This is a take off of my earlier post regarding upgrading an AC system to R-134a.
There is another option that I just became aware of, though they've been out there for years: hydrocarbon blends. RedTek, Enviro-Safe, Duracool, OZ Technologies, etc. all make a similar product that is a blend of propane, butane, and other hydrocarbons.
Obviously, there is a flammability issue that the manufacturers reduce by including retardents into the blends. The rub is that leaks could affect the blend -- retardants could leak off leaving only the flammable HCs behind. Let's table this issue. Please!
There is a major question of legality in the US. Can't vent any refrigerants. Also can't upgrade R-12 to anything but R-134a. In the US, the upgrade path must be R-12 -> R-134a -> HC blend. There are all kinds of other legal and ethical issues. We can debate the politics of refrigerants, ozone depletion, and global warning. But, let's not. There are 5 million discussions on these topics, the legalities of refrigeration servicing, etc.
What I want to know is compatability. If I put the HC blend into an empty R-12 factory air conditioning unit from 1967, will I damage my original components?
Thanks.