Refrigerant gas is a chemical product used in refrigerators, freezers, air conditioners and heating, ventilating and air conditioning units (HVAC). These gases, which have very low evaporation points, are condensed under pressure to chill the air. Through a process of repeatedly evaporating and condensing the gasses, heat is pulled out of the air and the temperature inside the room or unit is reduced. Different types of refrigerant gases include chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), hydrofluorocarbon (HFC), perfluorocarbon (PFC), and blends made from ammonia and carbon dioxide.
The first refrigerators built from the 1800’s until the 1920’s primarily used toxic gases such as ammonia (NH3), methyl chloride (CH3Cl), and sulfur dioxide (SO2). Unfortunately, the units occasionally leaked and caused several deaths, which prompted the refrigeration industry to put forth a concerted effort to find a safer refrigerant gas. The result was the discovery of chlorofluorocarbon (CFC) gas, which was a mixture of chlorine, fluorine and carbons. Freon® became the trademark name for a CFC gas that was primarily used as a refrigerant. This gas was colorless, odorless, nonflammable and non-toxic, and soon became the predominant gas used as a refrigerant.
In the 1970’s, scientists discovered that when CFCs leaked into the atmosphere, a chemical change occurred as a result of exposure to the ultraviolet rays of the Sun, resulting in a greenhouse effect and depletion of the ozone. Since that time, Freon® has been banned in many countries throughout North America and the European Union. In the United States, the Environmental Protection Agency (EPA) and the Clean Air Act established strict guidelines for the installation, repair, recovery and recycling of refrigerant gas. The European Union (EU) has also enacted strict controls through the EU F-gas regulations.
Some applications have replaced CFCs with HCFCs, which are a mixture of hydrogen, chlorine, fluorine and carbon. These have a shorter life when exposed to the atmosphere, resulting in less potential damage to the ozone. Another popular refrigerant gas is HFC, which contains no chlorine and is thought to have absolutely no negative effect on the ozone. PFCs are man-made chemicals composed of only fluorine and carbon ions, and are also considered ozone-safe. These replacement gases still cause environmental concerns if they leak into the atmosphere because they are considered greenhouse gases and may contribute to climate change.
Many industrial applications have moved back to naturally occurring refrigerant gas such as blends of ammonia and carbon dioxide, and research continues to search for more environmentally friendly ways to meet refrigeration needs. Refrigeration units must also be built to specific standards and commercial applications are subject to strict monitoring. Many countries, such as Canada, the UK, members of the EU, Australia, New Zealand, Japan and the United States require technicians who work on any units containing refrigerant gas to be licensed and certified.
Refrigeration has had a significant positive impact on life and society in the areas of nutrition, medicine, and physical comfort. The toxic gases of the early days have been replaced by refrigerant gas which works effectively and poses no health danger. Environmental concerns do exist regarding the use of these compounds, yet many believe that strict standards for equipment and maintenance have mitigated any negative environmental impact.