A little off topic AC conversion R12 to R134A.

[Chris142]

Before trying Red-Tex find and study the info on it. It's primarily propane, does indeed work well as a car refrigerant, but has the disadvantage that it's a gas at normal pressures/temperatures and highly explosive when mixed with air. So in using it in an automotive refrigeration system you're piping an explosive gas into a metal/glass box in which you'll be sitting. Any leak, say in a minor crash ...

The following link has a pretty good discussion and there's a YouTube video a few posts down with a demo of propane in a car:

https://gmtnation.com/forums/threads/has-anyone-here-used-red-tek-12a-freon-refrigerant.18857/

There's a reason it's not used commercially for car A/C.

It's also illegal to use in a car.

 

[JHZR2]

It's also illegal to use in a car.

I think that depends per state. Federally it’s a matter of being a sham retrofit or not.

Not advocating for its broad use, but it has utility for folks without pro tools, to help find leaks.

 

[atikovi]

Do they still make AutoFrost? I still have a half full 30 pound drum. Supposed to be a drop in replacement if I recall.

 

[LDM]

I've used EnviroSafe in multiple vehicles, including an old 92 S10 Blazer that I "converted" to R134a first. And by converted I mean I replaced the R12 fittings with R134a, flushed the system, replaced a damaged line, replaced the accumulator, and then put new oil and EnviroSafe in it. Works better than R134a. I know people say "its illegal" but unless someone plans on coming onto my private property to start checking out what I'm doing, they are going to have a hard time proving anything in the end. The new R1234yf is also flammable so the whole argument that other flammable refrigerants can't be used is rather pointless anymore.

 

[ofelas]

The new R1234yf is also flammable so the whole argument that other flammable refrigerants can't be used is rather pointless anymore.

Bingo. We won't even get into DuPont's timely patent expirations or gasoline lines here.

Not to mention, AC refrigerant oils are also rather flammable.

I'd be far more worried about the proximity of spark + propane on a gas grill, especially considering most folks don't understand the difference between lefty-loosy vs righty-tighty.

On domestic systems actually designed for R134a, that appropriate refrigerant works rather well.

On an old R12 system, the R12a fills are a no brainer, especially on non domestic vehicles with challenged condenser/evaporator sizes.

It's kinda important to use soapy water/UV dye to leak test though, rather than the old torch method ;-)

 

[kschachn]

I've used EnviroSafe in multiple vehicles, including an old 92 S10 Blazer that I "converted" to R134a first. And by converted I mean I replaced the R12 fittings with R134a, flushed the system, replaced a damaged line, replaced the accumulator, and then put new oil and EnviroSafe in it. Works better than R134a. I know people say "its illegal" but unless someone plans on coming onto my private property to start checking out what I'm doing, they are going to have a hard time proving anything in the end. The new R1234yf is also flammable so the whole argument that other flammable refrigerants can't be used is rather pointless anymore.

Sort of, the flammability of R1234yf is not like propane or butane and neither is the energy released during combustion.

Ahh the problems when thermodynamics is at odds with politics.