Heater, Ventilation, And Air Conditioning System Operation

The A/C system provides the following features:
^ Cooled or dehumidified air for the comfort of the occupants
^ Power ventilation
^ Windshield defrosting
^ Side window defrosting

During most operating conditions, outside air enters the vehicle in the following manners:
^ The blower motor pulls in outside air through the heater and air conditioning modules.
^ The forward movement of the vehicle forces in outside air.

Air is pushed by the blower motor, along the following path:
1. Through the evaporator core
2. Through the heater core
3. Into the passenger compartment

If the ambient temperature is above 7°C (45°F), the refrigeration system will chill the evaporator to almost freezing. This action permits the operation of the following components:
^ The air conditioner
^ The defroster

As the air passes through the evaporator, the air temperature drops. Air moisture condenses on the evaporator core fins. A gravity feed through a drain hole removes the moisture from the vehicle. This action dehumidifies the air.

From the evaporator, some or all of the air may pass through the heater core. If the system is in the heating mode, the engine coolant warms the air. Any of the air which is not to be heated will mix with the heated air before entering the passenger compartment.

If the user selects the maximum air conditioning mode, most of the air that enters the blower motor is from the passenger compartment (recirculated). The air from the passenger compartment is usually cooler than the outside air. The other modes use outside air.