To understand how air conditioners work you must first understand that they all operate on the same natural principal: evaporation is an endothermic reaction. That is, the act of evaporation absorbs the heat from the space around it. This is why sweating cools you off and how air conditioners work. It pulls away your body heat as it vaporizes and your skin dries.

A basic air conditioner unit consists of a compressor, a condenser, an evaporating unit and two fans. Consider for a moment that an air conditioner is essentially a refrigerator for your house! It contains the same fundamental parts, but instead of cooling an insulated compartment, the heat-absorbing evaporator and heat-releasing condenser parts are exposed to the ambient air inside and outside your house, respectively.

Structurally speaking, and evaporator and a condenser are identical and typically consist of a winding brass tube with a great deal of fins attached to it. The fins provide more surface area with the air which assists in the heat-exchanging cycle. Through the these tubes runs a refrigerant such as Freon mixed with a little oil which lubricates the compressor.

1. The heat-exchanging cycle begins when the cool refrigerant vapor arrives at the compressor (1), which packs together the vapor particles converting it to a high-pressure, high-temperature vapor before it enters the condenser.
2. As mentioned before, the metal fins help the condenser (2) release the stored heat of the vapor thereby converting it to a pressurized liquid.
3. This liquid then travels through the narrow opening of an expansion valve (3) into the evaporator where the pressure dissipates quickly, causing the liquid to turn back into a gas.
4. This vaporization absorbs the heat from the surrounding air, and is assisted by the metal fins which are also present on the evaporator (4).
5. The now cool vapor then arrives back at the compressor - the cycle is complete and that's how air conditioners work!

Two fans further help the heat-exchange process with the ambient air on both sides of the cycle by blowing over the fins on both the condenser and the evaporator. An air conditioner technically only transfers unwanted heat to another area; it does not eliminate it. In cooler months, some systems can even function as heat pumps by operating in reverse!

This, of course, covers just the basics of air conditioning. Modern air conditioners apply the above principles to a broad spectrum of different types of air conditioners to match whatever suits your situation and come in a spectrum of sizes. Whether you're looking to cool a single room or an entire house. They are loaded with many helpful Features to Look For and are held up to certain Energy Star efficiency standards so you can beat the heat and still not sweat the electric bill. Stay frosty, friends!