R-422A is a low temperature retrofit blend with properties very similar to R-404A. It can directly replace R-502, R-402A/B, R-408A, R-404A and R-507. R-22 low-temp systems can also be retrofitted to R-422A with some component changes (TXVs, for example).
With increased regulatory pressure on leakage and recordkeeping of ozone-depleting refrigerants, R-422A offers an HFC-based retrofit solution for R-502 and the HCFC-based low temperature blends. The hydrocarbon component in R-422A helps promote oil return in systems containing mineral oil or alkylbenzene. Although HFC refrigerants won’t mix with these oils, the hydrocarbon addition thins the oil and keeps it moving around the loop More complicated piping arrangements or large hold-up volumes may still require some oil be changed to POE.
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