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HFC
- R422A
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. |