Mixing R12 With 134a, Yes We Can

[roedel]

Hello,

i am driving a 1990 LS400, in China, i love this car.

I bought it one year ago, last year the AC delivered ice cold air at max summer temperatures and humidity.

It gets hot and 100% humit here, crazy....

So this year i had to replace the compressor discharge hose and refilled the system with R12.

So far so good, the only thing i noticed was that the aircon did not blow as cold as before.

Low side and high side pressures were all within specs, strange.

Then i remembered that the previous owner told me his shop topped off the system with 134a..... back then i thought what the hack is he talking about.

Out of frustration i started to do some research and ohoooooo, found this Article:

Posted by George Goble on June 19, 1999 at 21:14:44:

In Reply to: Re: Replacement of R12 with R406a posted by John Strauss on June 16, 1999 at 16:07:09:

As you stated, the EPA has now made it "illegal" to mix

different refrigerants in cars.. Last time I looked, it was

still legal to mix 'em in stationary equipment.

R-406A in various mixtures with R-12 were run in a fleet of Humvees

early on (ambulance bodies).. R-406A by itself gives a 6-8F colder

duct temps than R-12, so with 50/50 R-12/R-406A the performance

gain was about 3-4F or 1/2 of using pure R-406A. (before EPA mixing

ban).

The "shocker" in illegal mixing is that mixing Freeze12, FR-12,

or just R-134a with R-12 (computer simulation on what happens)

start out with one slowly leaking R-12 system, gets down to about

50% remaining charge when the owner decides a recharge is needed.

1) Assume owner just "tops off" with R-134a (system has mineral

oil that R-134a will not "carry", but 50% R-12 remains, so oil

return to the compressor works fine. R-134a and R-12 form an

"azeotrope" with a boiling point of around -31F (R12 is -21.7F,

(R-134a is -14.7F, Freeze12 is around -8F) at 1 ATM. This

results in a performance improvment (capacity increase 25% or so)

along with slightly higher head pressures.. Performance gain

(over R-12) is about 2/3 of the gain of using 100% R-406A.

Freeze12 (80% 134a/20% 142b) is similar, except 2-3F warmer

than the above.. still much better than total R-12. This

"good performaning" mixture is called "contamination" by those

with vested interests in preventing it.

2) Next summer, system low again, user tops it off with R-134a,

now there is 25% R-12 (still enough to carry oil fine) and

cooling is still better than R-134a.

3) 3rd summer.. system low again.. tops off again with R-134a,

12.5% R-12 remaining.. still returns mineral oil fine.. cooling

now is about R-12 performance..

4) 4th summer...system low again.. tops off again with R-134a..

about 6% R-12 left, marginal mineral return, but probably

will work.. R-134a cooling performance..

5) 5th summmer.. top off again.. 3% R-12 left.. oil fails to return

compressor siezes up and fails.. IF using Freeze12 instead,

performance will be about +15F warmer than R-406A (autofrost)

Look how well this "illegal contaminated system" worked.

Now if legal...

1) remove all R-12.. charge with R-134a or Freeze12..

and dont change the oil to POE.. (still is mineral).

performance: lower, 134a vs R-12..maybe 10F warmer..

If R-134a in mineral oil, compressor will fail within

1 week (or may go a couple of years if oil was changed to POE).

Freeze12 in mineral oil may run 3-4 months before compressor

gets "dry" enough to fail.

Doing things EPA legal is a "bad deal" when doing a "proper"

conversion to R-134a or Freeze12.. Illegal topping off gets much

better performance and 5 years of runtime...

go figure..

--ghg, inventor of R-406A (autofrost) and R-414A (GHG-X4)

Soooo, i recovered about one can of R12, dropped in one can of R134a and guess what, the system is back to live.

ICCCCCCE cold.

The compressor is still fine, even though the system was running with that mixture for years and there was absolutely no residue in the hoses and pipes.

I tought this might be interesting for anybody having a R12 system with low refrigerant level.

The only problem i see is that the R134a might cause corrosion, i read somewhere that this might be an issue.

But again, on my LS it did not cause any problem so far.

I have to replace some O-rings soon and will switch to a Hydrocarbon Refrigerant.

It seems that the energy savings are amazing.

Already bought 5kg of R290 and R600a these two mixed at the correct ratio 80/20 should deliver a nice result.

