Vehicle air conditioning is one of those things that people don’t tend to think about until it’s no longer working.  Here at TWG Automotive we have the latest in air conditioning technology in order to keep your car’s aircon running cool all year round.

What many people do not realise is that their aircon systems should ideally be professionally serviced every 2 years.  This enables you to keep ahead of system faults or potential compressor failure.  An added advantage is that a well maintained system operating on the correct amount of oil and gas will enhance your compressor’s capacity to run efficiently, which aids fuel consumption.

How does air conditioning work?

The engine drives a compressor that draws the refrigerant gas pipe from the evaporator and compresses it to a high pressure.  The gas heats up and, still under pressure, is piped to the front of the car where it is connected to the radiator.  As cold air passes through the radiator it cools the gas sufficiently to turn it into a liquid.  The liquid, which is still at high pressure, comes out of the condenser at the bottom of the radiator and is piped back towards the cabin of the car where it enters into the heat exchanger through a restriction like a pin hole.  It is squirted in a fine spray into the heat exchanger (evaporator). This fine spray is now in an area of very low pressure so the tiny droplets now have the room to expand and turn back into a gas. To do this they have to absorb some heat, which they take from the cabin thereby creating a feeling of cold.

If for any reason there is insufficient air passing through the condenser then the gas will remain as a hot, high-pressure gas and will complete the circuit back to the compressor and there will be no cooling so it is important that the cooling fans are operating properly. Fans have a finite life and eventually need replacement.   A fan that may not have had to do any work for a while because the refrigerant has run down may easily seize up and refuse to work again, a situation that has been known in some BMWs.

When you switch the aircon on a sensor checks there is sufficient refrigerant in the system to not damage the compressor and, if there is, it allows 12 volts to flow to an electro-magnetic clutch on the compressor.  It is normal for the system to have other sensors to monitor for excessively high pressures and to turn off the compressor to avoid the possibility of damage.

The temperature of the evaporator is usually maintained at just over freezing point either by a thermostat or by a switch or a valve that controls the pressure. The cold air may now be blown in to the vehicle and you will feel the advantage of coolness on a hot day or demisting on a cold wet one.

Vehicle air conditioning systems are a specialist field

There are now a number of rules, regulations and guidance covering the correct handling of R134a, the gas inside your aircon system, and here at TWG our technicians are F-Gas trained and run the latest AC equipment to ensure we comply.

Air Con Recharge for your BMW or MINI Vehicle

In hot weather, aircon keeps you comfortable; in cold it is an integral part of your demisting system, essential for keeping you safe.  Therefore, if your aircon system has stopped working it is important to deal with the as quickly as possible.  Leaving it for too long not only compromises comfort and safety, it can also lead to more expensive problems.  For example, if the inside of the AC system becomes exposed to the atmosphere because of leakage or damage, the system can take on moisture which is detrimental to all of the AC components, which may then need repair or replacement.

When we service an air con system we will:

  • Drain down old air con gas, in compliance with the European Regulation 842/2006/EC
  • Complete a full vacuum test of system to identify any possible leaks and assist in removing moisture
  • Where leaks are identified we test the system with nitrogen free oxygen, as required by law
  • Once secure, the aircon system is refilled with the correct amount of R134a refrigerant gas
  • Inject new PAG oil into the system for long term maintenance
  • Inject aircon UV dye into the system to aid the detection of future leaks
  • Print out a full aircon service report stating the amount of R134a recovered from the system; the status of the vacuum test; the quantity of PAG oil used; that UV dye has been used and the quantity of R134a refilled into the system

The price for an AirCon regas is £65.00 icluding VAT, call now to get your car booked in.