Abstract
Use of a HEPA (high efficiency particulate air) filter in a room is believed to assist in reducing the risk of transmission of infectious diseases through removing the particles or large droplets to which pathogens may be attached. Use of a portable HEPA filter(s) in hospital wards is hypothesized to increase the effective ventilation rate (for particles only). Use of a portable HEPA filter is also hypothesized to increase the effective airflow rate of the general ward to the standard of an isolation ward for emerging infection diseases. This may be a good solution for housing patients when the number of beds in an isolation ward is insufficient. An experiment was conducted in a full scale experimental ward with a dimension of 6.7 m × 6 m × 2.7 m and 6 beds to test these hypotheses for a portable HEPA filter. The removal efficiency for different size particles was measured at different locations. The influence of the portable HEPA air cleaner on the airflow pattern was also studied through smoke visualization and computational fluid dynamics (CFD) simulations. Results show that the HEPA filter can effectively decrease the particle concentration level. The effective air change rate achieved by the HEPA filter (for particle removal only) is from 2.7 to 5.6 ACH in the ward. The strong supply air jet from the portable HEPA filter interacted with the room airflow pattern and became dominate, introducing global airflow mixing in the room. Background noise levels were also measured and noise level in the room increased when the maximum airflow of the filter was used.
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References
AEA Technology (1994). Testing of HEPA and ventilation filters. Filtration & Separation, 31,781.
Antonicelli L, Bilo MB, Pucci S, Schou C, Bonifazi F (1991). Efficacy of an air-cleaning device equipped with a high-efficiency particulate air filter in house dust mite respiratory allergy. Allergy, 46: 594–600.
Brohus H (1997). Personal exposure to contaminant sources in ventilated rooms (p. 22). Department of Building Technology and Structural Engineering. Aalborg University, Aalborg.
Center for Disease Control and Prevention (CDC) (2003). Guidelines for Environmental Infection Control in Health-Care Facilities. U.S. Department of Health and Human Services Centers for Disease Control and Prevention (CDC), Atlanta, USA.
Cheng YS, Lu JC, Chen TR (1998). Efficiency of a portable indoor air cleaner in removing pollens and fungal spores. Aerosol Science and Technology, 29: 92–101.
Cheong CD, Neumeister-Kemp HG., Dingle PW, Hardy GS (2004). Intervention study of airborne fungal spora in homes with portable HEPA filtration units. Journal of Environmental Monitoring, 6: 866–873.
Emmerich SJ, Nabinger SJ (2001). Measurement and simulation of the IAQ impact of particle air cleaners in a single-zone building. HVAC&R Research, 7: 223–244.
Ferziger JH, Peric M (2002). Computational Methods for Fluid Dynamics, 3rd edn. Berlin: Springer.
Johnson AE, Brown RC (1998). Measurement of the performance of air cleaners against the particulate element of rosin-based solder flux fume. Annals of Occupational Hygiene, 42: 511–519.
Lam KS, Chan FS, Fung WY, Lui BSS, Lau LWL (2006). Achieving ‘excellent’ indoor air quality in commercial offices equipped with air-handling unit-respirable suspended particulate. Indoor Air, 16: 86–97.
Novoselac A, Siegel JA (2009). Impact of placement of portable air cleaning devices in multizone residential environments. Building and Environment, 44: 2348–2356.
Ward M, Siegel JA, Corsi RL (2005). The effectiveness of stand alone air cleaners for shelter-in-place. Indoor Air, 15: 127–134.
Zhang T, Wang S, Sun G, Xu L, Takaoka D (2010). Flow impact of an air conditioner to portable air cleaning. Building and Environment, 15, 2047–2056.
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Qian, H., Li, Y., Sun, H. et al. Particle removal efficiency of the portable HEPA air cleaner in a simulated hospital ward. Build. Simul. 3, 215–224 (2010). https://doi.org/10.1007/s12273-010-0005-4
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DOI: https://doi.org/10.1007/s12273-010-0005-4