Danno

Any news on R134b? Also butane is a good refrigerant for AC systems.

jonnybgood

True that the ban on CFCs did not take place until the patent expired for Dupont. True that there was an increase in the ozone hole mainly over the south pole and that the past few winters it appears to be getting smaller.

ljd-924SE

where can i get some R12? my friend has worked at autozone for years and tells me the stuff is nearly impossible to find these days.

Greg86andahalf

What if the evaporator begins to leak? If your fuel tank leaks explosive vapors, at least those vapors are not plumbed into the dash area and blown into occcupant's FACE with a fan!

See above. Not only is it illegal, which may not matter to some, but you could kill your mechanic, youself or family members. Not to mention the liability if you are in a wreck or if the system decides to let go at a gas station and the liability if you sell your car to someone with explosive material in the A/C system.

I would'nt use a blend and certainly not propane. If R12 is not practical, do a proper R-134 retrofit, which is more detailed than simply dropping a couple of cans of R134 into the system. Do a forum search. I posted a manifesto on R134 conversion about a month ago. It pays in the lnog run to do A/C systems correctly.

Greg

heybiff

You are supposed to have a certification to buy R12 on Ebay ( or at all), but I managed to get 4 cans in the mail from two separate auctions with no questions asked or answers given.

heybiff

z3bra

True, like I said, use it at your own risk. It does have an odorant in it that's somewhat pine smelling but having had to discharge the system to fix a problem with my compressor, it's not very "piney" smelling and belive me if it's leaking you'd smell it.



Greg, while I completely agree that doing the work properly is important, I think a lot of people tend to demonize things because of theoretical events. Much like the exploding Ford Pinto gas tank myth. Of all the Pintos sold I recall reading that the actual number that experienced the problem was less than 20. (16 or so I believe but I can't confirm that as fact so don't take that as gospel).

I do the work on my A/C system. Not a mechanic. In the unlikely event that I did take my car into a mechanic I would also inform them that my refrigerant is what it is as a matter of courtesy even if they're not working on it just so that they know what it is. Since I do my own work, I know what's in there so it's no surprises.

Yes hypothetically a wreck could cause it to vent, no argument there, but we're talking a pretty small amount of Isobutane here too (12 oz or so depending on the car). I know it sounds bad using a hydrocarbon, but I think it's safe to say that cars even with isobutane as a refrigerant don't go up in giant fireballs ala the old TV show chips. I'm not suggesting that there isn't some additional hazard running it vs. R12, but it's not the Boogeyman in the closet that some people think it is either. Would I use it in my house? Probably not, since there's a lot more places that a leak could collect and the leak go unnoticed. In a car however, I feel that it's a calculated and acceptible risk. R134a can be an explosion hazard as well under the right circumstances so it's hardly risk free. Since it has been linked to seizures, who's to say an R134a leak in the evaporator couldn't cause you to have one and drive your car into oncoming traffic, pretty slim odds but it's still a risk. If isobutane leaks and blows through the vents, you just have a harmless hydrocarbon blowing in your face and smelling funny unless you happen to be smoking and it just happens to be the ideal amount to combust. I don't smoke so I don't care. I don't base my decision off of that unlikely of a what-if? scenario though, I'm just using what obviously works much better for blowing cold air out of the vents. If I light myself on fire in doing so well, you can be the first to say you told me so.

From a legal standpoint, yes it is technically illegal in some states to use a hydrocarbon based refrigerant but not illegal on a federal level. They've been using hydrocarbon refrigerants in Europe for a long time as well. Speeding is illegal too in every state including Montana but it still happens.

