Experimental Study of Thermal Environment and Comfort in an Office Room with a Variable Air Volume (VAV) System under Low Supply Air Temperature Conditions

The air distribution components in a variable air volume (VAV) flow system influences the overall function of the system. A low supply air temperature and a wide working range in terms of airflow rate, facilitate high energy efficiency. However, in order to achieve these properties, high demands must be set on the function of the supply-air diffusers.
This paper analyzes the thermal environment and comfort in an office room where the supply air diffusers have been chosen in accordance with such high demands. The study involves determining thermal comfort properties under different flow conditions and with a low supply air temperature, about +15oC, in a full scale test room. It also includes measured velocity profiles and calculated draught ratings. The results indicate that the risk of draught was quite low despite high airflow rates and a low supply air temperature with the studied type of a supply-air device.