Well…would you look at that! Give it a try and report back what kind of refrigerant you use. Once you’ve found the refrigerant, here is what all those numbers actually mean: R-22 is the oldest refrigerant and has been phased out. R-410A is the current refrigerant and is being phased out, R-454B is the newest refrigerant. All these transitions are in an effort to lower global warming potential! | Trane