Will post the outcome later :o

[smooth1]

Hello,

i am driving a 1990 LS400, in China, i love this car.

I bought it one year ago, last year the AC delivered ice cold air at max summer temperatures and humidity.

It gets hot and 100% humit here, crazy....

So this year i had to replace the compressor discharge hose and refilled the system with R12.

So far so good, the only thing i noticed was that the aircon did not blow as cold as before.

Low side and high side pressures were all within specs, strange.

Then i remembered that the previous owner told me his shop topped off the system with 134a..... back then i thought what the hack is he talking about.

Out of frustration i started to do some research and ohoooooo, found this Article:

Posted by George Goble on June 19, 1999 at 21:14:44:

In Reply to: Re: Replacement of R12 with R406a posted by John Strauss on June 16, 1999 at 16:07:09:

As you stated, the EPA has now made it "illegal" to mix

different refrigerants in cars.. Last time I looked, it was

still legal to mix 'em in stationary equipment.

R-406A in various mixtures with R-12 were run in a fleet of Humvees

early on (ambulance bodies).. R-406A by itself gives a 6-8F colder

duct temps than R-12, so with 50/50 R-12/R-406A the performance

gain was about 3-4F or 1/2 of using pure R-406A. (before EPA mixing

ban).

The "shocker" in illegal mixing is that mixing Freeze12, FR-12,

or just R-134a with R-12 (computer simulation on what happens)

start out with one slowly leaking R-12 system, gets down to about

50% remaining charge when the owner decides a recharge is needed.

1) Assume owner just "tops off" with R-134a (system has mineral

oil that R-134a will not "carry", but 50% R-12 remains, so oil

return to the compressor works fine. R-134a and R-12 form an

"azeotrope" with a boiling point of around -31F (R12 is -21.7F,

(R-134a is -14.7F, Freeze12 is around -8F) at 1 ATM. This

results in a performance improvment (capacity increase 25% or so)

along with slightly higher head pressures.. Performance gain

(over R-12) is about 2/3 of the gain of using 100% R-406A.

Freeze12 (80% 134a/20% 142b) is similar, except 2-3F warmer

than the above.. still much better than total R-12. This

"good performaning" mixture is called "contamination" by those

with vested interests in preventing it.

2) Next summer, system low again, user tops it off with R-134a,

now there is 25% R-12 (still enough to carry oil fine) and

cooling is still better than R-134a.

3) 3rd summer.. system low again.. tops off again with R-134a,

12.5% R-12 remaining.. still returns mineral oil fine.. cooling

now is about R-12 performance..

4) 4th summer...system low again.. tops off again with R-134a..

about 6% R-12 left, marginal mineral return, but probably

will work.. R-134a cooling performance..

5) 5th summmer.. top off again.. 3% R-12 left.. oil fails to return

compressor siezes up and fails.. IF using Freeze12 instead,

performance will be about +15F warmer than R-406A (autofrost)

Look how well this "illegal contaminated system" worked.

Now if legal...

1) remove all R-12.. charge with R-134a or Freeze12..

and dont change the oil to POE.. (still is mineral).

performance: lower, 134a vs R-12..maybe 10F warmer..

If R-134a in mineral oil, compressor will fail within

1 week (or may go a couple of years if oil was changed to POE).

Freeze12 in mineral oil may run 3-4 months before compressor

gets "dry" enough to fail.

Doing things EPA legal is a "bad deal" when doing a "proper"

conversion to R-134a or Freeze12.. Illegal topping off gets much

better performance and 5 years of runtime...

go figure..

--ghg, inventor of R-406A (autofrost) and R-414A (GHG-X4)

Soooo, i recovered about one can of R12, dropped in one can of R134a and guess what, the system is back to live.

ICCCCCCE cold.

The compressor is still fine, even though the system was running with that mixture for years and there was absolutely no residue in the hoses and pipes.

I tought this might be interesting for anybody having a R12 system with low refrigerant level.

The only problem i see is that the R134a might cause corrosion, i read somewhere that this might be an issue.

But again, on my LS it did not cause any problem so far.

I have to replace some O-rings soon and will switch to a Hydrocarbon Refrigerant.

It seems that the energy savings are amazing.

Already bought 5kg of R290 and R600a these two mixed at the correct ratio 80/20 should deliver a nice result.

