The air quality at the breathing zone with displacement ventilation.

This paper presents the difference in the air quality between that perceived by the occupants (breathing zone) and that in the occupied zone as a whole. An environmental chamber with displacement ventilation system has been used to carry out the measurements with the presence of a heated mannequin and other heat sources. Measurements of the age of air distribution, the air exchange index and the ventilation effectiveness were carried out at different points in the chamber for different room loads. CFD simulations were also carried out for the purpose of flow visualisation as well as the calculation of air velocity, temperature and age of air distribution. The results from the CFD simulations were compared with those from measurements.