Personal exposure in a displacement ventilated room is examined. The stratified flow and the considerable concentration gradients necessitate an improvement of the widely used fully mixing compartmental approach. The exposure of a seated and a standing person in proportion to the stratification height is examined by means of fullscale measurements. A breathing thermal manikin is used to simulate a person. It is found that the flow in the boundary layer around a person is able to a great extent to entrain and transport air from below the breathing zone.

Mechanical ventilation of workrooms was formerly based mainly on the dilution principle. In recent years, however, 50% of new investments in industrial ventilation in Scandinavia have been spent on displacement ventilation. Very little data exist from industrial settings on the relative performance of displacement ventilation versus dilution ventilation as regards air quality and thermal comfort. The present study collected data on the indoor climate in a sewing plant before and after the ventilation was changed from dilution to displacement.

The cabin of a commercial aircraft is a high density environment in which occupants are potentially at risk of airborne transmission of Mycobacterium tuberculosis. Trans-continental and trans-oceanic flights are routinely undertaken with hundreds of passengers. During these long flights there is an increased duration of potential exposure to airborne contaminants and bioeffluents. This paper determines a "worst case" risk of tuberculosis infection for the passengers and flight attendants based upon typical design and ventilation parameters of a commercial aircraft.