Best Practices For When to Retrofit An Existing System

When To Retrofit Your System

Anytime a compressor is replaced.
Today's replacement compressors have POE oil in them, so conversion to an HFC alternate refrigerant, such as R-407A, is much easier.
The best performing R-22 alternatives (R-407A or R-407C) require POE oil, and most R-22 systems have either mineral oil or alkylbenzene oil in the compressor. Therefore, an oil change is required.
If an oil change is difficult or not possible, then HFC/hydrocarbon blended refrigerants, such as R-422B, are available for use in air conditioning applications, which will allow the continued used of mineral or alykylbenzene oil. However, there will be a loss in capacity and efficiency when compared to R-407C or R-407A.
When choosing a retrofit refrigerant, it is recommended to consult the EPA's listing of approved refrigerants by application, found at www.epa.gov/snap/refrigeration-and-air-conditioning.

EPA Deadlines for Retrofitting to Various Refrigerants in Retail Food Refrigeration Systems

The federal SNAP restrictions regarding HFC's no longer apply; however, state regulations may still exist. Please refer to the Refrigerant Regulatory Updates Page for state specific information.

Good, Better, Best Refrigerant Choices: Air Conditioning

R-422B

This is a good choice for customers who want to switch to a non-ozone-depleting refrigerant, but do not want to change oil.

R-407C

This is a better choice than other refrigerants for customers who want to change to a non-ozone-depleting refrigerant, or who are replacing the compressor.

R-22

This is the best choice for a well-maintained unit which will continue to function for many years.

AC Cooling Capacity Relative to R-22

Guidelines To Consider Before Starting a Retrofit

Follow these guidelines to maximize system capacity and efficiency:

Seals and O-Rings Change elastromeric seals such as Schraeder cores and o-rings
TXVs Regardless of whether the TXV is replaced, the superheat should be checked and reset for greater efficiency
Fixed Orifice Metering Devices May need to be replaced with a larger size due to an increase in mass flow of alternative refrigerant
Distributor Nozzles Alternative refrigerants may yield higher pressure drops. Existing R-22 nozzles should be checked for capacity prior to retrofit
Capillary Tubes The length of the capillary tube must be adjusted to match the refrigerant blend
Filter Driers Filter driers and/or cores must always be replaced during retrofit
Temperature Glide Alternative may experience temperature glide so it is wise to refer to dew point and bubble point for proper charging/system adjustment
Pressure Controls Adjust to compensate for pressure differences between refrigerant blends
Lubricant Issues HFC blends require POE lubricant. Follow manufacturer guidelines for levels and procedures

Your Next Steps

If Retrofitting your system isn't an option, explore your other opportunities:

Maintain Replace

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