Hydrofluro-Olefins (HFO) are considered the 4th generation of fluorinated refrigerant gases (GF). With a zero ozone depletion potential (ODP) and a low global warming potential (GWP), they are the fluorinated gas solutions with the lowest environmental impact.
HFOs are compounds formed from hydrogen, fluoride and carbon atoms.
HFOs, such as R-1234yf and R-1234ze, are pure solutions used in vehicle air conditioning systems and in chillers respectively, at medium and high temperatures. As they are only mildly flammable (A2L), their charge is limited. Due to their flammability and the range of temperatures, these pure substances are blended with other HFCs in order to produce non-flammable solutions (A1), to enable their use with low temperatures and also to reduce the GWP of HFCs.
A variety of non-flammable (A1) HFO+HFC blends have been developed for new systems and for retrofitting existing systems, such as:
- To replace R-134a (HFC): solutions such as R-450A and R-513A.
- To replace R-404A (HFC): solutions such as R-448A, R-449A, R-452A and RS-51.
- To replace R-410A (HFC): solutions such as RS-53.
