Refrigerant-22 Alternatives

 

Geothermal heat pumps currently on the market use HCFC-22 or R-22 as the refrigerant. This is the same refrigerant used in many residential and commercial air conditioners and heat pumps, except for large centrifugal chillers, which in the past used CFC refrigerants.

HCFC-22 has a very low ozone depletion potential (0.055) compared to 1.0 for CFC-11 and CFC-12, the two other most popular refrigerants used in large chillers. Most scientists consider HCFC-22 to be a bridge refrigerant that can take us through the phase-out of -11 and -12. No health or safety issues have been identified with R-22.

The 1990 Clean Air Act Amendments call for HCFC-22 production, not use, to be phased out by the year 2030. This could be extended at a later date if continuing atmospheric tests so indicate.

Long term substitutes for HCFC-22 are being developed and will probably be blends of various HFC refrigerants (such as R-410A), since they have little or no ozone depletion potential. None are expected to be a "drop-in replacement".

Regardless, R-22 will be available over the useful life of any geothermal heat pumps installed now. There is no current "drop-in" substitute for R-22. Research and development continues to seek substitutes since R-22 is the predominant refrigerant used in screw, scroll, and reciprocating air conditioners.