As a result of the R-22 phase-out, numerous new refrigerant fluids have been created to aid in the transition from HCFCs to HFCs.

In this phase, the dominant refrigerants are 410A and 407C, both of which are presently accessible. R-134a (for chillers, huge roofs, and so on) and R-404A/R-507 (for refrigeration) will also replace R-22 in some applications.

R-407C is a zero-ozone-depletion combination of R-32, R-125, and R-134a HFC refrigerants. It was created to mimic the qualities of R-22 and will be employed in a variety of air conditioning and refrigeration applications, either in new equipment or retrofitting existing R-22 installations.

R-407C must be used with polyolester (POE) oil since it is insoluble in mineral oil or alkylbenzene.

When retrofitting an outdated R-22 system, the mineral oil or alkylbenzene lubricant in the system must be flushed out and replaced with POE. New R-407C-specific equipment will be pre-charged with the OEM-recommended POE lubricant and will be ready for usage with R-407C.

Charging

Although R-407C has features similar to R-22, it is not acceptable for use in all R-22 systems.

R-407C would not be appropriate in a flooded evaporator system, for example. This is because the components of R-407C have a tendency to separate (fractionate), which can significantly affect system performance. When determining if retrofitting is appropriate for the system you are working on, please reference the equipment manufacturer’s requirements. R-407C should be charged as a liquid at all times. Because it is zeotropic, it will fractionate if charged as a vapor, resulting in poor system performance – and, potentially, system failure. Furthermore, if the refrigerant supply in the cylinder is released as a vapor, it may become out of specification.

Install a valve in the charging line to flash the liquid to vapor when charging in instances where vapor is routinely given to the system, such as adding a refrigerant charge to a running system.

Remember that POE oil is very hygroscopic and can rapidly get polluted if moisture enters the system. To maintain the system dry, you must take the necessary precautions.

WESTRON® is a refrigerant supplier, and it offers an inclusive range of commercial, substitute, transitional, and long-term refrigerants. You can contact them for any maintenance or refrigerant gas change.