by Adam Feneley

Created on: April 17, 2009

How to Fix a Cars Air Conditioning:

Air conditioning systems can vary quite alot from car to car. To learn how to fix your air conditioning system and figure out what is wrong with it you need to know how it works, a very good way to understand this better is follow it through with your cars manual and a comprehensive diagram, like the one shown here

There are three major types of air conditioning systems in modern cars, all of which have a very similar design and concept and as such can be explained as one. Your air conditioning system consists of a compressor, condenser, evaporator, orifice tube and a receiver-drier. In some systems you may have a thermal expansion valve instead of an orifice tube, and either a receiver drier or accumulator, as each these are effectively variations of the same component, you will have one of each.

The compressor is a belt driven pump which is run by the engine, it compresses and transfers refrigerant gas (such as Freon in older cars see this article for more details) The air conditioning system works strangely like a heart with half of it under high pressure and half under low pressure, (discharge and suction). The intake side draws the gas from the evaporator (in some cars via an accumulator), it is then compressed and sent to the condenser.

Ususally just in front of the radiator in your car you will your condenser. The condenser looks just like a car radiator and is where the heat dissipates. Hot compressed gases enter the condenser and are cooled and leave as a high-pressure liquid.

The primary function of the evaporator is to remove heat from inside a vehicle as well as dehumidifying the air. Warm air enters the evaporator coil and condenses on its surface, on humid days you can see this dripping from the bottom of your car, this is normal so don't worry if you notice this! The evaporator operates best at 32 degrees F (zero Celsius), meaning when refrigerants enter as liquid and meets the warm air it begins to boil (as these gases have a very low boiling point) at this point the refrigerant absorbs a lot of heat from the car and it is carried away, cooling down the car.

Pressure regulating devices are used to control the pressure and subsequent temperature of the refrigerants; either the Orifice tube or the thermal expansion valve does this job. A TXV (thermal expansion valve) is a valve sensitive to pressure and temperature, they are efficient but can suffer from clogging and corrosion. Whereas an orifice tube (commonly found

• 1
• 2
• Next Page >>