STUDY ON INDOOR THERMAL ENVIRONMENT AND AIR QUALITY OF OFFICE ROOMS CONTROLLED BY PERSONAL DISPLACEMENT VENTILATION USING CFD

摘要

Three-dimensional computational simulations are performed to examine indoor environment and micro-environment around human bodies in an office in terms of thermal environment and air quality. In this study,personal displacement ventilation (PDV), including two cases with all seats taken and two middle seats taken, is compared with overall displacement ventilation (ODV) of all seats taken under the condition that supply temperature is 24°C and air change rate is 60 l/s per workstation. When using PDV, temperature stratification, the characteristic of displacement ventilation, is obviously observed at the position of occupant's head and clearer in the case with all seats taken. Vertical temperature differences below height of the head are under 2°C in two cases with all seats taken, and the temperature with PDV is higher than that with ODV. Vertical temperature difference is under 3°C in the case with two middle seats taken. CO2 concentration is lower than 2 g/m3 in the breath zone.The results indicate that PDV can be used in the room with big change of occupants' number to satisfy the need of thermal comfort and air quality. When not all seats are taken, designers should increase supply air requirement or reduce its temperature for thermal comfort.