Volume Matching Control: Leave the Outdoor Air Damper Wide Open.
Volume Matching Control: Leave the Outdoor Air Damper
Seem, J. E.; House, J. M.; Klaassen, C. J.
ASHRAE Journal, Vol. 40, No. 2, 58-60, February 1998.
air flow; air handling unit; indoor air quality
Traditional air-handling unit (AHU) control systems link
the position of the exhaust air damper, recirculation
air damper, and outdoor air damper. This can negatively
impact indoor air quality if the exhaust air duct is
located near a pollution source. This paper presents a
new controls system for VAV AHU's that use volume
matching to control the return fan. The New control
system links only the position of the exhaust air damper
and recirculation air damper. During occupied times,
the outdoor air damper is in the fully open position.
Simulation laboratory, and field results are presented
to compare the new control system and a traditional
control system. The results demonstrte that the new
control system can prevent air from entering the AHU
through the exhaust air damper for conditions that cause
the phenomenon with the traditional control system.