Your vehicle’s air conditioning unit has six major components:
- The refrigerant carries heat. In modern cars, refrigerant is a substance called R-134a. Older cars’ refrigerant is called r-12 freon, which is more expensive and difficult to find than R-134a.
- The compressor circulates and compresses refrigerant within the vehicle’s cooling system.
- Your vehicle’s condenser changes the refrigerant from gas to liquid and expels heat from the car.
- The expansion valve (sometimes called the orifice tube) is a nozzle that simultaneously drops the pressure of the refrigerant liquid, meter its flow and atomize it.
- Your vehicle’s evaporator transfers heat to the refrigerant from the air blown across it, cooling your car.

