Standard heating, ventilation, and air conditioning (HVAC) systems in healthcare facilities are designed to: (1) maintain air temperature and humidity at comfortable levels for HCWs and patients; (2) control odors; (3) remove contaminated air; (4) facilitate air-handling requirements to protect susceptible HCWs and patients from airborne healthcare-associated pathogens; and (5) minimize the risk for transmission of airborne pathogens from infected patients.¹ Failure or malfunction of any component of the HVAC systems (e.g., outside air intake; filters; humidity modification mechanisms; heating and cooling equipment; fans; ductwork; air exhaust or out-takes; and registers, diffusers, or grilles for the proper distribution of air) can contribute to unacceptable indoor air quality and the spread of healthcare-associated airborne pathogens. Recommendations to maintain acceptable indoor air quality in healthcare settings are summarized in Table 3.^1,2,6 

Areas in healthcare settings that require special ventilation include: (1) operating rooms (ORs), (2) protective environment (PE) rooms, and (3) airborne infection isolation (AII) rooms.¹ Community-based oral healthcare facilities are not expected to maintain areas that require special ventilation (e.g., ORs, PE rooms, and AII rooms).²