Servicing Existing Units
Existing units using R-22 can continue to be serviced with R-22. There is no EPA requirement to change or convert R-22 units for use with a non-ozone-depleting substitute refrigerant. Such changes, called “retrofits,” are allowed if the alternative has been found acceptable for that type of use. R-407C is allowed for retrofits but R-410A is not allowed in retrofits due to its higher working pressures. In addition, the new substitute refrigerants would not work well without making some changes to system components. As a result, service technicians who repair leaks to the system will most often continue to charge R-22 into the system as part of that repair.