Abstract
Displacement ventilation system(hereafter D.V.) can make indoor air quality better than conventional mixing ventilation(hereafter M.V.) does and can also save energy for HVAC. Generally, the required ventilation flow rate of D.V. is designed same as M.V. and supply air temperature of D.V. is higher than M.V.. When supply air temperature of D.V. is low, fan operating energy can be reduce, furthermore, duct size can be compact. However, when air diffusers designed for small under-temperatures supply low temperature, draught along the floor occurs in the occupied zone and thermal condition would become worse. In this paper, a full-scale experiment in a laboratory on D.V. was presented. The distribution of temperature was discussed with the experimental results. Several factors were investigated, i.e. discharged height of supply air and large under-temperatures, such as ambient air and low supply air temperature.
