Transmission of Exhaled Air between Occupants in Rooms with Personalized and Underfloor Ventilation

Air exhaled by occupants may carry infectious agents and be one way of transmitting respiratory diseases in rooms. The exposure of occupants to exhaled air was examined at two different throw heights of underfloor ventilation combined with two types of personalized ventilation by means of full-scale experiments. The concentration of exhaled air from one occupant was measured in air inhaled by another occupant who used or did not use personalized ventilation. The results showed that the type of personalized ventilation, together with the throw height of underfloor ventilation, affects mixing in the occupied zone and thus has a substantial impact on the transmission of exhaled air.