HFC, HFO and HCFC refrigerants
Also known as: synthetic refrigerants, fluorinated gases, CFC, fluorinated refrigerants
Short definitionThe generations of fluorinated refrigerants. CFCs and HCFCs contain chlorine, thin the ozone layer and have been phased out; HFCs are chlorine-free but have a high GWP; HFOs are the latest generation, with a very low GWP.
The abbreviation gives the contents of the molecule: an HCFC has hydrogen, chlorine, fluorine and carbon, an HFC has no chlorine, and in an HFO the carbons are double-bonded. R12 is a CFC, R22 an HCFC. R134a, R32, R404A and R410A belong to the HFC family. R1234yf and R1234ze are HFOs. Each generation came to fix the fault of the one before: the Montreal Protocol closed the ozone problem, and the F-gas rules and the Kigali Amendment are closing the high-GWP problem.
When choosing a gas, the family decides two things: oil and flammability. Chlorinated gases run with mineral oil, HFOs and HFCs need POE; every retrofit that changes family changes the oil as well. Most HFOs are A2L. The common gases in the field are an in-between solution: HFO/HFC blends such as R449A, R448A and R513A stay A1, while R454C, with a GWP of 148, is A2L. As GWP goes down, flammability goes up. The family cannot be told from the R number; look at the label.