The Operational Principles of Industrial Air Conditioners

Compressor

• The compressor is the heart of the air conditioner unit and typically the most expensive part to replace. Its job is to drive the refrigerant through the system and is the loud sound you hear when the AC is running. The compressor pumps the refrigerant in a constant loop, moving it though the evaporator and condensing coils. There are five different types of compressors: Reciprocating, scroll, rotary, centrifugal, and screw.

Heat Exhange

• Air conditioners get cold air from the hot exterior air through heat exchange. It is done by compressing the refrigerant so that its temperature rises to 150 degrees Fahrenheit or greater. Then the unit pushes this gas through the outdoor condensing coil to lower its temperature by moving some of that energy to the outdoor air. As the gas leaves the outdoor heat exchanger it is pushed through an expansion device that naturally lowers its temperature as the gas's pressure is reduced. This cold gas is pushed though the evaporator coil that cools the inside air moving across the heat exchanger. Then the gas goes back to the compressor and the cycle repeats.

Heat Pumps

• A heat pump is similar to an air conditioner but its systems are reversed. Its job is to heat the inside air by extracting energy from the cold outside air. It is exactly the same as an AC unit, but its condensing and evaporator coils are reversed.

Fluids

• Air conditioners can also be used to exchange energy from fluid to fluid or fluid to air. This is accomplished by running the fluids past the coils instead of air. Special consideration needs to be taken if the fluid is particularly acidic or corrosive because it can quickly destroy the metal heat exchangers.