Evaluating Control Performance on Building HVAC Controllers

Most controllers in Heating, Ventilation and Airconditioning (HVAC) applications remain the Proportional-Integral (PI) type. Poorly performing control loops is a common issue, resulting in wasted energy, reduced occupant comfort, and excessive and unnecessary wear of actuators. In this paper, different methods are evaluated for assessing the controller performance in HVAC applications. Each assement method is evaluated statistically using the simulation data from Modelica based heating and cooling coil models, which denote the good and two bad controls. Two performance indices are selected based on evaluations using the simulation data. These indices are further evaluated using real data from building HVAC control loops, which inlcude the hot water supply temperature control, hot water loop differential pressure control, room (served by VAV box) air temperature control, Air Handling Unit (AHU) supply air pressure control.