If I sell my car I'll probably put 134a back in to avoid any potential liability, and as far as a leak letting go at a gas station, sure it *could* happen, but the right ratio of air/fuel is a pretty narrow one to allow ignition and while it is possible it's a pretty unlikely thing to happen. Realistically if the system let go at a gas station you'd have some additional hydrocarbons in the air that would quickly dissipate and that's about it. I'd worry more about getting struck by lightning myself. Somebody hitting you head on or T-boning you and killing or seriously injuring you is a far more likely occurance than your Isobutane filled air conditioner exploding and hurting you. Also, keep in mind that the amount of refrigerant used is pretty minimal so what is there will burn off quickly even if it did ignite as a "flash fire." It's only explosive when contained otherwise it just does the "woof" thing like when you light your gas grill and it singes your eyebrows. It might not be an ideal refrigerant for smokers however.

Like I've said a bunch of times though yes there is definitely a potential for something to happen and if you're considering it, you should make an informed decision with those risks taken into consideration. I have done so and I don't think that running the Isobutane refrigerant vs R134a presents sufficient additional risk to outweigh the benefits such as still being able to use mineral oil in the system (or PAG or Ester oil as all of them are miscible in the isobutane). Isobutane gives much better cooling performance. It has relatively good availability. It results in a decreased load on your engine and compressor since the Isobutane is an easier gas to compress than R134a is by a huge margin. Isobutane doesn't become corrosive if there's any water in the system (unlike R12 and moreso R134a) so if your condensor's dessicant isn't working very good or has been humidified too much from your system being open for too long, using isobutane it doesn't matter. Even if you don't have a nice vacuum pump it's ok as fully evacuating the system prior to charging with isobutane isn't a must like it is with R12 and R134a. Lastly, if I want to, I can vent Envirocool to atmosphere all day long and it's perfectly legal and safe aside from it being flammable.

Additionally if R12 is exposed to flame it decomposes into phosgene gas which if you didn't know was used as a chemical weapon in the early part of the 20th century and does all sorts of nasty things to your lungs even if you don't breathe in enough to kill you. The main reason they started using it as a chemical agent was that it does not have any immediate choking effects so compared to chlorine that was in use as a chemical agent at the time you ended up breathing in a lot whereas chlorine is enough of an irritant that your body will do everything it can to not let you breathe it in. I'm not sure about R134a's combustion byproducts but they're probably equally bad for you. Isobutane on the other hand is water and C02 and maybe a little CO and other relatively harmful compounds in very very minute amounts assuming a less than perfect combustion process. Again pretty unlikely this is an issue but if we're going to compare the hazards it is only fair to bring this up.

So with all that said, if you're aware of the risks and doing your own work, then a Hydrocarbon refrigerant might be worth looking into. If you're going to have someone else work on the system it's probably not the best choice, the flammability and other theoretical catastrophe just waiting to happen arguments are certainly a very remote possibility but realistically it's such an unlikely combination of events that it's really not a big deal.

z3bra

Even if you don't have the certification it takes 20 dollars and about 2 hours of your time to take the test online and get certified. It's an open "book" test (yes legitimately, the only stipulation is that you're not supposed to let anyone else help you take it). It's a pretty easy test anyway so if you can't pass it with flying colors with it being open book, I don't know what to tell ya.

It's a lifetime cert anyway. It's basically a "convenience tax" as far as I'm concerned and is only there to keep the completely uninformed person from buying R12. As much as anything the test is just to ensure you're familiar with the procedures not to certify you as an expert in air conditioning systems.

Cyrus951

R12 is illegal in California. I called about a dozen shops till I found a place that sells R12. They charge $100 a pound. Our systems hold just over 2 lbs, are there any alternatives other than the conversion?

z3bra

Drive to AZ or NV and buy it there? It's still expensive but not as bad. The last can I bought was 35 for a 1lb can or you can buy the stuff on ebay provided you have the magical certification card. Worst case convert to R134a or something else. (not beating the dead horse in this post I promise). I don't think the term illegal is correct, it's just that there is a finite supply of R12 so the price has risen accordingly and a lot of places don't bother with it now. Then again you are in Kalifornia so it really may be illegal there and if so I guess I can't say it surprises me much.

What I'd really like to know is why is the only state that's figured out that so many common household chemicals etc are found to cause reproductive harm according to the notices on labels of coutless products. They're so more smart!