Car air-conditioning systems are intricate networks made up of numerous essential components. Learning how each stage of the cooling process works can be useful knowledge if your air-conditioning breaks down.


The compressor is the heart of your air-conditioning system. It’s a pumping unit that’s used to circulate the refrigerant and pressurise the high side of the system. A compressor, just like a heart, needs a good diet of essential oils and the right level of gas (life blood) to keep it from prematurely burning out.


The condenser functions like a radiator, extracting heat from the pressurised refrigerant and converting the gas into a liquid. The condenser features an electric cooling fan and is also located at the front of the vehicle, next to the main radiator.

Thermal expansion valve

The thermal expansion valve reduces pressure on the refrigerant, allowing it to expand and revert to a gas when entering the evaporator. This valve also controls how much refrigerant flows through the evaporator at any time, to offer precise temperature control.


Refrigerant flows through the evaporator and removes the heat of the air passing over it, which enters the cabin and provides a cooling effect. The cool refrigerant vapour is then drawn back to the compressor to start the cycle again.


The drier, also known as the accumulator, uses a desiccant to draw moisture out of the system. Water can cause serious damage to air-conditioning systems by freezing into ice crystals at the thermal expansion valve or mixing with the oils and refrigerant to cause a corrosive effect on the aluminium components. The receiver-drier also contains a filter that stops any metal particles that might fragment from the compressor from flowing through the whole system.

Car repairs in Brisbane

Mr Cool is dedicated to providing the best air-conditioning service in Brisbane. Speak to their friendly and experienced technicians about all automotive air-conditioning issues by calling 07 3188 4348.