How the A/C system works

Step One: When the A/C system is turned on, the compressor 'compresses' the refrigerant vapour heating it up and pumps it under high pressure to the condenser

Step Two: The hot vapour from the compressor arrives and the fins help the air flowing through the condenser remove heat from the refrigerant, changing it to a much cooler liquid state. When the car is stationary the radiator cooling fans perform the task of moving air through the condenser.

Step Three: Refrigerant moves to the receiver-drier. The primary function of the receiver-drier is to separate gas and liquid. The secondary purpose is to remove moisture and filter out dirt.

Step Four: As the compressor continues to pressurize the system, cool liquid refrigerant under high pressure is circulated from the receiver-drier to the expansion valve. The expansion valve allows liquid to pass through a very small orifice, which causes the refrigerant to expand to a low-pressure, low-temperature gas. This "cold" refrigerant flows to the evaporator.

Step Five: As the cold low-pressure refrigerant is released into the evaporator, it vaporizes and absorbs heat from the air in the passenger compartment. As the heat is absorbed, cool air will be available for the occupants of the vehicle.

Step Six: The low-pressure refrigerant vapour is then drawn into the compressor to start another refrigeration cycle.