R12 versus R134

[Sunroof]

Okay, in my 73.5 T, I have the under dash AC vents, a front condenser with cooling fan and a rear deck condenser. My updated compressor still uses the old R12 stuff. In a long discussion with my mechanic we went over the pros and con of taking the old compressor and converting to 134 (flush, new drier, fittings). My mechanic felt that the cost of conversion would be close to the cost of recharging on R12 ($70/pound) X 3 which includes replacing an old suspect line.

He did mention that it may not cool as well but felt the two condensers coupled with the under dash vents would be fine.

I know their have been threads in the past about R12 and getting licenses to import, finding it cheap, or looking at the black market approach, but I do not want to find myself a year or two down the road crossing some border with cans of R12 attached to my undercarriage!! I figure if converting will make it cheaper to recharge in the furture why not do it now, since its fairly cost effective.

thoughts?, experiences?

Regards
Bob
73.5 T

[stlrj]

I plan on using a refrigerant blend called Hot Shot instead of R12 as soon as I fix all the leaks in my hose fittings. It seems the best choice since it is compatible with R12, can be used to top off an R12 system, has a higher BTU value than R12 so it will cool better, pressures are equivalent to R12 and you use less of it to fully charge your system.

Am currently taking the refrigeration class through my Stationary Engineers Union. When I asked our instructor about Hot Shot, his final comment was, "you'll like it."

Cheers,

Joe

[Thomas Owen]

Bob - the A/C never worked very well on any 911 I had until I got my '88 and it is r12. My understanding is that because of the amount of hose in the a/c system in a 911 the r134 will disappear quicker because it is a smaller molecule. I would stick with the r12 if you have a source for it, specially if your hoses are not new.
Regards,

[JackT]

My car does not cool as well as it did with the old compressor. Mechanic says because of now using 134 instead of R12. I am thinking about converting to R12. My car olnly cools when it is cool outside, pretty much useless. The rotary compressor does not put the drain on the motor that the York compressor did.

[Sunroof]

Thanks Guys.
It gets hot in got old Atlanta and I could use all the cooling I can. Its just I constantly hear $60-70 a pound for R12 and soon it should be gone from the planet! The compressor conversion to R134 is just fittings and purging, aside from a new drier. I still have many yards of old red AC hose on this old jewel and I am not in a positon to rip everything out and start with fresh stuff.

I am banking on dual condensers and the knee high level vents to take the edge off.

Regards
Bob

Bob,
I've gone through the same internal battle as you are on the 134 conversion. I even went online and got the certification to buy freon. You can still get r-12 for $30 +/- per lb. Everything I see says it will still be around for quite a while, so I'm not going to the expense of a 134 conversion.

This weekend, I hope to install a new rotary compressor (Sanden clone, Zims $200) and a new Procooler high efficiency receiver/dryer ($299), and have the system flushed, evacuated and charged with r-12. Since I got the certification, I'm going to buy and store a case of r-12 and top off every year.

I should have the results next week and will post on the board.
Mark

[jlex]

Why not just get the certification to buy the R12? It's pretty easy & painless. Go to www.imaca.org for information on downloading the study material & taking the on-line test. (International Mobile Air Conditioning Association).The certification costs only $15. http://www.imaca.org/

I did the study & took & passed the test in about 2 hours. It's an open book test & isn't hard. Just read the info carefully, have the index in front of you & take the test while everything's fresh in your mind. Just as soon as you pass the exam, you can download a temporary certificate that allows you to buy over the counter. The actual certificate is send a couple weeks later.
After you're certified, go to ebay & get R12 for about $20 per can (or cheaper). I also bought some at the discount auto store up the street for about $22. Call around, I'm sure there's lots available in your local parts stores. Get going.
regards,
jlex.

[BlueSkyJaunte]

Read this before you decide on "drop in" replacements for R-12:

http://www.heco.net/TheTruth.htm

(Verification of the information at the above link is left as an exercise for the reader)

[Harold_89_911]

I will start with the disclaimers that I'm not an AC expert etc. but I wanted to give you my experience. I have an old Saab 900 with a functional AC system. The R-12 got low on it after a couple of years. Since I live in Ventura, I rarely need the AC but it's just nice to have some days when I have to drive to LA. I didn't want to go through the expense of a R-12 refill on this car but found this suggestion on the Saab Net.

http://www.btt.org/ES.html

I used it about two years ago and it still works very well. But again, I don't live in Texas. Once you use this stuff and mix it with the R-12, you cannot go to a regular AC shop anymore because it would contaminate their R-12 recycling process. Also, the hose they provide is kind of cheesy and didn't fit the compressor connection very well (leakage). Lastly, make sure you do not connect it to the high pressure fitting because you will take the risk of exploding the can.

In summary, it's working for me, is better for the environment (just a hydrocarbon gas and not chlorinated), but there is some controversy about the ignitability and the wisdom of using it with an internal combustion engine.

[Steve W]

As another alternative take a look at this faq:

Freon Altenatives

I am currently using basic torch propane mixed with a little isobutane as a substitute for R12 in a vehicle of mine, and it works very well. In fact it is more efficient than r12 and gets good bit more colder. Not to mention the fact that propane is a heck of a lot less expensive, about $2 for a 14 oz torch tank. Isobutane, as used in camping fuels is optional, but mixed in at 20% lowers the overall required gas pressure a bit to emulate R12 more. Since they are both hydrocarbons, they are completely compatible with all the lubricants, seals, hoses, and properties of a R12 system. In fact back in the old days, before freon was invented, propane was the standard gas used in all refigeration systems. But I must reiterate what Harold has stated, in that you cannot bring it to a regular AC shop for service unless you purge out all the propane/isobutane from your system first.

