Car Air Conditioning

How does car air conditioning work?

On hot days when it seems like even the air is boiling nothing can be as satisfying as sitting into your car and turning on the air conditioning. You may have wondered how your car air conditioner works. Car air conditioning systems all work on the same basic principles. There are three fundamental components of any vehicle air conditioner.

The Compressor

The compressor is essentially a pump which draws in the refrigerant gas from the system and concentrates it so that it takes up a smaller volume. This compressed gas is then pumped into the condenser.

The Condenser

The condenser exposes the heat of the refrigerant gas to air from your engine’s cooling fan or an electric fan. This causes the gas to cool down and it leaves the bottom of the condenser as a liquid under high pressure entering the evaporator.

The Evaporator

The evaporator is inside your car. Warm air from your vehicle passes over the evaporator and causes the liquid inside it to turn back into a gas. As it does so, it is able to absorb more heat which is transported outside of your car as the gas moves through the car air conditioning system. Excess water in the air will condense on the outside of the evaporator to dehumidify the air and will also attract dust and pollen. These materials are all drained out of your vehicle.

There are different kinds of Pressure-Regulating Systems in use in different models of car air conditioners.

a) Orifice Tube

Some air conditioning systems will use an Orifice Tube to regulate pressure. This device is located between the condenser and the evaporator and prevents too much refrigerant from entering the evaporator. Accumulators are used in these systems between the evaporator and the compressor so that water moisture and liquid refrigerant do not enter the compressor and damage it.

b) Thermal Expansion Valve

Other systems use a Thermal Expansion Valve to regulate the pressure within your car air conditioner. These car air conditioning systems may be connected to a receiver-dryer which ensure that only liquid refrigerant enters the valve. They also filter out dirt and moisture.

Using your car’s air conditioning requires energy, which makes extra demands on your engine and so decreases your miles per gallon, so to save fuel and money it may be a good idea to only use air conditioning in your car when you can’t get by with just an open window.