The A/C delemma.........

Doing the upgrade will broaden your market when it comes time to sell.

Not too many years ago adding Vintage Air to hot rods was pretty uncommon. Now it's almost a necessity (think steamy southern/summers with the windows up during afternoon rain showers).

 

No one pays a higher fee for a 308 because the air has been converted but I am sure there are many that will pay less if the air doesn't work.

Don't worry about that part of all this.

 

I value the cool air far more than an award my car would not get, even if I still had an R12 system. Most buyers will too. Non-working AC can certainly be a negative when selling, original equipment or not.

 

R12a is a cheap, no hassle alternative.

 

It's also illegal to use.

 

No. Just not in the approved list for new vehicles. That’s way the sale is not banned for sale and easily available.

 

"It's also illegal to use."


It is also illegal to exceed the speed limit or remove a catalytic converter...

But, it IS a DIY thing. No shop is likely to agree to install it, even in US states where it is not illegal. FWIW, last time I researched this a few years back when I installed Duracool (same stuff) 17 US states prohibited the use of "flammable refrigerants." 33 did not.

FWIW, I think it will eventually be certified for vehicle use; it is commonly used throughout the world for other types of ac systems. It is more efficient and has less environmental impact the the "regular" refrigerants. The folks that lobby against it for automotive use seem to be the folks who produce conventional automotive refrigerants.

That being said, if you do decide to use it, you should at least be aware of the fact that it may be illegal in your state/area and make your decision about it armed with all the necessary information. It DOES work much better as a refrigerant than R134 in these cars and is actually slightly more effective than R12 was though that difference is very slight - more on the theory/mathematics level than a practical difference.

 

It is illegal to use as a retrofit. It can be used in systems specifically designed for inflammable gases.

I am not saying "don't use it," I am only saying, be informed if you do use it. Even if you believe I am incorrect and decide to use it, the system so converted must be properly labeled and have retrofit charging ports installed. If you bring your car to a professional to have it service after installing R12a, you must ensure the shop knows of the retrofit as it cannot be mixed in their recovery machine, and you will likely be liable for the disposal of the entire machine's contents if it is contaminated with R12a.

 

To the OP, if you retrofit to 134a, I would recommend replacing the condenser with a multi-pass unit and installing the largest cfm fan you can possibly fit to cool it.

 

And change every hose

 

Yep, 134 has smaller molecules than R12 and so, leaks much easier. It's another plus for the hydrocarbons which have even larger molecules than R12 and are even less leak-prone. I've had Duracool in my 328 for several years now with the original factory hoses from 1989 - the charge of Duracool has not diminished at all over that time.

 

Please cite the state or federal law or regulation. Thanks

 

"Under SNAP, all flammable refrigerants, except HFC-152a and HFO-1234yf, are listed as unacceptable for use in new and retrofit MVAC systems. This includes all hydrocarbon refrigerants. When a refrigerant is listed as unacceptable, its use is illegal."

https://www.epa.gov/mvac/refrigerant-transition-environmental-impacts

 

It’s not a retrofit and not illegal. I’m also not sure about it’s flamability. It’s regularly sold. If it was illegal it could not be sold

 

Do the retrofit. No further embellishment needed.

 

It's a mixture of propane and isobutane, and last I checked, they're fairly inflammable. Also, R12a is actually HC-12a, the HC meaning "hydrocarbon." And since "...all flammable refrigerants are listed as unacceptable for use in new and retrofit MVAC systems. This includes all hydrocarbon refrigerants. When a refrigerant is listed as unacceptable, its use is illegal."

 

Note that flammable refrigerants ARE legal in most US states. SNAP refers to manufacturing of vehicles, not end user changes. Also, NOTE that the reason the hydrocarbon refrigerants are not acceptable is because sufficient testing has not yet been done to certify them. It hasn't been adequately tested for motor vehicle use BECAUSE the manufacturers of motor vehicle refrigerants don't want it to be certified. It's like ethanol in gas...we have it because of the political influence of the industry, NOT because it's better.

 

Yes, it's flammable.

 

So, they're retrofitting refrigerants on new car assembly lines now... silly engineers, you'd think they'd design the cars for the correct stuff. :/

 

No, cars are made to fit within a regulatory environment. That means compromise. The best engineering solutions are rarely used, because they butt up against a regulation - that's why aftermarket tuning houses exist. If you want power, they can give it to you, at the expense of fuel economy and emissions - a manufacturer can't do this. Well VW tried a work around, and look where that got them. The AC was designed around R12, not R134a. Propane mix works far better - the fact that it isn't approved is a regulatory problem, not an engineering one. And commercial HC mixes have powerful odour additives, so your nose will spot a leak way before it becomes an issue.

 

Of course... I was being a smart aleck as Mike996 had said that SNAP regulations were only for new cars, despite the fact that the EPA link I posted clearly states hydrocarbon refrigerants are "Unacceptable Substitute Refrigerants". And as I posted earlier, I didn't necessarily say not to use the stuff, only that one should be very careful in using it, clearly labeling, etc., it's use so a repair shop doesn't contaminate their equipment.

 

My point is that the SNAP stuff applies to manufacturers NOT to what you do with your car. It is not illegal to use Duracool (for example) in your car's AC system if you live in MOST US states. BUT it is illegal for Chrysler (for example) to put Duracool in a production car.

 

The EPA site clearly states that R12a is illegal as a retrofit refrigerant in motor vehicle air conditioning. And while it may squeak past the law for you to use it, it renders the A/C system unrepairable by a professional shop. Again, I'm not saying don't do it. Just be mindful of the consequences, including issues related to selling said vehicle down the line.

 

We don't agree on the legal details but I totally agree with your comment on being AWARE of the laws and, as I said earlier, that shops will not use it; it is, at least for now, totally a DIY thing. The issue for us with these cars is simply trying to achieve decent cooling without having to re-engineer the AC system. R12 will do the job but is difficult now to obtain. R134 won't do the job unless the entire system is changed to accommodate the fact that it is around 1/3 less efficient that R12. The hydrocarbon refrigerants equal R12 in their ability to cool and are, therefore a viable means to cool an otherwise OEM 3x8. IMO, the issues that sometime come up re flammability are unrealistic in actual operation. 20 gallons of gasoline being pressurized and delivered through a system that involves a multitude of connectors/pipes/hoses is safer?