Diagnosis And Testing - A/C Performance Test: Notes
WARNING: This page is about a different car, the 2003 Dodge Intrepid, 2003 Chrysler Intrepid, 2003 Chrysler Concorde, and 2003 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.
The air conditioning system is designed to remove heat and humidity from the air entering the passenger compartment. The evaporator, located in the HVAC unit, is cooled to temperatures near the freezing point. As warm damp air passes over the fins in the evaporator, moisture in the air condenses to water, dehumidifying the air. High humidity reduces the evaporator's ability to cool the air. During periods of high heat and humidity, an air conditioning system will be less effective. With the a/c heater control set to RECIRC, only air from the passenger compartment passes through the evaporator. As the passenger compartment air dehumidifies, A/C performance levels rise.