Components of an Air-Cooled System

Evaporator Coil

The coil containing the cold freon liquid over which the warm air from the interior of the home is passed. The heat from the air is absorbed by the freon liquid in the coil cooling the air but causes the freon to boil and turn into a gas. The coil gets its name because the freon in the coil evaporates or turns into a gas when it absorbs the heat from the air passing over the coil. The location and use of the coil may indicate the type of air conditioning system. An evaporator coil that is incorporated into a warm air furnace is called a split system. An evaporator coil that is used to warm air is called a heat pump. An evaporator coil that is not part of a heating system is an independent system.

Compressor

Compresses the freon gas to increase its temperature. The compressor is needed to make the temperature of the gas much higher than the temperature of the air outside the home. The compressor is the main device that moves the freon through the system and is usually located next to the condensing coil.

Condensing Coil

The coil containing the high pressure and high temperature freon over which air on the exterior of the home is passed. The air on the exterior of the home absorbs the heat from the freon in the coil. As the high pressure freon gas loses heat, it turns back into a liquid. The coil gets its name from the freon condensing or turning back into a liquid. Condensing coils are generally cooled by air, however, some systems use water to absorb the heat from the coil.

Freon Expansion Device

A device designed to reduce the pressure of the freon liquid coming from the condensing coil. Reducing the pressure greatly reduces the temperature of the freon. (Opposite action of the compressor.) The device reduces the pressure of the freon by regulating the amount leaving the device. The device is usually located before the evaporator coil.

Blower

Fan used to move the warm air from the interior of the home, over the evaporator coil to be cooled, then back into the home.

Condensate Tray and Line

Captures the moisture that develops on the evaporator coil as the air in the home is cooled. The line directs the water to a plumbing drain.