Refrigeration is maintaining a space cooler than the surrounding. It is removing heat from an enclosed space or from a substance and rejecting it elsewhere, for the primary purpose of lowering the temperature of the enclosed space or substance and then maintaining that lower temperature. The methods of refrigeration are ice, mechanical, absorption, steam jet, and air cycle.
Refrigeration equipment include refrigerators, ice machines, walk-in coolers and freezers, reach-in coolers and freezers, cooling tower chillers, gaulin homogenizers, meat, fish and deli merchandisers, refrigerated deli display cases, bakery cases, hot food display cases, bouquet coolers, floral display refrigerators, convenience store coolers, walk-in display, supermarket and restaurant equipment,etc.
Refrigeration is used in private homes and public buildings, breweries, chemical, manufacturing and petrochemical plants, convenience stores, supermarkets and restaurants, flower shops, meat packing houses, refrigerated railroad cars with ice tanks for dairy products, refrigerated trucks conveying perishable goods and temperature-sensitive chemicals, trains, airplanes and sea-going vessels. It is also used in processes like alkylation of butenes and butane and tempering of steel and cutlery.