How it Works
Here's how an air conditioning system and its components work.
Compressor: The compressor is the power unit of the A/C system. A drive belt connected to the engine’s crankshaft powers it. When the A/C system is turned on. The Compressor compresses the refrigerant from a Low pressure Refrigerant Vapour [suction] to a High Pressure Vapour [discharge] this High-pressure vapour is passed from the compressor to the top of the Condenser.
Condenser: The condenser is a device used to change the High-Pressure Refrigerant Vapour to High Pressure Liquid. It is mounted ahead of the engine's radiator, and it looks very similar to a radiator with its parallel tubing and tiny cooling fins. If you look through the grille of a car and see what you think is a radiator, it is most likely the condenser. As the car moves, air flowing through the condenser removes heat from the refrigerant, condensing to and changing it to High Pressure Liquid. This High Pressure Liquid is them passed to the:-
Orifice Tube: Where the High Pressure Liquid drops in Pressure and Temperature to Cold Low Pressure Liquid, which is then passed to the:-
Evaporator/Cooler: [which is inside the cab] The Refrigerant takes up the warm air in the cab via the cooler coils and the Evaporator fans blows the cold air into the cab. The Refrigerant inside the evaporator is now being turned back to a Low Pressure Vapour, but still contains some liquid. This mixture of refrigerant now passes into the Accumulator/dryer This can also acts as a 2nd Orifice as any excess liquid is “Boiled off back to pure Low Pressure Vapour, before it is allowed to pass back to the compressor ready to e pumped around the system again. If fitted with silicon it will also removes moisture from the refrigerant.
In some systems instead of an Orifice Tube being fitted. The system uses a Expansion Valve
Expansion Valve: The expansion valve, which is normally factory set to the Air Conditioners manufacturers’ specification, is probably the most important component in the system. It is designed and pre-set to control the flow of liquid refrigerant via its orifice valve which allows expansion from liquid to vapour (hence its name) as the refrigerant leaves the expansion valve and enters the evaporator, Vast problems will happen if the orifice is allowed to block up with foreign matter
Evaporator: The evaporator is very similar to the condenser. It consists of tubes and fins and is usually mounted inside the passenger compartment. As the cold low-pressure refrigerant is released into the evaporator, it vaporises 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. A blower fan behind the dashboard helps to distribute the cooler air.
As you can see, the process is quite complex. Just about every vehicle's A/C system works this way, though certain vehicles might vary by the type of components they have.