I know, some of you may be thinking, ohmygawdmycarwillblowupandiwillfry, but before any one decides to flame me read the above faq first. It was determined that that risk is more like 1 in 1 million. We are comparing 18 oz of propane to the 100 lbs. of gasoline in our cars.

[jlex]

There's a section in the IMACA test materials that deals with cross-contamination of refrigerant materials. Generally, a shop should have a recover-only machine dedicated to contaminated refrigerant. After recovery, it should be stored in a DOT certified gray and yellow recovery cylinder. I'd just call the shop beforehand & make sure they can recover contaminated material with a dedicated machine. Seems logical that all shops would have a separate machine.
I still recommend taking the certification test to buy R-12. Download the 22 pages, study them, take test & be done with it. I've noticed cans of r-12 on Ebay now selling for less than $20. Go for it... it'll be a hot summer.
regards,
jlex.

[speeder]

Jlex, Does one need any expensive equipment to purge/fill A/C system on cars? That would be the deciding factor for me DIY.

[930slant]

The secret to the r134 is to find a shop that knows what they are doing. I converted two years ago from r12 to r134 and never got really cold air at the vents until i recently changed mechanics. I now get 40 degrees at the vents and am VERY happy. The 134 still leaks through the hoses and at some point I may consider changing to the barrier hoses. However, one of the reasons to change is that the recharge of r134 is much cheaper than r12 thus off setting the need to change hoses. I suppose I'll decide about the hose change based on how long I keep my 88 930.

[R22tech]

Good God....you guys are scaring me! Sorry in advance if this sounds condensending. First of all, don't even discuss "drop-in replacements", there isn't any currently accepted in the a/c industry-don't even try and tell me, "the mechanic said this stuff works great!" He either didn't say it, or he is an idiot when it comes to a/c repair. People who believe this nonsense are the same who believe taking some vitamin will make your boobs look like Pamela's. It just ain't gonna happen!
R134a is an accepted alternative to R12. It works well in a system DESIGNED FOR R134a, not very well in an R12 designed system. The only reason mechanics recommend this conversion is to make money the "easy" way: no rules, no E.P.A. forms to fill out, no documentation, the ability to be "environmentally friendly" for folks who care, ect. Don't go the R134a route if you don't have to.
As far as getting certified, apparently you can get it online. What this means is that you are aware and have been tested on the proper usage, recovery and disposal of certain types of refrigerants. You understand the E.P.A.'s guidelines about refrigerants and their requirements. You, theoretically, may purchase refrigerants if you are certified, but some find out that wholesale distributers won't sell it to you unless you are employed by a licensed HVACR company.
A fellow Pelican bought cans of so called "R12" off ebay and brought them over to me so I could install it it for him. The cans looked "fishy" to me, but they were labled R12 so I attempted to install it with his guage manifold. Being that they were in weird cans with the wrong fittings, some escaped as I was charging the system. This stuff didn't smell anything like R12! In fact, it smelled like spray paint from a can. It didn't take long to discover his a/c system was contaminated and the pressure were all wrong. We immediately evacuated his system- he still has no a/c after almost a year. Moral: don't buy off ebay and don't believe everything you read!
So how is R12 sold? The little 12 & 16 oz. cans have been outlawed for years now, so if you come across one beware. Unfortunately, the smallest size R12 currently on the market is a 30 pound tank. It costs about $1000.00 +/-, which is another reason why repair shops aren't so quick to recommend it.

Bob- forget about all the b.s. high efficiency driers and crap out there designed to steal your money. Put in the R12 and a new, correct drier, and be a cool dude. Oh, and tell your wife I said hi!

I think I was just spanked.

[bonedaddy]

I can't help but point out that this whole fiasco was wrought by politicians legislating based on a hypothesis that has as much "proof" as those vitamins that are supposed to make your boobs look like Pamela's. Ozone depletion my *ss!

Bone,
It goes deeper than that. From what I read, Dupont's patent was about to run out on r-12 and they held a valid patent on r-134. Makes you wonder if there was any undue influence on the legislation. Not that I'm complaining. That's capitalism at work.

[Sunroof]

Okay.....
Seems like their are numerous options from propane cocktails to granny's secret coolant syrup! I just want to be cool fellas and if you never came through Atlanta in the summer time, you would pay the piper on R12 from your local mechanic to stay cool.

I do not believe I will convert at this point from what I am learning about 134. I still have several old red clothe hoses that will suck 134 up in heartbeat that I am not prepared to replace at this time.

I will explore the R12 license option since I will probably have to recharge every year and it would pay in the long run, but their is truth in what I read about selling in bulk and eliminating the availability of those nifty cans.

Always appreciate the education on this site.

Stay cool

Bob
73.5 T

[schulr]

Lets continue this through one more question, I have an 87 Targa and in Atlanta. Its going to get hot and the unit blows only recycled air. The AC was converted to 134 so I bought a recharge kit to do the job myself. In reading what everyone is saying, it sounds like I should go back to R 12? Comments on this?

If not, the kit came with a can of oil along with the 3 cans 134. Is the oil required? How many cans of 134 is required. There was no presure gague provided. Seems the instructions says the oil is only used when you totally evacuate the system in a conversion.

I am like Bob, just want to be cool when the time comes. Can't always just take the top off.

Bob

[Joeaksa]

Very good discussion group on the net for air conditioning issues.

Joe

http://www.aircondition.com/wwwboard/alternative/