Car Air Conditioning Service: All You Need to Know

10th Feb 2021

By Nathan Dale

Look after your car's air conditioning system

Car air-conditioning is a feature we've come to expect in the vast majority of new cars that are on the market. However, you may not realise that air-conditioning requires regular maintenance just like the rest of the vehicle. In fact, you may not even know how it works at all.

How does air-conditioning work?

Air conditioning service diagram

Your car's air-conditioning system is comprised of five integral parts:

  • Refrigerant (the gas)
  • Compressor (which contains the refrigerant)
  • Condenser
  • Receiver
  • Thermal expansion valve
  • Evaporation coils

When the air-conditioning system is activated, the refrigerant (gas) travels to the condenser. Fresh air from the atmosphere passes over the condenser, which causes the gas to drop in temperature and become a liquid.

That liquid passes through a receiver, which removes impurities, before reaching a thermal expansion valve. The valve allows you to control the temperature by adjusting the flow of the liquid. The liquid is then turned into a vapour as it passes through the evaporation coils, which subsequently gets blown into the cabin as cool air. The refrigerant has become a gas again by this point, and returns to the compressor ready for the process to start all over again.

How often does my car's air-conditioning need re-gassing?


The general rule of thumb is that your vehicle's air-conditioning needs re-gassing every two years. The reason for this is because it's estimated that your car permeates between 10 - 15% of gas from the system every year; and that's before you've even used it!

An air-con service also presents a good time to get the system de-bugged, which essentially decontaminates the whole system. This is recommended because aspects of the air-conditioning system are a breeding ground for bacteria, which in turn leads to bad odours.

Note: Ignoring a bacteria build up in your air-conditioning system can potentially have an adverse affect on allergies.

How much does it cost to re-gas my car's air-conditioning?

Maintaining your vehicle's air-conditioning system is actually very reasonable:

Air-conditioning check - FREE

Air-conditioning Anti-bacterial clean - £20

Air-conditioning re-gas - From £49

Explore Air Conditioning Services

Air conditioning FAQs

Technicians inspecting air conditioning system

Where can I get my air-conditioning re-gassed?

Evans Halshaw boast a large number of retailers across the United Kingdom, all of which have specially trained technicians on-site that can check and re-gas your vehicle's air-conditioning.

How long does it take to re-gas my car's air-con?

It usually takes around 45 minutes to complete a re-gas on your vehicle's air-conditioning system if it is fault-free.

Why isn't my air-conditioning working?

There's a list of reasons your car's air-con may not be working, but the most likely cause is that there is no gas in the system. Alternatively, there is a leak somewhere and the system needs checking over by a trained technician.

Can I re-charge my air-conditioning at home by myself?

No - a mandatory qualification is required by anyone wishing to service the air-conditioning on a car, this is because of the potential hazards involved with the refrigerant, which needs disposing of properly.