Vapor-Compression Refrigeration

Vapor-compression refrigeration is one of the many refrigeration cycles available and is the most widely used method of air conditioning for buildings and automobiles. It works by circulating a refrigerant through four main components in sequence: a compressor draws in low pressure refrigerant vapor and compresses it to higher pressure and temperature, a condenser then removes heat from the compressed vapor so it condenses into a liquid, an expansion valve drops the pressure abruptly so part of the liquid evaporates and cools, and an evaporator absorbs heat from the space being cooled as the refrigerant fully vaporizes again before returning to the compressor. The cycle is used across domestic refrigerators, commercial food storage, building and vehicle air conditioning, industrial process cooling, transport refrigeration, electronic cooling, and oil refineries and petrochemical plants. It is considered a mature, comparatively inexpensive technology with good energy efficiency, which is why it remains the dominant refrigeration method worldwide in both residential and industrial use.