With the phase-out of R-22 and the increase of R-22 retrofit solutions, there has been some confusion in the market about replacements versus "drop-ins" regarding R-22 retrofits. The information below will try to dispel some of these myths. Arkema recommends using Forane® 427A (R427A) - The EASY RETROFIT™ for your r-22 retrofit solution.
When it comes to drop-ins, the truth is that there are none.
The hope of “drop-in” refrigerants has become common over the years. The term "drop-in" dates back to the phase-out of chlorofluorocarbons (CFCs). During the transition away from CFCs, "interim" refrigerant blends containing hydrochlorofluorocarbons (HCFCs), such as R22, were developed to be used in existing R12 and R502 equipment. These refrigerants had a high degree of miscibility with the mineral oil used in existing CFC equipment. Retrofitting the equipment with these interim blends could be done with fewer concerns with oil management, making the retrofits relatively easy, leading to their description as “drop-ins.”
The term “drop-in” has now migrated to the present-day R22 phase-out. Presently, there are over 20 HFC-based R22 retrofit refrigerants. However, HFCs are not miscible with mineral oil, and instead typically require the use of a synthetic lubricant, such as PAG, POE (polyol ester), or PVE (polyvinyl ether) lubricants. Furthermore, the R22 retrofits are all blended refrigerants, which will not behave the same in all cases as a single component refrigerant like R22.
Some refrigerant suppliers have taken to describing these HC-containing HFC blends as “drop-in” retrofits for R22, even where they still recommend that the oil be changed to POE. Arkema Inc. does not advocate the use of the term "drop-in" as we believe the term implies a technician can just “drop” the refrigerant into an R22 system without doing any other work. Or even worse, interpreting "drop-in" as to mean being able to top off an existing R-22 charge with a retrofit refrigerant.
Proper guidelines should always be followed when retrofitting.