Natural refrigerants are naturally occurring substances that can be used as cooling agents (heat transfer medium) in refrigerators and air conditioners. They don't harm the ozone layer and have no or negligible climate impact, but may pose operational safety risks if not properly managed.
- Ammonia (R-717), used in industrial refrigeration plants for more than 130 years, is deemed to be environment-friendly, economical, and energy-efficient
- The natural refrigerant carbon dioxide CO2 (R-744) has a similarly long tradition in refrigeration technology
- Non-halogenated hydrocarbons (HC) such as propane and iso-butane
CFCs - These are substances containing carbon, fluorine and chlorine chemicals (CFC). CFC refrigerants, such as the once popular R-12, have the highest ozone depleting potential (rating 1) and are a greenhouse gas (GHG). They are now banned from production within all countries covered by the Montreal Protocol.
HCFCs - These are substances containing hydrogen, carbon, fluorine and chlorine (HCFC) chemicals. The HCFC refrigerant R-22 was the most widely used refrigerant for light commercial air conditioning, refrigerators and freezers until concerns over ozone depletion were raised. The HCFCs have a rating of ozone -depletion potential (rating 0.05) lower than CFCs (rating 1) and are therefore classified as “transitional substitutes” during the time it takes to commercialize new ozone-safe alternatives and replacements.
HFCs - These are substances containing hydrogen, fluorine and carbon chemicals. The HFC gases are used extensively in every day refrigeration and air conditioning systems (RAC systems). HFCs have no ozone depletion potential, but these chemically based synthetic refrigerants are powerful greenhouse gases that contribute to global warming if released into the atmosphere. Depending on the exact type of HFC, they can be a 20,000 times more powerful greenhouse gas than carbon dioxide.