Will post the outcome later :o

Ok, but that covers an R12 ac system with R134a added to it, but what about an R134a system and your adding R12 to it?

[billydpowell]

You would do well to read this article of a test on a Lexus:

http://www.autobodypro.com/safety/articles/0031.htm

partial read:

The EPA's ban on R12 production gave rise to a new generation of refrigerants. Now, blended versions of alternative refrigerants are wreaking havoc on vehicle A/C systems and shop equipment.

The windshield of a Lexus sedan hurtles across the hood of the car. All four side windows shatter, producing a shower of tiny glass fragments. Flames engulf the dashboard and sweep the head of the mannequin behind the wheel.

This fire erupted because the Lexus' air-conditioning system was charged with HC-12a, a refrigerant (produced by OZ Technology in Idaho) that contains propane and butane gas. The incident occurred during an event staged by the Palm Beach County Fire Department and the International Association of Arson Investigators, who demonstrated the dangers of replacing high-priced CFC-12 with cheaper, flammable substitutes--and illustrated the importance of using only refrigerants approved by the U.S. Environmental Protection Agency.

The EPA's 1995 ban on R12 production gave rise to an alternative refrigerant market--and to a problem for the automotive service industry. Ten approved substitutes are now available, but problems arise when these refrigerants--and/or Freon--are mixed within an A/C system. Combining refrigerants leads to cooling and operating problems, eliminates the opportunity to recycle any R12 in the system, taints good supplies of R12 already in shop tanks and contaminates recycling/recovery equipment. The substitute HCFC-22, commonly known as R22, causes additional problems because it destroys and leaks past A/C system seals and hoses, sometimes leading to plugged refrigerant circuits, reduced refrigerant flow and damaged components.

These problems are costly, but they are minor compared to the dangers posed by refrigerant alternatives or mixtures that contain flammables such as propane, butane and isobutane. Even more frightening is the fact that such cases of contamination are not rare. Even though the EPA prohibits the use of HC-12a in automobiles, OZ Technology President Gary Lindgren told a television news reporter from Phoenix that more than 5 million vehicle A/C systems operate on the refrigerant.

Overall, industry experts estimate that 3­15 percent of automotive A/C systems are contaminated with combinations of R12, HFC-134a, R22, hydrocarbons, propane, butane and isobutane. Neutronics Inc., an Exton, Pa.-based company that manufacturers refrigerant identifiers, predicts that 10­12 percent of vehicles serviced this summer will be contaminated. And because few automotive professionals or consumers are aware of the problem, that percentage is expected to increase.

[python]

r 134 takes pag oil and r12 takes another type, u can not mix the 2 or it causes the system to sludge up.....if u have mixed the 2 say bye bye to ur ac system

[roedel]

@Smooth1 You can't add R12 to a R134a system because R134a systems use a synthetik oil ,PAG, that would deteriorate in contact with R12.

I did not add any propane to my system, untill now:-) Just pure R12 and 134a.

That mixture is definately not explosive or flammable, Do not get irritated by Billy's Post above!!

But i certainly will add flammable and explosive Propane!

In Australia it is a very common thing, especially for taxis due to the fact that 134a cools much worst in the hot australien summers and because R134a is basically a well established ripoff by Du Pond with nothing but technical disadvantages and a high price. http://www.hychill.com.au/tech/facts.htm

Of course they keep their propaganda machine going, propane is a to cheap and easy to get replacement.

Did you know that basically all fridges and heat pumps in europe run on propane (R290) with a 25-30% higher efficiency?

When the first companies started using propane in their friges in germany the refrigerant industrie claimed people would install a bomb in their kitchen by buying that fridge..... LOL

Further, the quantity required to replace the original R12 or 134a is about a thrid (by weight) when using propane.

Thus the LS400 takes about 1,000 grams of R12, The refill with propane 350 grams.

350 Grams fit into a coke bottle, i can't see how that small ammount of gas could possibly create disaster. Especially if you consider the fact that you have 15 gallons of high flammable gasoline behind your rear seat.

[SRK]

Roedel

My 92 is converted properly to R134a, and the system works just fine. Cools very well. My 98 came from the factory with 134a, as did all cars from 1993, and it cools very well. So the idea that 134a is a "DuPont" conspiracy is ridiculous. You've spent far too much time in commie-pinko-land.

