After 2020, only recovered, recycled, or reclaimed supplies of R-22 will be available. Drop ins are the alternative. 1/1/2025 R 454B will be one of the new refrigerants is flammable. Has some propane in it. The main reason companies don't want to fix a 22 system is the cost of refrigerate and labor. The newest 22 system is close to 25 years old. Company comes out charges 1 k week later breaks again who's mad you are. Still have a 25 year old furnace and a evap coil with a 25 year old metal condensate pan.