The purpose of compression refrigeration in air conditioners is to remove heat from an enclosed space and lower its temperature. Compression refrigeration is a process that involves compressing and expanding a refrigerant gas to transfer heat from one location to another.
In an air conditioner, compression refrigeration works as follows:
Compression: A compressor in the air conditioning system compresses the refrigerant gas, raising its pressure and temperature. This compression increases the energy and temperature of the refrigerant.
Condensation: The high-pressure, high-temperature refrigerant gas flows into a condenser, which is usually located outside the building. In the condenser, the hot refrigerant gas releases heat to the outside environment, causing it to cool down and condense into a high-pressure liquid.
Expansion: The high-pressure liquid refrigerant then passes through an expansion valve or an orifice tube, which reduces its pressure and causes it to expand rapidly. As the refrigerant expands, it becomes a low-pressure, low-temperature mixture of liquid and vapor.
Evaporation: The low-pressure refrigerant then enters the evaporator coil located inside the building, often in the form of finned tubing. As warm air from the space passes over the evaporator coil, the low-pressure refrigerant absorbs heat from the air, causing it to evaporate and turn into a low-temperature vapor.
Compressed again: The low-temperature vapor is drawn back into the compressor, where the process begins again. The compressor increases the pressure of the vapor, and the cycle repeats, continuously removing heat from the indoor air and expelling it outside.
By continually cycling the refrigerant through compression and expansion, air conditioners can extract heat from indoor spaces, cooling the air and maintaining a comfortable temperature. The process relies on the properties of the refrigerant, which is capable of changing states between gas and liquid at low temperatures, making it an efficient medium for heat transfer.