How Air Conditioners Work
Portable, Central and Room Air Conditioning
Air conditioners work basically the same way as a refrigerator except that the area it is designed to cool is much larger than your average icebox. It utilizes the unique cooling capabilities of a refrigerant chemical to remove heat from the air.
- we explain three basic concepts
In understanding how an air conditioner works, there are three basic concepts on refrigeration that could help. Firstly, heat always moves from warm to cold. Secondly, the boiling point of a refrigerant will change depending on its pressure. This means that the higher the pressure the higher the boiling point and the lower the pressure the lower the boiling point. And lastly, refrigerant will boil and absorb heat from its surrounding environment when the environment is warmer than the refrigerant. If the surrounding environment is cooler than the refrigerant while it is boiling then it will condense, become a liquid, and lose heat.
Air conditioners work in a cycle which usually begins when the refrigerant is compressed in the compressor causing it to heat up and become a hot, high pressure gas. The heated gas is then moved through a series of coils in the condenser in order to disperse the heat which converts the refrigerant into a liquid.
The liquid refrigerant then goes through to the evaporator coils where it evaporates into a cold vapor. Warm air from inside the building is circulated over these coils and the heat from the air is absorbed by the refrigerant vapor. The newly cooled air is then circulated throughout the building or room and the refrigerant returns to the compressor to begin the cycle again. The evaporator and condenser are also sometimes referred to as heat exchangers.
It is well known that hot air rises, so vents are placed in the ceiling to suck the warm room air into the air conditioner to be taken through to the evaporator coils. This is where it will be cooled by the refrigerant gas then sent back into the room by the fan through vents that are usually placed at floor level.
A thermostat constantly monitors the temperature of the room or building. Once the required temperature has been reached it will turn the air conditioner off. When the temperature begins to rise again, the thermostat will turn the air conditioner back on. Most air conditioners, such as central air conditioners and many room air conditioners, have this option.
Room air conditioners work in the same way as a central system but are far more compact with the entire cycle taking place in a single unit placed in the room. Split system air conditioners also work in the same way, but are divided into two units. The air handling unit inside the building contains the evaporator coil and the unit containing the condenser and compressor is placed outside. They are connected via refrigeration pipes and utilize ductwork or tubing to circulate air throughout the system and the chosen area.