R12 Refrigerant not available - alternatives? - Page 2 - PeachParts Mercedes-Benz Forum

#16 01-07-2004, 09:15 AM

at least with HC gasses IF you have a fire it does not make phosgene gas

Also gotta remember that ANY gas mixed with oil and released under pressure has the potential to flash burn. The fact is when using HC gas is there is only 1/2 as much as freon or 134A so the possible fire would be smaller and not burn as long. Fuel is not the only fire source either. You also have several ounces of brake fluid, almost 2 gallons of oil, and several ounces of power steering fluid under the hood in addition to the diesel in the fuel filter and IP.

leathermang · #17 01-07-2004, 10:33 AM

Rebootit,
Your paragraph has all the markings of a person who has decided to do something and then goes back and is trying to justify it...
Most people hopefully see right through your spurious argument.
The items you choose to use as examples are Necessary to the operation of the vehicle... and are not anywhere near legitamate comparisons to a hydrocarbon GAS under pressure up in FRONT of the radiator with no attempt to shield from even light crash damage...
Hydrocarbon refrigerants are an UNNECESSARY AND EASILY AVOIDABLE RISK.

JimSmith · #18 01-07-2004, 10:56 AM

Guys,

I think Rick pointed out this subject has already been chewed enough. The referenced thread is an indication of the potential energy this subject has for generating explosive results just in this discussion forum. Lets not approach the event horizon of this black hole all over again.

I do not mean to stifle discussion, but I would like to avoid unnecessary trips down a path that leads to bad feelings between members of this forum. Unfortunately this discussion seems to be heading down the same path we went in the thread Rick identified. So, unless there is something someone has to add that is new, or a technical question that is new and has not already been covered in the past thread, lets try to refrain from keeping this thread alive with legal arguments (remember the guys passing laws also forced us to use MTBE in gas powered cars to address an environmental "problem") or opinions of how each of us would rather die in an accident. Thanks, Jim

leathermang · #19 01-07-2004, 12:49 PM

He started it !

He said those things AFTER Rick posted the reference.... and while I agree with what you ( Jim ) have said, some things deserve to have the replies in the same thread ... because some will only see that and not go read the reference....

#20 01-07-2004, 01:52 PM

I hit "submit" at about the same time the reference from Rick was posted. I had said before that the topic was well covered with both opinions (and we all know what we ALL have as well as opinions)

So I don't think I started anything. I'm not going to change Gregs view on HC's, and he is not going to change mine. I only offer personal experience using HC's, not the "party line" of those who pound the drum telling me how dangerous it is to use them.
Something to think about is how many posts for propane injection to increase performance you see on a diesel board. Don't these people realize how explosive this stuff is? It should be BANNED!Someone notify the EPA quick!

leathermang · #21 01-07-2004, 02:42 PM

We can put all the

we want..
But for your last post the critical question is :

Have you ever seen any of those propane lines routed IN FRONT of the radiator ?

#22 01-07-2004, 03:08 PM

No, I believe they are routed much CLOSER to the cabin where nothing is ever broken or leaks in an accident.
The perceived danger of using HC in A/C units on cars is not the fact that you have propane gas out front anyway. The risk that caused it to be banned in some states came from the belief that a leak inside the cabin with an open flame (smoker) could cause an explosion. I don't smoke in my car and the gas is scented anyway so you know if it leaks.
I respect your opinion that HC is dangerous and you should never use them. Some people felt the same way about the steam engine vs the horse, and then again when the internal combustion engine took the place of steam.

gsxr · #23 01-07-2004, 03:25 PM

I'm almost afraid to reply, but here goes:

1- PLEASE read the thread Rick linked to. It will save us all a lot of time re-hashing the same old thing. I'll put a few of the main points below:

2- Whoever told you R-12 is not available is either lying or mis-informed. Yes you can buy R-12 for $10-$30/lb.

3- R-12 will out-perform almost any other "replacement" refrigerant, except AutoFrost, and perhaps one or two others.

4- R-134a isn't "bad" stuff, it's just not efficient. The BAD stuff is the nasty oil you must use with it - PAG or POE. Please, please, please do not convert your stock R-12 (mineral oil) system to anything that cannot use mineral oil!! Once you've polluted the system, converting back to mineral oil is expensive & time consuming (requires disassembly & flushing of everything - not fun.)

5- Duracool and many other alternatives drop off in efficiency drastically at very high ambient temps. That means while it may work fine for someone in Montana, who swears it freezes them out of the car, the same stuff in Phoenix or Sacramento may be useless most summer days. Also remember what may be freezing cold for one person may leave another person sweating. It's all subjective & relative. So take any "replacement" refrigerant performance anecdotes with a large grain of salt!

