The heating system consists of hot coolant from the engine, a heater core and a blower motor. The A/C system consists of an A/C compressor, condenser, evaporator core, expansion device and receiver/drier. The heater removes heat from the cooling system and adds it to the passenger compartment. The A/C system removes heat from the passenger compartment to outside the vehicle.
In order for the heater to function, hot coolant passes through the heater core. Cool air is blown through the heater core and heat is transferred from the heater core to the air. The heated air is then circulated through the desired vents and into the passenger compartment. The small tubes and fins of the heater core create a large surface area for the air passing through the heater core.For the A/C system, freon gas is compressed by the A/C compressor. The high pressure gas is then changed to a high temperature liquid inside the condenser as air blows through the condenser. The liquid then moves to a metering device. As it passes through the metering device to a lower pressure, the liquid evaporates and cools. This cool gas then passes through a series of coils also known as the evaporator core. After passing through the evaporator core, the low pressure freon gas returns to the compressor. The blower motor blows air through the cold evaporator core, removing the heat from the air. This cool air is then directed to the desired vents and into the passenger compartment.