Analyses of the Energy Performance of VAV System with Different Control Strategies

VAV system has been applied broadly due to the eminent energy-saving and thermal comfort characteristic. Sophisticated control systems are required to support their operation. Different control strategies make different effects to the building energy performance. This paper analyzes several common VAV control systems, including air flow control at the room level, air flow control at the AHU level, supply air temperature control, generator control, control of distribution pumps, and defines baseline control strategy and improved control strategy for each system. Simulation environment was established with TRNSYS for six different control strategy combinations, so as to evaluate the energy performance of these control strategies. The result shows that air flow control at the room level and control of distribution pumps make great effect to energy consumption of HVAC system, while the supply air temperature control and chilled water temperature resetting have relatively smaller effect.