How Your Air Conditioner Turns Hot Air Into Cold Air

Your refrigerator and your a/c work in a similar fashion. The only difference is that instead of only being responsible for cooling a small, closed environment your ac has the difficult task of cooling a whole house, or building.

How exactly does your A/C work? This is a good question to ask because if your air conditioner ever breaks down it will definitely help if you are familiar with its design so you can able able to diagnose the problem and fix it.

Your air conditioner system using chemicals that are designed to turn gas into a liquid and then back into a gas again. Pretty ingenious, isn't it? The purpose of this action is to transfer the hot air that is inside your house to the outside.

As stated earlier your air conditioning system can be split into two main parts, though some people like to say there are three parts. You have the condenser (in which the compressor is in but some people label this a part by itself) and the evaporator. The condenser and the compressor are located on the left or right side of the house inside a square box. The evaporator is located right by your furnace on the inside of the house.

The refrigerant arrives to the compressor in the form of a cold, lower type pressure gas. The device then squeezes the fluid making it really dense making it really dense and hot.

The fluid leaves the compressor as a high pressure gas that is really hot and it goes into the condenser. What happens next? The fan on the condenser act like the radiator of a air and make the heat inside the gas dissipate rather quickly.

When the working fluid then leaves the condenser its a lot cooler and by then has morphed from a gas into a liquid that is under a tremendous amount of pressure. Where does it go next? It takes a trip to the evaporator through a very small hole. Once it gets here the pressure again drops and it becomes a gas.

While the liquid is changing back into a gas it also extracts heat from all the warmer air around it. Its interesting because, in fact, the heat that is found in the air is absolutely needed to separate the molecules from the substance from a liquid to a gas form.

Fans are also found on the evaporator and its used to help substitute the thermal energy with the surrounding environment.

The evaporator also has metal fins to help in exchanging the thermal energy with the surrounding air. When its leaves the evap the fluid is a cold, lower pressure gas.


Cold air is then circulated throughout the house or building via a fan. The hot air in an area weighs less than the cold air so it rises to the top of the rooms where it is sucked out via the vents where it goes back to the evaporator to be cooled again. Heat is taken from it and its blown back into the air ducts to be re-used. The vents for the cold air will usually be found floor level.

The whole process starts over and over again until the temepature in the house is where you set your thermostat. Once the thermostat senses that the temperature of the house is where you want it the whole a/c unit is turned off until it starts to get hot again.