Using R-12 in R134a system
nov...@zip.zip
Forgive my ignorance, but I have read many FAQ's and they only seem to
deal with retrofitting R-12 systems with R-134a
What are the major problems I will have using R-12 in a system
designed for R-134a? I have all the equipment necessary but only an
old R-12 cannister. I would like to use it if possible.
R-12 sounds easier to pump, but the lubricants sound like a problem
though... anyone?
Thank you,
David L.
AMBIENT CONTROL
dear david
from what i understand it should be okay to put r12 in a 134a system the
oil is okay going that way-not possible in reverse.
as for 12 being easier to pump-don't know quite what you mean
richard
Panmetron
> David L. wrote:
>What are the major problems I will have using R-12 in a system
>designed for R-134a?
Well lets take this step by step:
1) Oil - R12 is compatible with the PAG and Ester oils used
in New and Retroffited R134A systems.
2) R12 is compatible with seals and decissant used in R134
systems.
3) R12 does take up less volume, retrofits call for the amount
of R134a used to be 90% of the R12 Spec. Guess you could
reverse that calc.
4) R134a requires and systems have a slightly larger condenser
which is OK with R12.
5) Compressor is compatible since pressures and compression ratios are similar
Cost is the only factor I see, R12 if much more expensive but
if you already have it then thats not a factor.
I have not heard or read of any EPA rule that says you can't use
R12 in any automobile application.
Gee sounds like a winner.
Anyone else got an opinion ?
Thank....
Greg
JimLavL
>> David L. wrote:
>>What are the major problems I will have using R-12 in a system
>>designed for R-134a?
R-12 is generally compatible with all the parts, pieces, and oil in a 134a
system. The biggest difference will be "size" of the system. R-134a systems are
larger than R-12 systems for the same job. A 1 horsepower R-134a compressor has
more displacement than a 1 horsepower R-12 compressor, so if you switch gas you
will get more cooling out of the new arrangement. Will this overload the motor?
Will you cycle too much? Depends on the system.
I agree with all the previous comments - the biggest drawback is cost of
refrigerant. But if you have 12 to get rid of, and want to do a few 134a units
with it, go ahead.
Laugh Big
Yes what you might want to do is dump the R 12 and use R 409A it works very
well.
Laugh Big
You can get R 409A for about 170 dollars for 30 lbs.
Laugh Big
My experience using R 409A works very well in an old R 12 system and did not
have to change one part. Make sure first to dump the old R 12 though before
adding the new.
Laugh Big
Does anyone else have any experience with R 12 substitutes.
Mitchel
Stay with R-12 if you can.... You'll be alot happier... You lose efficiency
with R-134a
Mitchel
Walter L. De Visser, Sr
Laugh Big <laug...@aol.com> wrote in article
<19971221074...@ladder01.news.aol.com>...
> Does anyone else have any experience with R 12 substitutes.
>
Don't understand why anyone would want to change from 134 to R12. Sell the
R12 and use the R134A.
All the substitutes seem to work well. I have used most of them including
the 400 series and the 500 series. I like the 500 series best but R134a
works just fine.
Walt
Ron Henley
I'm curious why would anyone suggest to stay with R-12?
1.The original posted question was asking about putting r12 in a 134a
system.
2.A system designed for 134a will not run any more efficent with R12 in it,
in fact you
will have to add a additional amount of R12 to meet specs.
3.I will agree you do lose a little efficiency when putting 134a in a R12
system, but
since this is a retrofit what do you expect.
Just my opinion
Thanks, Ron
Mitchel <mit...@baldcom.net> wrote in article
<349db...@news2.lightlink.com>...
John
Ron Henley wrote:
>
> I'm curious why would anyone suggest to stay with R-12?
> 1.The original posted question was asking about putting r12 in a 134a
> system.
> 2.A system designed for 134a will not run any more efficent with R12 in it,
> in fact you
> will have to add a additional amount of R12 to meet specs.
> 3.I will agree you do lose a little efficiency when putting 134a in a R12
> system, but
> since this is a retrofit what do you expect.
> Just my opinion
> Thanks, Ron
Hi Ron,
1) You're right, the original posted question was asking about R12 to be
added into a R134a system. I think that the original poser who posted
this question will be at a loss.
2) I would suggest also that the poser ( I am unable to find his name,
sorry) to purchase a cylinder of R134a instead which solve the whole
problem or uncertainty.
Regards,
John
GS7346
Maybe some of these techs are just trying to keep people on R-12 to get the
final bit of stock out of here and move on to the friendly stuff.
Just joking guys.
Thomas Perry
Buy a bottle of hot shot. It is the only drop-in replacement for 12 0r 134a.
It also does not require a oil change. Works great.
Walter L. De Visser, Sr wrote in message
<01bd0e80$7f77c3c0$9d6f...@brcc.cybersol.com>...
Marc O'Brien
Ron Henley <rd...@hcis.net> wrote in article
<01bd0e82$ec757560$9ba551d1@ron>...
: I'm curious why would anyone suggest to stay with R-12?
You looking for an absolute?
: 2.A system designed for 134a will not run any more efficent with
R12 in it,
: in fact you
: will have to add a additional amount of R12 to meet specs.
R12 should probably be more efficient but the expansion device would
be required to allow more liquid mass through. Generally R134a is
only more efficient than R12 if liquid subcooling is enhanced due to
it's greater liquid specific heat value. To tap into this subcool
related increased efficiency then greater amounts of R134a are added.
JimLavL
"Thomas Perry" wrote:
>Buy a bottle of hot shot. It is the only drop-in replacement for 12 0r 134a.
>It also does not require a oil change. Works great.
Hot Shot contains the same ingredients as R-409A (R-22/124/142b), plus about 2%
hydrocarbon. The hydrocarbon doesn't do much for the oil return, when you
compare the miscibility curves. The hot shot does have less R-22, which makes
it work better in cars, but not refrigeration systems.
In other words, buy the 409A instead - you can get it many more places and save
yourself a few hundred bucks a jug for the same thing.
TKMan
Alternate to your refrigerants is R-401B. Has higher head pressure, but very
good for lower temperature systems, i.e. coolers working at -10 to 50 degrees.
Not good for auto use.