The air conditioning (A/C) evaporator performs the following functions:

Refrigerant enters the A/C evaporator as a low pressure liquid. The low pressure causes the liquid refrigerant to become a gas (vaporize). This gas is able to absorb heat from the warm outside air that passes through the A/C evaporator fins. The cooled air is then directed into the passenger compartment. As heat is transferred to the A/C evaporator, moisture in the air condenses on the evaporator surface and is drained off carrying dust and pollen. A water drain port is located at the bottom of the evaporator housing. The temperature of the A/C evaporator must be high enough so that the surface condensation does not freeze and block off any air passages. The temperature of the A/C evaporator is regulated by both the A/C expansion valve and the thermostat. The A/C evaporator is located in the heater module, under and behind the instrument panel.