Air Conditioning

Click the links below for answers to some of our frequently asked questions.

What is a Free Pressure Check?
How does Air Conditioning work?
Are there Common Air Conditioning problems?
What is a "re - gas & do I need one"?
Can you do climate control?
Is my Air Conditioning working properly?
How much will it cost?

Free Pressure Check:

A quick and effective way to check your air conditioning is to measure the internal system operating pressures. We can do this while you wait, it takes no more than 10 minutes. We will also check the vent temperature and air flow at the same time. These procedures will give us a good indication of the health of your air conditioning and whether is it working correctly and efficiently. If there is a problem we can then conduct further tests if you wish to diagnose and quote for a service or repair.

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How does Air Conditioning Work?

(Click on the image for a larger PDF version )

The diagram illustrates the main components of a typical air conditioning system. When you or the climate control processor requests air conditioning a compressor driven by the engine engages via a magnetic clutch. The compressor pressurises refrigerant that flows around a sealed circuit of pipes. Using a valve the refrigerant is depressurised and evaporates in a heat exchanger causing it to become cold (around 0 deg. Centigrade). Air from the outside is passed through this cold heat exchanger and cooled before entering the vehicle. The cooling of the air causes it to lose water vapour and it becomes "drier" as well as colder – hence it is "conditioned".

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Common Air Conditioning problems.

The most common problem is loss of refrigerant. This can happen over time by unavoidable loss past compressor shaft seals and service connections. It can also be the result of a leak. The most common leak is from the "condenser", this is a heat exchanger in front of the normal engine radiator. The condenser is in a vulnerable position at the front of the car, it gets damage from stones, salt and other road debris and can fail at any time but most often after 4 or 5 years of service. Another common problem is clutch failure due to wear after 6 or 7 years of service.
Carwood have extensive experience of service, leak detection and repair across all vehicle types, please call us for a free system test.
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What is a "re-gas" & Do I need one?

The refrigerant in an air conditioning system is often referred to as the "gas", although it is sometimes in a liquid state. There is a correct amount or "charge" of gas for a particular system. It is possible that over time or due to a leak the refrigerant escapes. This means the system will be less effective or even cease to function completely. A "re-gas" replenishes the refrigerant charge to the optimum amount. The best way to do this is to remove any residual refrigerant, vacuum the system and recharge by weight. A "top up" can also be done in some circumstances. The only way to know if you need a regas is to have the system inspected and pressure tested, Carwood can do this for free, usually while you wait. Just give us call and drop in.
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Can you do climate control?

The simple answer is YES. Climate control has the same basic air conditioning components as any other system but with the addition of a computer and sensors to decide when to switch the heating and air conditioning on or off. Carwood can handle all types of system on all types of vehicles.
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Is my Air Conditioning working properly?

If your air conditioning is working it will provide a definite cooling effect. To test this turn on your ventilation blower to a medium setting, set the air distribution control to the centre face vents, set the temperature control to minimum (COLD) and turn on the air conditioning. After a few seconds the air should become noticeably cold, after a while of holding your hand in the air flow near the vent it should become uncomfortably cold. Please note that the engine must be running and the outside temperature needs to be over 10 degrees centigrade for the air conditioning to function. In any event, if you are not sure just give us a call and we will check it for FREE.
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How much will it cost?

Obviously it is impossible to say how much a particular vehicle will cost without a full inspection, but here is a guide for some common service or repair scenarios:

We will normally be able to give you a fixed price quotation after a full diagnostic inspection, this inspection is chargeable at £60 but will be waived if repairs are authorised and proceed.
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