The job of your air conditioner is move heat from inside your building to the outside, thereby cooling you and your building. Air conditioners blow cool air into your building by pulling the heat out of that air. The air is cooled by blowing it over a set of cold pipes called an evaporator coil. This works just like the cooling that happens when water evaporates from your skin. The evaporator coil is filled with a special liquid called a refrigerant, which changes from a liquid to a gas as it absorbs heat from the air. The refrigerant is pumped outside the facility to another coil where it gives up its heat and changes back into a liquid. This outside coil is called the condenser because the refrigerant is condensing from a gas back to a fluid just like moisture on a cold window. A pump, called a compressor, is used to move the refrigerant between the two coils and to change the pressure of the refrigerant so that all the refrigerant evaporates or condenses in the appropriate coils.
The energy to do all of this is used by the motor that runs the compressor. The entire system will normally give about three times the cooling energy that the compressor uses. This odd fact happens because the changing of refrigerant from a liquid to a gas and back again lets the system move much more energy than the compressor uses.
MAINTAIN THE SYSTEM
Routine maintenance such as changing filters can be handled by most consumers, but others require professional service.
It’s a good idea to brush dirt and obstructions from the coils and the drains at the start of each cooling season. Depending on the system and the consumer, this may require a service call from a professional.
If the system is not producing as much cold air as is normal, it could also be an indication of a refrigerant charge or airflow problems. These problems may require servicing.
Source: www.ashrae.org; 2014.