The medical staff in patient rooms and especially in isolation rooms, are exposed for airborne contaminants. Wearing personal protective equipment, like masks, gloves, gowns etc. does not always guarantee complete protection against airborne infections for healthcare workers and visitors and hence complementary protection is needed. Typically, ventilation design guidelines suggest total volume mixing ventilation to be used in hospital isolation rooms[i]. However, this strategy might not always be the most effective option against airborne pathogens since medical staff can be exposed to high pathogen concentrations released by the patient especially when they are close to the patient giving care. Optimal supply air distribution design should dilute the high concentrations readily close to the source, direct the contaminants away from the healthcare staff breathing zone and still provide comfortable environment for the occupants.
[i] CDC 2005, DIN 1946-4, ASHRAE 170-2013