LV-17-C009 -- Proposed Outdoor Air Ventilation Rates for Health Care Facilities ✓ Most Recent

Health care facilities use an outdoor air ventilation rate of 2 air change per hour (ACH) for most spaces. This number can be traced back to thearchitectural literature of the 1870s. It has been carried forward in codes and standards for nearly 140 years (!), and currently is in ASHRAE Standard170. This paper proposes an alternative rationale for outdoor air ventilation in health care spaces, based on the contemporary methodologies of ASHRAEStandard 62.1, and benchmarked against other sources. A table of spaces and outdoor air ventilation rates is presented, with supporting rationale for therates. This paper deals only with outdoor air, and excludes consideration and comparisons of total ventilation rate or other ventilation variables.