only thing i dissagree on is flammable risk of a propane based refridgerant, consumer labs in colarado tried to blow it up without success. As did myth busters, i have used propane and it works better than r-12, but i would never recommend using it simply because if, they yell at me if they went up in a blaze of glory.

 

just remember one thing about blended. if one springs a small leak one or more of the blends molecules will be "liter or smaller" than the others and will separate and leak out first. topping it off will not bring back the same cooling capacity. one should empty system and start over to keep it up to snuff.