Synthetic refrigerants such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) have a negative impact on the Earth’s atmosphere as they destroy the protective ozone layer. Their ozone-friendly successors however, the also synthetic hydrofluorocarbons (HFCs), contribute to global warming up to 4,000 times more than CO₂. Even though they are specified as greenhouse gases (GHG) under the Kyoto Protocol, they are still widely used in refrigeration appliances. The concentration of GHGs in the atmosphere is at an all-time high and the amount of HFCs is growing.
A sustainable alternative to synthetic refrigerants is already on the market. Natural refrigerants are made of substances that occur naturally in the environment. "The natural five" include hydrocarbons (HCs), carbon dioxide, ammonia, water and air. The direct emissions of natural refrigerants have no, or only a negligible, impact on the climate, should they escape into the atmosphere.
The refrigeration, air-conditioning and heat pump (RACHP) sector will face many changes over the coming years. Due to their harmful impact on the environment, many of the refrigerants currently used will be banned or strongly reduced in number over the next decades as agreed under the Montreal Protocol and the Kigali Amendment, and as outlined in the EU Regulation on fluorinated greenhouse gases (F-Gas Regulation). The legislative pressure on the sector will continue to increase. Switching to more sustainable options is therefore becoming more urgent for manufacturers and users of RACHP systems. There is a growing trend towards introducing natural refrigerants as an environmentally friendly alternative that is less expensive compared to other synthetic refrigerants with a low global warming potential. They are also considered “future-proof” as it is unlikely that any new environmental legislation will prohibit or severely limit their use.