A Robust Control Strategy for VAV AHU Systems and Its Application

Abstract

The paper demonstrates a robust control strategy for variable air volume (VAV) air handling unit (AHU) systems which are commonly used in office buildings. Compared with traditional VAV AHU control adopting constant the setpoints of static pressure and supply air temperature, the strategy is composed of two independent modules, static pressure reset control and supply air temperature reset control. The optimization is realized by identifying optimal static pressure setpoint and supply air temperature setpoint to achieve predefined thermal comfort standards. The thermal comfort standards can be customized based on the practical operation performance through altering related parameters to tolerate unavoidable defects in real VAV AHU systems. The strategy was developed into software and applied in AHU systems of an office building located in Hong Kong. Its control performance was evaluated with respect to energy saving and indoor thermal comfort maintenance and proved to be effective.