Regassing and maintaining your car air conditioner

Replacing the gas in your air conditioner, known as re-gassing, is one part of the service and maintenance of your car’s air conditioning system but it’s not the only thing that needs to be attended to in order to keep your air conditioner in good running order.

Due to the constant pressure the components which make up your car air conditioning system are under, they need to be well maintained. Over time, leaks will occur and the refrigerant gas will begin to leak. Other parts of the system will also wear and need replacement.

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Gas leaks can occur when the hoses and seals that the gas and liquid refrigerant pass through begin to age and wear. As this happens, gas will slowly begin to leak, and your air conditioner will become less effective.

Signs that your car air conditioner may need a regas or service:

• It is no longer cooling effectively

• The system is noisy when switched on

• There is an odour coming through the vent when the system is operating

A musty smell coming from the vents in your car when the air conditioner is switched on can indicate the presence of mould either in the cabin air filter or elsewhere in the air conditioning system. It’s important to get this attended to, especially for those who suffer from asthma or other respiratory conditions.

If you notice the air is not as cold as it once was, it is highly likely that your car’s air conditioning system needs at least a regas, and probably a good check-over in general. A noisy system may indicate other parts need repair or replacement.

As part of a service, a leak test will be conducted to determine if there is a gas leak and where it is coming from.

If your car does need a regas, the old gas will be removed, any maintenance done, and new gas will be pumped in.

How much does a car air conditioner regas cost?

RAC Auto Services can perform an air con regas from $198* or you can add an air con service to an Essentials (minor), Essentials Plus (major) or logbook service for $129*. The service includes testing the full operation of the system, leak inspection, a regas, drive belt and compressor check and a sanitisation treatment.

Using your car air conditioner more effectively

Open some windows when you first get into a hot car to release some of the heat so your air conditioner won’t need to work as hard.

Use the recirculation mode on your ventilation controls for a few minutes after you start driving to get the air in the cabin to cool quickly. Then switch it off. If your car has stop/start technology, you might find this functionality working less often due to the engine needing to continue to run the air conditioning compressor.

How your car air conditioner works

Your car’s air conditioner is not so much one unit, as a system of connected components that push a refrigerant gas through a complex process involving high heat and high pressure. This process turns the gas into a cold liquid and then back into a gas in order to produce cold air.

Keeping your car air conditioner in good working order will not only keep you more comfortable in your car but it can also keep you safer, because the air conditioning system helps defrost your windscreen.

Compressor

When you turn on your car’s air conditioner, a pulley being driven by the engine is engaged with the air conditioning compressor. When this happens, refrigerant gas inside the compressor is compressed to a very high pressure and high temperature and then passes through a hose that connects the compressor to the condenser.

Condenser and dryer

The condenser looks a little like a radiator and is located at the front of your car. The gas coming from the compressor goes through the coils in the condenser, reducing the temperature of the gas which also turns it into a liquid. Once in liquid form, it flows through to a unit called a dryer that functions to ensure there is no more gas present.

Thermal expansion valve

From the dryer, the liquid then travels to the thermal expansion valve. Once it flows through the valve, the liquid refrigerant turns back into a gas at which point the temperature drops. Now you’re getting closer to getting some cold air flowing through to the interior of your car.

Evaporator

The next step sees the gas go through an evaporator, which, as with the condenser, resembles a small radiator. It travels through the coils of the evaporator and from there it meets your car’s fan where it cools any warm air passing through the fan resulting in cool air flowing through into the cabin of your car.

The now cold gas from the evaporator then travels back down to the compressor where it began its journey and the whole process is repeated.

Last updated: October 2022