Floor-supply displacement air-conditioning: Laboratory experiments

The results of laboratory measurements on the performance of a floor-supply displacement air-conditioning system in comparison to a displacement ventilation system with a side-wall-mounted diffuser and a ceiling-based distribution system are described. Thermal stratification was observed, as there were greater vertical air temperature differences in both of the displacement systems than in the ceiling-based system. The floor-supply displacement air-conditioning system produced a uniformly low air velocity at each measurement height, while a rather high air velocity near the floor was observed for the displacement ventilation system with a sidewall-mounted diffuser. Local mean age of air of the floor-supply displacement air-conditioning system was lower than that of the other systems, especially in the lower part of the room. According to the simulation results, the floor-supply displacement air-conditioning system with outdoor air cooling requires 34% less energy than the conventional air-conditioning system with outdoor air cooling.