How an Air Conditioner Works

This First Air Conditioner

The first modern air conditioning system was developed in 1902 by a young electrical engineer named Willis Haviland Carrier.  The original system was develop to remove moisture from the air.  They discovered the side benefit was cooler air.  This is because cold air cannot hold as much moisture as hot air.  So moisture is removed and the air is cooled, both important factors for human comfort.

Air Conditioning Cycle

Today, our AC units are very efficient. They work by circulating a liquid from and outdoor location to an indoor location. This liquid is called a refrigerant and is contained in pipes. The liquid is pressurized and depressurized during its trip from the inside location to the outside location. This pressurization causes the liquid to lose heat and the depressurization causes the liquid to gain heat. So the liquid is what causes the heat out of your house and deposits the heat outside. This is a simplistic view but that is how it work.

The Compressor

The compressor is the device that pressurizes the liquid in the pipes. The compressor is located on the outside of the house or building and is housed within the condenser unit. The condenser unit is the big unit that sits beside the house. The compressor uses electricity to operate and compresses low pressure liquid (now actually a gas) to a high pressure liquid (soon to be a liquid). The conversion from gas to liquid doesn't happen right away, the pressurized gas actually needs to have a place to release the heat before it can turn into a liquid. This is done at the condenser coil. The condenser coil is an aluminium finned coil that also sites within the condenser outside. The last important item within the condenser outside is the fan, this is what helps the coil lose its heat to the outside air. Once the heat is removed from the high pressure gas, the hot high pressure vapor from the compressor turns into a high pressure liquid. Now the liquid is ready to go back for more heat within the house.

The Evaporator Coil

The Evaporator Coil is a aluminum finned coil within the house. It does the opposite as the condenser coil, it absorbs heat from the inside air. This absorbed heat is transferred into the our liquid and this causes it to become a low pressure vapor. It is now ready to go outside again and release this heat it gained.