What are natural refrigerants?
Natural refrigerants are substances that exist naturally in the environment. Having very low or zero global warming potential (GWP) and being free from PFAS (“forever chemicals”) they are considered the definitive solution to the environmental damage caused by synthetic refrigerants.
Refrigeration systems with natural refrigerants are predestined to meet the growing global demand for cooling.
The most widespread natural refrigerants used in HVAC/R applications today are hydrocarbons such as propane (R-290), isobutane (R-600a) and propylene (R-1270), carbon dioxide (CO2, R-744) and ammonia (NH3, R-717). Other natural refrigerants are water (H2O, R-718) and air (R-729), used only for special applications, or sulphur dioxide (SO2) and methyl chloride (CH3Cl), which are no longer used.
Our choice: R290 propane
Fully compliant NATURAL REFRIGERANT
GWP = 3, OPD = 0, PFAS free
Propane is naturally occurring in good supply, has excellent thermodynamic properties as a refrigerant, a stable price and can be used in a wide variety of appliances.
It has a long history in refrigeration and, being an organic compound (hydrocarbon), it has no Ozone Depletion Potential (ODP) and a negligible direct global warming effect. Pressure levels and refrigerating capacity are similar to R22, and its temperature behaviour is as favourable as with R134a.
There are no particular problems with materials. In contrast to NH3 (Ammonia), copper materials are suitable as well, so that propane can be used in semi-hermetic and hermetic compressors.
An alternative option: R32
GWP >150 but PFAS free
Despite not being a natural refrigerant, R32 is PFAS free and is commonly used in smaller air conditioning systems today.
R32 comes out on top as the best performing and most efficient alternative to R410A.
Having GWP = 657 could be phased out by the F-GAS update but remains a good alternative in cases where natural gases cannot be used for safety reasons* (i.e. flammability) or battery energy storage applications**.
Another option: R744 Carbon dioxide
Fully compliant NATURAL REFRIGERANT
GWP = 1 and PFAS free
Carbon dioxide (CO2) is also a good environmentally friendly option we are investigating.
Carbon dioxide offers high heat exchange and low pumping power when used as a secondary fluid.
* Amendment 16 – proposal for a regulation Rcital 13 Where alternatives are not available or cannot be used for technical or safety reasons, or where the use of such alternatives would entail disproportionate costs, it should be possible for the Commission to authorise an exemption to allow the placing on the market of such products and equipment for a period of maximum 4 years.
** Amendment 21 – proposal for a regulation Rcital 13 f Some cooling equipment used in conjunction with batteries needed for the Union's energy transition could contain fluorinated gases. However, this sector was not analysed in the Impact Assessment accompanying this Regulation. In its report on the implementation of this Regulation, due by 1 January 2027, the Commission should assess the impact of this Regulation on the Union's battery market.
