Variable-air-volume air-conditioning system under reduced static pressure control

A field experimental study on the performance of a VAV system having a variable speed drive for fan motor under reduced static pressure control has been carried out. Direct-digital-control VAV boxes and network communication technology were applied in the study. The supply fan speed was adjusted to its lowest possible level using summation of airflow passing each VAV box as the control signal. The results confirmed that more fan energy can be saved if duct static pressure is allowed to be reduced as compared to the requirements of fixed static pressure control algorithms, and when a VAV system is operated in lighter load condition under reduced static pressure control.