The chemistry of refrigeration has been understood by those who work in the industry for years. And propane and butane while acting as refrigerants, as many compounds do, are unsafe and incompatible with system lubricants.

However, I hope you continue with propane - you deserve it.

[billydpowell]

Roedel

My 92 is converted properly to R134a, and the system works just fine. Cools very well. My 98 came from the factory with 134a, as did all cars from 1993, and it cools very well. So the idea that 134a is a "DuPont" conspiracy is ridiculous. You've spent far too much time in commie-pinko-land.

The chemistry of refrigeration has been understood by those who work in the industry for years. And propane and butane while acting as refrigerants, as many compounds do, are unsafe and incompatible with system lubricants.

However, I hope you continue with propane - you deserve it.

I couldn't have said it better.. as the British would say "CHEERS"

[roedel]

SRK,

come on, i thought his is a discussion board.

I advise you do some research about the efficiency, dangers and environmental impact of R134a before writing offensive statements. Maybe you start just by comparing it to R12.

Further, Propane mixes just fine with all kinds of lubricants, there is plenty of reliable and easy to find prove out there.

If you are able to understand the technology behind it you will realize who really lives in "commie-pinko-land". ;)

But to be honest, i have been missguided as well, i am a ASE certified master technician, my team and i converted hundreds of Ac's to that 134a junk over the years.

Understanding does come by education and intelligence. You apply or accept acquired knowledge to your education and it develops UNDERSTANDING.

[smooth1]

Alright guys, let's keep this conversation civil. ASE techs and regular people alike can come here to learn a few things from others experiences. I already knew the answer to the question I asked , I was just trying to find out how much you knew about freon systems first. I've always been straight out of the book when it comes to certian systems like a/c. But I hear alot of talk by others mixing down R134 and adding what sounds to me like crazy gases to produce better results. But when I talk to whom I consider to be HVAC pros, who have been in this feild for 20+ years I always hear the same answer. Don't mess with it. We've allways figured if it was that safe, and that great to use, then why wouldn't the developing engineers just use that instead. There must be some trade off/risk that makes those results not worth it. Does anyone here have experience with the new Puron systems? or 410a?

[smooth1]

roedel,

We have a nice use for propane here that I hope you get to experience over there in China. The BLU-96 Fuel Air Explosive. Many versions are out there and it is very effective using propane type fuels. The Taliban don't like it one bit, for some reason.

I suggest roedel does some tests for us and vent the propane into the cab of his car to simulate a coolant leak in the cabin.

Make sure to light your cigarette after you know the doors and windows are closed and the cab is saturated, because that is what is going to happen when the expansion valve fails in your car whilst going down the road having a smoke.

ASE mechanic? Did you buy the certificate the same place you got your Chinese rip offs of patented products?

The post seems more like a political statement against democratic countries and free enterprise.

I'd vote to ban the guy if he keeps recommending dangerous retrofits like this one.

Safety First in the Free World buddy!

I'm going to ask you to keep the banter out and keep politics out of this. I've been reading the same thread you have and other than where he/she is from, no one has brought up any foreign observations than you.

With that being said, the points you make about how dangerous this is are very valid. Not to mention a slew of other issues your dealing with here.

[smooth1]

Yeah, this thread is closed.

[bartkat]

The below listed Moderator just PM'd me that I am the problem it seems.

This P.O.S. from China with 3 posts gets on here and tells us that our countries products are junk and we should put explosive gas in our ac units.

Unless this Moderator apologizes to me immediately I will never visit this URL again.

Cool it? I am not your child buddy.

Got it?

This guy brought up politics by saying DuPont has a conspiracy in how they sell refrigerant.

Dupont is and AMERICAN company and this joker is spouting off about our products from a COMMUNIST country and you support him?

Type real hard and real fast?

I hope you live near my winter home in Boca Raton, because me and my husband would love to come talk this over with you!

Talk cars and shop on this board?

Read some of my posts idiot before you write junk like that. I'd start with my timing belt series.

Let me know when was the last time YOU changed one on your own, IN YOUR OWN GARAGE!

Hell hath no fury...

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Resident Gearhead

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If you want to argue politics go to a political forum and type really hard and fast. Get it off your chest. But this is a Lexus car forum. We talk shop and cars here.

Yes it is a car forum, not to be taken so personal.