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 the 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.