Leaving air temperature control of cooling system

摘要

The temperature of air leaving a cooling coil is monitored for dropping below various threshold values. The number of cooling stages which chill the refrigerant flowing through the cooling coil is first reduced when the temperature drops below a first threshold and continues to drop relative to a previously sensed temperature. Damper positions governing the amount of air flowing to zones to be cooled are thereafter adjusted when the temperature continues to drop relative to a previously sensed temperature. All adjusted positions are at least maintained relative to a calculated offset value until the temperature rises above a second threshold value greater than the first threshold value. All cooling stages are turned off if the sensed temperature drops below a third threshold value lower than the first threshold.