How Does an Air Conditioning Compressor Work?

An air conditioning system is made up of four main parts: the compressor, condenser coil, evaporator and thermostat. The compressor is the first step in the cooling process. It is located outside of the home along with the condenser coil and houses the chemical refrigerant.

• A refrigerant is pumped into the sealed compressor at the factory. The refrigerant is a chemical, usually Freon, which can change from a gas to a liquid and back again quickly.


• The thermostat is programmed to turn on the air conditioning system when the room reaches a certain temperature. When the thermostat registers this temperature, it sends a signal to the compressor to turn on and begin working.


• The refrigerant, in the form of a cool gas, is pumped into the compressor where it is placed under a tremendous amount of pressure.


• The centrifugal compressor works like a fan by spinning its blades very fast. This forces the refrigerant to the edge of the blades where it is pressurized. The pressurization happens as the spinning compressor squeezes the molecules of the gas close together. This raises the energy and temperature of the gas until it becomes very hot.


• The compressor then forces the refrigerant in the form of a hot gas into the condenser.


• The gas flows through the condenser coils where it is transformed into a liquid. It then passes through the evaporator and is changed back into a gas.


• The cool gas is then pumped back into the compressor. This process repeats itself over and over again until the thermostat registers the correct temperature and signals the system to shut off.