Experimental study of five different VAV air terminal devices under variable heat gain conditions in simulated office and meeting rooms

Demand control of the air distribution systems is crucial to satisfactory thermal environment under variable heat gain conditions in an energy efficient manner. In this study, airflow patterns, ventilation performance and local comfort have been experimentally investigated mock-up meeting office rooms with a volume (VAV) system. The Active Diffuser, which had constant inlet velocity, was compared some commonly used diffusers: Rectangular; Swirl-Radial; Swirl-Compact Multi-Nozzle Diffusers. test, there were four different levels: high (46 W/m2) room setting; W/m2), medium (24 low (11 setting, respectively. corresponding specific supply rates high, cases 4.3 L/s m2, 2.1 1 Visualized figures showed effect VAV on patterns quite among diffusers. indexes including effectiveness, effective draft temperature, draught rating so therefore analysed. By using most these more uniform stable VAV. Although Rectangular, Swirl-Compact, Swirl-Radial Diffusers might perform better one or two regarding indexes, their performances unstable Thus, Diffuser recommended for system application where gains vary significantly.