How Air Conditioning Works on a Car
Air conditioning has become a standard feature on most vehicles with a staggering 99% of new cars having it included. Even though it is regarded as a relatively new addition to cars, the first automaker to offer AC for a factory car was actually Packard in 1940. Of course, the cooling unit found in today’s modern cars is wildly different from that one, starting with the refrigerant used for it. The original one, called Freon, was revealed to be very harmful to the ozone layer so it was banned and discontinued from being used for American cars and a safer refrigerant became mandatory in 1996.
Despite these changes, the principle behind the air conditioning unit remains the same – it cools the air and removes humidity. This is accomplished through the three major components which are part of every AC unit – the compressor, the condenser and the evaporator.
The Cooling Process
The compressor is a pump which is powered by a belt attached to the crankshaft of the engine. Its role is to draw in the refrigerant, compress it under gaseous form and release it through the condenser. It is only capable of dealing with gases and would not be able to handle any water which gets into the process by accident. That is why there is a little tank installed next to the compressor known as the receiver-dryer. Its goal is to attract any water trapped in the loop and remove it from the system in order to prevent any damage to the overall air conditioning unit.
Once the refrigerant is expelled from the compressor under pressure, it enters the condenser which basically acts as a radiator and removes heat out of the system. While the refrigerant is in the condenser, it is cooled down to the point where it transforms into liquid form again, but under high pressure.
The last component is the evaporator which, unlike all the others, is not located in the engine compartment, but rather inside the cabin of the vehicle. It has a series of coils and tubes through which the refrigerant will pass with the goal of absorbing the heat in the cabin. At the same time, the heat absorbed is enough to transform the refrigerant into a gas again due to its low boiling point. Once this happens, the refrigerant is reused and the process starts all over again.