R-422D is a low and medium temperature retrofit blend for R-22 refrigeration and air conditioning systems. With properties very similar to R-22, components such as TXVs do not need to be changed. In most cases there will also be no need for an oil change, making R-422D the most economical retrofit solution for R-22 refrigeration systems.
Because R-422D has a lower discharge temperature, most low temp R-22 systems will no longer engage the liquid injection module. This will result in significant savings in energy use and a boost in capacity compared to running with R-22.
The hydrocarbon component in R-422D 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.