VaporCompression

Vapor compression is a method of refrigeration and heat pumping that uses a mechanical compressor to raise the pressure and temperature of a refrigerant vapor. In the basic cycle, the refrigerant passes through four main components: a compressor, a condenser, an expansion device, and an evaporator. The compressor increases the refrigerant’s pressure and temperature, sending high-pressure vapor to the condenser where it releases heat to the surroundings and condenses into a high-pressure liquid. The expansion device lowers the liquid’s pressure and temperature, producing a cold, low-pressure mixture that enters the evaporator. In the evaporator, the refrigerant absorbs heat from the space or process to be cooled and boils back into vapor, completing the cycle.

Performance is described by the coefficient of performance (COP), and the efficiency depends on component choices and operating conditions. Common compressor types include reciprocating, scroll, rotary, and centrifugal designs. The system typically uses refrigerants that may be natural or synthetic; historically CFCs and HCFCs were phased out due to ozone depletion, and many systems now use HFCs or low-global-warming-potential alternatives such as CO2 (R-744), ammonia (R-717), or hydrocarbons (R-290, R-600a) with appropriate safety measures. Applications range from domestic refrigerators and air conditioners to heat pumps and industrial refrigeration. Advantages include relatively high efficiency and broad operating ranges; limitations include energy consumption, refrigerant leaks, and environmental or safety concerns with certain fluids. The technology continues to evolve toward lower-GWP refrigerants and more efficient components, including advanced control strategies and heat exchanger designs.