Notes that dental facilities need special ventilation considerations because of the work typically performed in them. Bioaerosols and particulates are routinely generated potentially at concentrations of concern. Analgesia with nitrous oxide is another concern. Refers to the limited guidance in the U.S. on ventilation design for dental offices. States that a well-engineered ventilation design should provide acceptable indoor air quality for the dental professionals in the office as well as the patients. Deals with areas typically associated with dental units within institutional facilities such as medical centres and health clinics. Concludes that ventilation criteria recommended by federal agencies has given generally satisfactory results but considering the particulates/contaminants that are present it seems prudent to equip the ventilation system with filters rated at an ASHRAE dust spot of 60% or higher. In addition, the use of N₂O, the selection of sterilisation methods and the use of HVEs can significantly affect the IAQ and must be taken into account to achieve an effective HVAC system.