How An Air Conditioner Works

This is by no means a detailed explanation of how an air conditioner works. It is intended to be a brief description so that you can better understand some of the other information you will find on this site. Basically all air conditioners you will come in contact with work the same way. This includes central, window, ductless, portable, and packaged air conditioning units.

There are basically four main components common to all air conditioning systems. An air conditioner can't function without any of these.

1. Compressor - The compressor circulates refrigerant throughout the air conditioning system. The easiest way to explain what the compressor does is to compare it to a pump although it is much more complicated than that. It draws low-pressure refrigerant vapour in through the suction port and discharges high-pressure refrigerant vapour out the discharge port.
2. Condenser Coil - (Outdoor section) the high-pressure refrigerant vapour flows from the compressor to the condenser. The condenser has a fan, which circulates air through it. As the air, which is cooler, than the refrigerant in the condenser, passes through the condenser fins it absorbs heat from the refrigerant. This removes heat from the refrigerant and it begins to condense. By the time the refrigerant leaves the condenser it has become a liquid.
3. Metering Device - There are different types of metering devices such as thermostatic expansion valves, cap tubes and orifices. These devices regulate the flow of refrigerant throughout the air conditioner. As the liquid refrigerant from the condenser passes through the metering device it enters the evaporator coil. The metering device is usually located at the evaporator coil inlet.
4. Evaporator Coil - (Indoor section) the evaporator coil is the component that absorbs heat from the space being cooled. As refrigerant enters the evaporator coil it begins to evaporate. A fan blows air through the evaporator coil and some of the heat in the air is absorbed by the refrigerant passing through the coil. This causes the refrigerant to boil and once again turn to vapour. This results in cooled air leaving the air conditioner and entering the space being cooled. The refrigerant leaves the evaporator coil and returns to the suction port of the compressor and the cycle begins again.

Each of the components listed above are connected with copper pipe that the refrigerant flows through. These are the common components of all air conditioners and the principal of operation is the same for all of them. Hopefully this has given you a better understanding of how an air conditioner works.