Jun 1, 2007
Published in print: Jun 2007
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