Volume Matching Control: Leave the Outdoor Damper Wide Open PDF

Presents simulation, laboratory and field results which demonstrate that air can enter an air handling unit (AHU) through the exhaust air outlet of a traditional volume matching control system. Describes a new control system for variable air volume AHUs that uses volume matching to control the return fan. The aim is to prevent outdoor air from entering an AHU through the exhaust air outlet. The new control system links the position of the exhaust air damper and recirculation air damper, while the outdoor air damper is in the fully open position during occupied times. Traditional AHU control systems link the position of the exhaust air damper, recirculation air damper and the outdoor air damper. Notes that the new control system will not prevent reverse airflow for poorly designed AHUs operating under extreme conditions.