Air Conditioning and Heating

Air Flow:

The heater, ventilation and air conditioning system operates on the reheat principle in which all the air passing through the system is chilled almost to a freezing temperature and then reheated to a more comfortable temperature before it is discharged into the passenger compartment. Chilling the air in this manner condenses most of the moisture out of the air, dehumidifying it for occupant comfort.

The dehumidified air is reheated as it passes through the heater core in the heater and air conditioning evaporator module assembly. The heater is warmed by engine coolant passing through the tubes of the heater core. This heat is transferred to the heater core fins and given off to the air flowing past the fins.

The position of the temperature valve in the heater and air conditioning evaporator module assembly determines how much of the total airflow is allowed to pass through the heater. In turn, this determines the warmth of the total airflow discharged into the passenger compartment.

The heated engine coolant supply for the heater comes from the heater hose fitting in the inlet manifold near the ignition distributor.

The inlet heater hose assembly, containing the heater water flow control valve assembly is connected to the inlet fitting of the heater core by a quick connect fitting. The heater inlet hose assembly contains a calibrated restriction that limits water flow to the heater core.

Hot engine coolant from the engine's cooling system is directed through the heater core and returned to the cooling system by the heater outlet hose when the engine is running.

The heater outlet hose returns the heated engine coolant to the engine coolant thermostat housing assembly then to the radiator assembly.