• The most commonly known use of refrigerants is the refrigerator.contents of fridge image by Christopher Hall from Fotolia.com
  
  Refrigerants are chemical combinations that remove heat rather than make things cold. During a refrigerant cycle, heat is taken from one place and moved to another, or transferred. Depending on the size of the area needing cooling--such as a personal refrigerator compared with a large chiller-- different refrigerants are required to handle the job. Commonly known refrigerants include carbon dioxide and ammonia.
  
  

Physical Aspects

• A gas such as ammonia can act as a refrigerant. When ammonia or another refrigerant is compressed, it heats up. Once compressed, ammonia changes form from a gas to a liquid. The liquid ammonia boils and becomes a vapor. Once a vapor, the temperature of the ammonia drops dramatically. The negative temperature of the ammonia cools the entire refrigerator. The ammonia is sucked up by the compressor, and the cycle is repeated.
  
  

Purposes

• Refrigerants are used to cool refrigerators, coolers and food-storing or transportation devices. They can also be used to cool vehicles and in air-conditioning systems that control the temperature of an entire facility.
  
  

Types

• Refrigerants can be used alone or in combination. Ammonia itself is a refrigerant, but refrigerants such as hydrochlorofluorocarbons were once used for the same purposes. Hydrochlorofluorocarbons are a combination of hydrogen, chlorine, fluorine and carbon. These man-made compounds have a toxic influence on the natural environment.
  
  

Risks

• The phasing out of ozone-depleting refrigerants began in 1987, according to the United States Environmental Protection Agency (EPA). Refrigerants by the name of hydrochlorofluorocarbons, as well as some others, contain chlorine, which contributes to the destruction of the ozone layer. These chemicals are also greenhouse gases, contributing to the rise of global warming.