6- I personally feel the "danger" with propane based refrigerants is exaggerated but that's a personal decision, IMO, if they are legal in your state.

My recommendation is to keep the system filled with a mineral-oil compatible refrigerant at any and all costs. Never convert to PAG/POE and try to avoid buying a car that's been converted, if possible. If you're too cheap to use R-12, many of the replacement refrigerants (for mineral oil) will work reasonably well up to at least 100F ambients (varies with humidity). If you find your chosen brand is not cold enough, verify proper fill quantity, and if correct you'll probably need to evacuate & re-fill with either R-12 or R-406b (AutoFrost), which will arguably give you the coldest outlet duct temps of almost any product on the market on VERY HOT days (100-120F ambients).

HTH,

Rick Miley · #24 01-07-2004, 03:32 PM

Dave, Tony (original poster) is in Perth, Australia. R12 might really be illegal there. Tony, do you know for sure?

gsxr · #25 01-07-2004, 03:54 PM

Ooooops! Sorry - my bad. I often assume posters are at least in North America, generally the USA. So yes, R-12 may truly not be available Down Under... I don't know. I'll try to watch that in the future!

#26 01-07-2004, 04:40 PM

Dave,
Is autofrost really all you say it is on vent temps in hot climate? Will it work with any oil? The reason I used duracool to start with was both my 123 cars had been switched to 134A so they had the nasty oil. Going d-cool this was not an issue and the performance was excellent in all temps here in central FL on the highway. In city driving staring with a hot car on a hot day the cooling is marginal but was poor using 134a. The selling point on 12a was I bought a 77 240d with the york style system and it had 134a which sounded like it was beating the compressor to death and cooled poorly. I switched to 12a and the system was 100% better. System was blowing a good 12-15 degrees lower vent temps at idle. I saw this and got to thinking my 300d may cool better with the 12a and gave it a shot. Results sold me. r12 (freon) may have been the best choice as far as vent temps but it would have required getting rid of all the PAG oil. Not practical as far as I was concerned. If AutoFrost would be even better I would switch again.

gsxr · #27 01-07-2004, 05:32 PM

AutoFrost seems to be pretty neat stuff. Drawbacks are:

1- It's a blend. You can't top it off - evacuate & recharge if it's low.
2- The lower duct temp means higher condenser temps, your engine cooling system can't be marginal.
3- It works ONLY with mineral oil! Not PAG/POE. So, you can't fill a 134a system unless you flush & convert the oil first.

Sooooo.... you, like many other people, are stuck with PAG/POE options only because your systems have already been converted from mineral oil. Sadly, the best refrigerants for low duct temps (especially at high ambients) all require mineral oil.

rhino · #28 01-07-2004, 05:41 PM

thanks for this thread. Living in the california desert, with high ambient temps, and a converted to 134 system, I have been trying to decide what to do to.

I'm thinking of finding a good shop in Tijuana to switch back to mineral oil and R-12...

leathermang · #29 01-07-2004, 05:47 PM

Everyone that is less than satisfied with their cooling system needs to keep in mind that the PRIMARY controlling factor in any system is the AIR across the Condensor. Put the biggest/best fan you can afford up front and be sure your Condensor fins are clean and straight.

TonyFromWestOz · #30 01-08-2004, 08:49 AM

Thank all who contributed to the research and discussion on this thread.
In Australia they banned automotive supply of R12 a few years ago and the EPA are trying to get everyone using the NEW gas (I don't rcall the code No.). R12 is no longer permitted for re-gas, and all R12 systems should be de-gassed and the gas returned (for HiTemp Incineration, I expect).
I was told by the MB mechanic who has serviced my MB 300D since new, that I should NOT have it converted to that gas, as it would not be able to cope with our HOT summers (40'C and higher on several days in a row and >35'C for 20-30 days during summer).
He recommended me to the A/C mechanic who regassed it with HR12. It worked well on the 38'C day we had on the 23rd Dec and om every other occasion since.

I do not have a problem using petroleum based refrigerant, despite a slightly increased risk of fire in an accident, rememvber there is only 300 grammes of this liquid gas in the A/C system. That is much less than the amount of petrol which could be pumped by a Spark ignition engine in the first minute after an accident. The reduced fire risk of using diesel fuel is only slightly offset by this gas.

I hope everyone has enjoyed this thread.
I have learnt much.
Tony