The compressor is the engine of an air conditioning system and is the most essential part. It works with a refrigerant to form a closed circuit that moves heat from inside a building to the outside. The compressor is located in the outdoor unit for central and split systems, and is responsible for most of an air conditioner's energy consumption. It is also usually the most expensive component. The compressor pressurizes the refrigerant to increase its temperature, following the combined gas law which states that if pressure increases, temperature will follow suit.
This causes the refrigerant to heat up quickly when it is compressed. The unit heats the coolant to ensure that the temperature surpasses the outside temperature, allowing heat to flow naturally from the hottest to the coldest bodies. The coolant then passes through cooling tubes and copper coils, connecting the inside to the outside. It absorbs heat from inside and changes from gas to liquid before pushing the heat to the outside and allowing cooler air to enter. Once it has released its heat, it returns to a gaseous state and re-enters the interior.
An indoor fan then blows air into the cold coils, circulating cold air throughout. The condenser coil receives high-temperature, high-pressure refrigerant from the compressor. It works in opposition to the evaporator coil, which contains cold refrigerant while condenser coils contain hot refrigerant. The condenser coils are designed to allow heat transfer to the outside, with a condenser fan blowing air into them so that heat can be dispersed outside. Before returning to the evaporator coils, however, it must be cooled. This is where a thermostatic expansion valve comes in handy.
It removes heat from inside residential or commercial properties and removes it from outside. The copper tubes absorb depressurized refrigerant in its liquid form as it passes through this valve. When indoor air blows over cold coils, heat from inside is absorbed according to the second law of thermodynamics which states that heat flows naturally from hot to cold. Condenser coils require a condenser fan for this process while evaporator coils need an air controller fan to blow air over them. The refrigerant absorbs heat from indoor air before evaporating into vapor. Ventilation grilles located inside allow warm air into the house before it is absorbed by refrigerant and brought back to compressor for pressurization and heating.
Once it passes through condenser coils, a large and loud condenser fan pushes air through them so that heat can be transferred outside. Once heat has been released, refrigerant returns through expansion valve which depressurizes and cools it down before passing into evaporator coils. The cycle is then repeated with refrigerant performing same absorption process over and over again.
