It is an enormously bad idea to use hydrocarbon-based refrigerants (Duracool included) in an automotive A/C system. These are blends of isopropane and isobutane. They're sold under names like EnviroSafe, RedTek, DuraCool, HC-12a, OZ-12, MX-12a, ES-12a, HC-12a, "anything"-12a. They're inexpensive and widely touted as "drop ins", even though legally there is
no such thing as a "drop in " replacement for R12.
Do these hydrocarbon blends work? Yeah, they work.
Is it safe to use them? The sellers say yes (of course), but can't seem to provide enough supporting data, despite 15 years of trying, to pass the refrigerant safety tests ALL refrigerants are required to pass before they're legally approved. The sellers claim it's due to politics and Big Refrigerant Inc's
desire to own the market. EPA says
Don't. MACS says
Don't. Pretty much every other knowledgeable authority on the subject
says Don't.
One argument commonly advanced for these refrigerants is "You carry 20 gallons of gasoline and you don't worry about that, so why worry about 2 pounds of hydrocarbons in your A/C system?" The answer is that the fuel system is specifically designed and tested to store, carry and transport flammable fluids. The A/C system isn't. What's more, our old Mopars don't have anywhere near the ventillation that newer cars with their through-flow air exchange systems have. In a newer car, a small leak of hydrocarbon refrigerants is not as likely to lead to a critical (BLAM!) accumulation of hydrocarbons in the passenger compartment. In an older car without through-flow (all A-bodies and most other '60s-'70s Mopars), the opportunity for accumulation is much greater.
And don't think you're not at risk 'cause you don't smoke in your car. There are lots of sparks happening all the time in and near the passenger compartment. Blower motor, all the dash switches, static electricity, etc. It only takes one.
Freon does not "burn". In fact, like other halons, it tends to extinguish whatever fire it encounters. Fire + Freon can produce a toxic gas (phosgene), however, injury or death from phosgene created by a fire in an A/C equipped vehicle is
far less likely than injury or death from fire or explosion caused or aggravated by hydrocarbon refrigerants. Think about it: The antidote to toxic gas exposure is ventillation. That's easy to accomplish and you've got time to do so after the exposure. The only antidote to a hydrocarbon explosion is not being there when it happens. That's much harder to do since it involves predicting the future.
if you mouse around on the websites selling this stuff, you'll find them talking about "legal 2nd-generation drop-in" refrigerant. This is a bit of doublespeak. Here's how it works: It's illegal to replace R12 with hydrocarbon refrigerants, but it's not illegal to replace R134a with hydrocarbon refrigerants. A law against the latter was never written, 'cause there's no reason why anybody
would ever replace R134a with hydrocarbons. Unfortunately, that legal omission is being treated as a loophole by those selling hydrocarbon refrigerants. The idea, they say, is to convert your system over to R134a (which is legal), then replace the R134a with hydrocarbons. Nudge nudge, wink wink, elbow in the ribs, and if you happen, wink wink, to forget the "change to R134a" step, wink wink, why, that would be awful. Wink wink. Just terrible. Wink wink.
Hydrocarbon refrigerants work but are a really, really, really bad idea in motor vehicles. It'd be a terrible shame to get killed, disfigured or maimed because you were too cheap to fix your A/C correctly. "Correctly" means using one of the two refrigerants designed and intended for the purpose: R12 or R134a. There are many substitute refrigerants on the market that are not so hideously flammable as the hydrocarbon blends, but they're still not a good idea. FRIGC, for example, is nothing more than R134a with a small amount of R600 added to try to shore-up R134a's poor oil return characteristics. Performance and materials-compatibility are poor. FRIGC is legal, but remember there is *no such thing* as a "drop in" for R12, legally speaking. EACH AND EVERY different refrigerant is legally required to use its own unique service fittings and a fully compliant retrofit is required, including approved labelling. Just dropping "Gunk-12" or "Freeze-a-lot" or any other non-R12 substance into an R12 system is a poor idea for a whole bunch of reasons. When your system breaks (and with most of these substitutes, it *will* break sooner than later), it's hard as heck to find a service shop local to wherever you happen to be that'll work on it. Virtually every reputable shop has a refrigerant identifier. If they sniff your system with the ID box and it says anything other than R12 or R134a, most shops will say "Sorry, shop elsewhere". (and if they detect hydrocarbons, they will usually tell you very quickly to get the hell out of their shop).
Because all refrigerants are required to be recycled, not just vented to the atmosphere as in the old days, a separate recycling jug/system is required for each refrigerant. Most shops have two and only two: R12 and R134a.
Replacing any components? New compressor, condenser, anything else? Most component warranties are void if you use anything but R12 or R134a, and yes they can tell.
The refrigerant, even if you're buying R12, is such a small part of the cost of getting and keeping a vehicle A/C system working. In the long run it does not pay to use something that's not supposed to be in the system.
