Patent ID: 6298912
Filing Date: 2001-10-09
Classification: F24F

Abstract:
A system for conditioning air in a plurality of zones, comprising:a heating, ventilating, and air conditioning unit having an economizer operable to allow variable amounts of outdoor air into the unit, the unit operable to provide conditioned air to one or more zones;a supply air duct connecting said unit to said one or more zones;a damper associated with each of said one or more zones, the damper operable to control the amount of conditioned air entering each of said one or more zones;a return air duct connecting each of said one or more zones to said unit and returning air to said unit;a bypass duct connecting the supply duct to the return duct;a first temperature sensor for sensing a first temperature representative of the air returned to said unit;a second temperature sensor for sensing a second temperature representative of the outdoor air; anda main control, coupled with said temperature sensors, operable to modulate the economizer to increase the amount of outdoor air entering said unit when the first temperature falls below a cooling setpoint, the second temperature is greater than the first temperature, and the unit is operating in a cooling mode, the control further operable to modulate the economizer to increase the amount of outdoor air entering said unit when the first temperature rises above a heating setpoint, the second temperature is less than the first temperature, and the unit is operating in a heating mode.