Simulation on uniformity of supplied air from plenum chamber of underfloor air distribution systems

Establishes a model of underfloor plenum chamber, simulates and analyses the influences of the height of plenum chamber and the density of air supply outlets on the uniformity of supplied air. Uses the imbalance rate of supplied air as the uniformity evaluation index of supplied air with underfloor plenum chamber. The results show that the air supply uniformity of plenum chamber gets better with the increase of plenum height, so there is a minimum plenum chamber height which gets smaller with the decrease of the density of air supply outlets. The air supply uniformity gets worse with the increase of the density of air supply outlets. The distance between air supply outlet and air inlet in plenum chamber impacts both the minimum plenum chamber height and the air supply uniformity, and the distance should be kept in a reasonable value in project design.