Car air con
I know that we have all seen and heard this weather warning in the past and nothing ever comes of them, especially from the “Daily Express” newspaper group. This warning from the “Daily Mirror” is of a heat wave that may last up to two weeks; nice if it happens.
I did think though that it was about time I did an article about your CAR AIR CON (air conditioning system). In my opinion, it is always a good thing to remind our customers that it is
important to have your air con system checked out and serviced.
Car air con in winter
Many drivers make the mistake of turning their car air con off in winter. I appreciate that with it on the car uses slightly more fuel, but the truth is that when it is switched off, and then the parts of the car air con system are not being used and will deteriorate. The parts and hoses are often made of rubber and plastic and because it is a sealed system, you are likely to get a loss of pressure due to leakage and this leads to the system failing with the car air con system not working and probably leading to a more expensive repair. Some of our customers think that the heating system will not work with the air con switched on, but this is not so, the car will be hot or cold with the air con in winter and summer.
How does your air con work?
Basically, all car air con systems work in a similar fashion. It operates by taking a gas known as R134a refrigerant and pressurize it in a sealed system using a compressor. As the system is pressurized it heats up by absorbing the air around it. The hot gas is then passed through a series of tubes, similar to a car radiator which dissipated the heat.
The gas loses its heat and gets really cold by turning into a liquid, this is the stage when the cold air is blow into the cars cabin and cools you down.
Some of your cars air con component parts
At the very heart of your air con system is the compressor. The compressor is the part that takes the R134a refrigerant gas and pressurizes it to cool the air. The compressor is operated by an engine belt but has also had an electric clutch system that controls the demand for colder air, in other words, the compressor will turn on and off as you demand colder air in the cars cabin.
The next part to explain about is the Condenser. The condenser is mounted at the front of the car next to the main car radiator and is usually smaller in size. This is the part that converts the gas into a liquid as it becomes cooler, just like the radiator cools the water down that comes red hot from the engine, a similar principal.
The next part is like a small radiator and is called the Evaporator. The evaporator does exactly opposite to the condenser and super-cools the liquid as it passes through the tubes. At this stage air is forced through and into the cars cab, super cooling the cars interior to the delight of the occupants on a hot sunny day. As the gas cools down again it is turned back into a
liquid and the cycle starts over again.
Another important part of your car air con is called the thermal expansion valve.
The expansion valve controls the flow of the super-cooled refrigerant to the evaporator; this equipment helps to regulate the cold air that ends up in your cabin. The next part of the car air con system to mention is the accumulator also known as the “drier”. The drier protects the compressor from damage that may be caused by any liquid that makes its way back and could damage the compressor. It does this by a chemical process that absorbs any moisture to the system, it also acts as a filter catching any small pieces of rubbish that may have made its way into the system.
That just about covers the general idea of how your car air con system works without trying to get too complicated. Cars have all got different variants and are fitted with sensors to pick up temperature and differences in pressure, but most Old Cars work off a similar system. Toyota Cars have a different system to say BMW cars.
We at Pellon Auto centre here in use a Sun-air con machine to service the cars with and what it does is to recirculate the gas and add more if required and then re-pressurizes the system. Many cars loose pressure because they have not had their air con switched on in winter and the system has lost pressure, but most servicing machines can find a fault and we use a special spray to find any possible leaks in the cars system.
Hope this air con advice was of use to you
Pellon Tyre and Auto centre offer car and van servicing and repairs to all makes of vehicles. We are members of Unipart Car Care centres and give a nationwide guarantee for all our work and parts. We also sell tyres online from our website www.pellontyres.co.uk