As engineers, our challenge is to achieve safe and healthy care spaces while minimizing environmental impact.

Many engineers seem open to reconsidering health-care ventilation standards. Most, though, are wary, convinced ACH rates exist to provide infection control when, in fact, much of “the table” is based more on history and consensus than evidence.

Because engineers seem to understand infection-control fundamentals, the restrictive and prescriptive nature of the table may be unwarranted. A one-size-fits-all approach may have been appropriate when the table was created a quarter-century ago, but, today, in light of energy concerns, growing knowledge of IAQ, and ASHRAE’s commitment to sustainability, it deserves reconsideration.


1) AIA. (1987). Guidelines for design and construction of hospital and health care facilities. Washington, DC: American Institute of Architects.

2) Doty, S.P. (2009). Simultaneous heating and cooling—The hvac blight. Energy Engineering, 106, 2, 42-74.

3) California Building Standards Commission. (1981). California building code. Title 24, Part 2, Section 2-5329.

4) EIA. (n.d.). Commercial buildings energy consumption survey (cbecs). Retrieved from

5) Atkinson, J., Chartier, Y., Pessoa-Silva, C.L., Jensen, P., Li, Y., & Seto, W. (Eds). (2009). Natural ventilation for infection control in health-care settings. Geneva: World Health Organization.

6) Memarzadeh, F. (2013). Literature review: Room ventilation and airborne disease transmission. Chicago: American Society for Healthcare Engineering.

7) Hermans, R.D., & Streifel, A.J. (1993). Ventilation designs. Proceedings of the Workshop on Engineering Controls for Preventing Airborne Infections in Workers in Healthcare and Related Facilities.

8) Memarzadeh, F., & Manning, A. (2000). Thermal comfort, uniformity, and ventilation effectiveness in patient rooms: Performance assessment using ventilation indices. ASHRAE Transactions, 106 (2).

9) Siegel, J.D., Rhinehart, E., Jackson, M., Chiarello, L., & HICPAC. (2007). 2007 guideline for isolation precautions: Preventing transmission of infectious agents in healthcare settings (p. 17). Retrieved from

10) CDC & HICPAC. (2004). Guidelines for environmental infection control in health-care facilities. Chicago: American Society for Healthcare Engineering/American Hospital Association.

11) CDC. (2005, December 30). Guidelines for preventing the transmission of mycobacterium tuberculosis in health-care settings, 2005 (p. 18). Morbidity and Mortality Weekly Report.


Travis R. English, PE, CEM, LEED AP, is engineering manager for health-care provider Kaiser Permanente’s National Facilities Planning group. He has more than 18 years of experience in the design and construction administration of mechanical and power-distribution systems for institutional, commercial, laboratory, and health-care facilities. His experience encompasses renewable-power systems, net-zero-building design, and building control systems.


Did you find this article useful? Send comments and suggestions to Executive Editor Scott Arnold at