How an Air Conditioner Works

Air conditioners work in much the same way that a refrigerator does; by cooling the air in an area while also extracting the hot air from the area and removing it from the vicinity. However, unlike a refrigerator, an air conditioner must do its job on an entire house, does not need to cool the air to the same degree, and it does so with some larger, more powerful equipment.

The process of understanding an air conditioner cooling system should start with an examination of the different parts of an air conditioning unit. Each and every air conditioner has three parts: a compressor, a condenser, and an evaporator. These three parts, in unison with a variety of chemicals that easily convert from liquids to gases and back again to liquids are what make all air conditioners work. It is essential that the fluid used in the air conditioner is in a gaseous state at room temperature.

Cooling an area with an air conditioner begins when the fluid in an air conditioner first enters its compressor in gaseous form. The compressor increases the gas pressure causing the molecules of the gas to collide until they are a high temperature and under significant pressure. This hot and pressurized gas then enters the condenser. Because this process creates so much heat, the compressor and the condenser in a home air conditioning unit are usually located outside of the home, to prevent the exerted heat from increasing internal temperatures. Heat is dissipated from the air conditioner's external unit by way of the exhaust fan and metal radiator fins.

As the gas leaves the condenser, the temperature is greatly cooled and because of the high pressure and the low temperatures, the gas turns to a liquid. The liquid then enters the evaporator through a very small hole which allows very little liquid to pass through at one time. In the evaporator, which is usually located inside the house (sometimes as an addition to a home's furnace), the liquid turns back into a gas and begins to evaporate. While it undergoes this evaporation process, it also extracts heat from the air, cooling it. The cooled air is then blown out of the air conditioner and is left to circulate throughout the house via ducts or other vents.

The gas which extracted the heat from the air then circulates back to the compressor as a low pressure gas where it can begin its journey through the air conditioning system yet again. This cooling process will continue until the built in thermostat on the air conditioning unit detects that the room is at the proper temperature.