How does air conditioning work?


It's hard to imagine life without air conditioning, especially in the summer! If you're fortunate enough to live in an air-conditioned home, you may have wondered how this cooling machine works.

Air conditioners cool your home through evaporation, a process in which liquid turns into a gas! And when a liquid changes to a gas, it feels cool in the process. In the case of an air conditioner, the liquid evaporates in metal coils that are inside of your house. The coils are then nice and cool, and a fan blows air across them. You feel this cool air every time the air conditioner kicks on.

But how does the gas turn back into a liquid so that it can keep doing its cooling job? This process called condensation" occurs outside of your house in a part of the air conditioner called the compressor. Inside of the compressor, the gas is squeezed, gets hot, and condenses back into a liquid. The liquid must now cool down! The heat is blown away from the liquid with the help of a fan. You may have noticed this big fan in the air conditioning box in your backyard. Once the heat has escaped, the liquid can return to the house and evaporate all over again so you stay cool!

by Mya Kagan (Whyzz writer)


The substance inside of your air conditioner that turns from a liquid to a gas (and then back to a liquid) is called a refrigerant. In most cases, this refrigerant is Freon, which at one time was also used to cool refrigerators!

Further Information

Air conditioners use a lot of electricity. And electricity is mostly won from burning fossil fuels which lead to the greenhouse effect that is warming temperatures on Earth. Make sure you use your air conditioning responsibly and to shut it off if you leave the house!


How Air Conditioning Works. How Stuff Works.How Does an Air Conditioner Work? How Things Work. California Energy Commission.