Air conditioning is not all about cooling down the temperature, but also reducing humidity or moisture content. Air conditioners function in the same way, whether they are installed in a car or in a building. The main principle behind its operation is evaporation and condensation, followed by compression and expansion.
The fluid passing through the entire system is the refrigerant that evaporates at a low temperature, and condenses again at higher pressure. R-12 was the refrigerant that was generally used earlier. But it was found to be damaging the ozone layer of the earth, being a chlorofluorocarbon. After discontinuation of its use, all cars started using R-134A refrigerant, which is safer for the environment. Getting back to our main topic, let us see what are the different parts of a Porsche AC system.
The compressor is the main working force behind any air conditioning system. It is powered by a drive belt, linked to the engine’s crankshaft. The refrigerant vapour is pumped by the compressor under high pressure, when the aircon system is turned on.
The high-pressure refrigerant is turned into a liquid, by the condenser. It bears a resemblance to a radiator, and is also positioned in its front end. Given the high pressure driving it in, the vapour is condensed into a liquid, generating a great amount of heat. The heat is then eliminated from the condenser by the flow of air through the condenser.
The liquid refrigerant makes it way to the receiver-dryer. For the liquid refrigerant, there’s a small reservoir vessel. Any moisture is eliminated that may have seeped into the refrigerant. Moisture can be dangerous for the system, causing havoc with ice crystals leading to mechanical damage and blockages.
There is a flow of pressurized refrigerant from the receiver-dryer to the expansion system. It can be anything like an expansion valve or an orifice tube, where the liquid refrigerant expands and becomes vapor in the evaporator.
This is another device that bears resemblance to a car radiator. It has fins and tubes, and is generally mounted within the passenger compartment. As the refrigerant (cold low pressure) passes into the evaporator, vaporization and absorption of heat takes place from the atmosphere. The blower fan propels air over the evaporator’s exterior, so cold air is dispersed inside. There is a reduction in the air moisture on the ‘air side’ of the evaporator, followed by collection and draining of the condensate.
For the refrigerant leaving the evaporator, there is a holding tank known as accumulator. With the circulation of refrigeration inside, the accumulator desiccant bag takes out any moisture that may have developed.
Another refrigeration cycle starts with the compressor drawing in the low-pressure refrigerant vapour. The cycle keeps running continuously, and is regulated by the expansion valve’s setting.
The entire process is quite simple, with each component functioning in the same manner as other air conditioning systems. Make sure to carry out regular maintenance and servicing for smooth functioning of the car’s AC.