A/C converson from Freon to R134- Necessary?
Rudy Chukran
whichs are found primarily in autos, has me concerned about when
or whether I should buy a new car with the nonCFC (R134) based
air conditioners. Or more precisely , should I buy one with
the oldstyle R12 system for fear of rapid inability to service it?
SO, anyone have any opinions about these questions?
What exactly does the federal law say about Freon?
Will R12 (Freon) become completely extinct after 1994?
If not, will its cost become completely prohibitive?
If so, should I refuse to buy an auto with a R12 A/C for fear of
not being able to service it in 1995?
What is a typical conversion cost from R12 capable to R134 capable?
What parts are replaced?
--
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Rudy Chukran | EMAIL:
IBM AIX Technical Consulting| RSCS: CHUKRAN at AUSTIN
11400 Burnet Rd. |
Daniel J. Stern
tapered off by '95 or '96. And the large containers are available to the
uncertified only until 15 November 1994, so hurry.
SL6 Dan
On 18 Oct 1994, Manly Matt Schulman wrote:
> chu...@austin.ibm.com (Rudy Chukran) writes:
>
> >The federal ban on Freon and freon based air conditioning units,
> >whichs are found primarily in autos, has me concerned about when
> >or whether I should buy a new car with the nonCFC (R134) based
> >air conditioners. Or more precisely , should I buy one with
> >the oldstyle R12 system for fear of rapid inability to service it?
>
> First of all, no new car sold in the US market has R12 AC. That's a
> federal law. R134 has a lower heat capacity than R12, so either your new
> car will have a bigger AC system (bigger compressor = more HP drain) to
> compensate, or it simply won't cool as well.
>
> >What exactly does the federal law say about Freon?
> >Will R12 (Freon) become completely extinct after 1994?
> >If not, will its cost become completely prohibitive?
> >If so, should I refuse to buy an auto with a R12 A/C for fear of
> >not being able to service it in 1995?
>
> R12 is no longer being produced, by federal law. There are stockpiles of
> it available, but it is no longer available in small containers to
> unlicensed consumers. R12 will become more expensive as it becomes a
> rarity, via market economics. It shouldn't be a problem for the next few
> years, but expect to pay >$100 for AC service before the end of the decade.
>
> Note that *large* containers [>20 lb] are still legally available to
> unlicensed consumers - you figure that out! It might be a good purchase,
> though expensive, if you plan to keep an old car.
>
> >What is a typical conversion cost from R12 capable to R134 capable?
> >What parts are replaced?
>
> Basically, you need a larger compressor, and EVERY piece of rubber has to
> be replaced with neoprene because R134 is big-time corrosive. You'll also
> nee a larger condenser and evaporater. The cost may well approach that of
> a decent used car.
>
> That's the story - sorry to be the bearer of bad tidings!
> _____________________________________________________________________________
> These words of wisdom from: _____
> "Marvelous" Matt Schulman / \
> [schu...@nova.gmi.edu] --------/--------/ \
> ( / )
> ( / )
> \ /--------/--------
> \ _____ /
>
>
>
Gordon McKenzie
>> >What is a typical conversion cost from R12 capable to R134 capable?
>> >What parts are replaced?
>>
>> Basically, you need a larger compressor, and EVERY piece of rubber has to
>> be replaced with neoprene because R134 is big-time corrosive. You'll also
>> nee a larger condenser and evaporater. The cost may well approach that of
>> a decent used car.
>>
I've been told that EVERY piece of the system nust be replaced. The reason
given is that the R12 and the R134 are violently incompatible.
Now, having said that, I can't remember where I heard that, so please take it
with a grain of salt.
Padgett 0sirius
>Point of clarification--R12 is still being produced, and it will be
>tapered off by '95 or '96. And the large containers are available to the
>uncertified only until 15 November 1994, so hurry.
Along these lines, anyone know what the status of the R-406a direct
replacement for R-12 is ? Was announced some months ago but have seen
nothing since.
A. Padgett Peterson, P.E.
Cybernetic Psychophysicist
We also walk dogs
PGP 2.7 Public Key Available
Daniel J. Stern
Manly Matt Schulman
>The federal ban on Freon and freon based air conditioning units,
>whichs are found primarily in autos, has me concerned about when
>or whether I should buy a new car with the nonCFC (R134) based
>air conditioners. Or more precisely , should I buy one with
>the oldstyle R12 system for fear of rapid inability to service it?
First of all, no new car sold in the US market has R12 AC. That's a
federal law. R134 has a lower heat capacity than R12, so either your new
car will have a bigger AC system (bigger compressor = more HP drain) to
compensate, or it simply won't cool as well.
>What exactly does the federal law say about Freon?
>Will R12 (Freon) become completely extinct after 1994?
>If not, will its cost become completely prohibitive?
>If so, should I refuse to buy an auto with a R12 A/C for fear of
>not being able to service it in 1995?
R12 is no longer being produced, by federal law. There are stockpiles of
it available, but it is no longer available in small containers to
unlicensed consumers. R12 will become more expensive as it becomes a
rarity, via market economics. It shouldn't be a problem for the next few
years, but expect to pay >$100 for AC service before the end of the decade.
Note that *large* containers [>20 lb] are still legally available to
unlicensed consumers - you figure that out! It might be a good purchase,
though expensive, if you plan to keep an old car.
>What is a typical conversion cost from R12 capable to R134 capable?
>What parts are replaced?
Basically, you need a larger compressor, and EVERY piece of rubber has to
be replaced with neoprene because R134 is big-time corrosive. You'll also
nee a larger condenser and evaporater. The cost may well approach that of
a decent used car.
That's the story - sorry to be the bearer of bad tidings!
George Goble
>In article <Pine.SOL.3.91.941018122134.20116B@gladstone> "Daniel J. Stern" <das...@gladstone.uoregon.edu> writes:
>
>Along these lines, anyone know what the status of the R-406a direct
>replacement for R-12 is ? Was announced some months ago but have seen
>nothing since.
>
R-406A (GHG R-12 Substitute) is on the market and EPA approved for
most uses EXCEPT CARS and "MVAC" (motor vehicle A/C cars, tractors, etc).
It is legal to cool the cargo in a refrigerated semi, but not to cool
the driver. R-406A is avail to the end user (service person) from
Monroe Air Tech (800) 424-3836, McMullen Oil Products (800) 669 5730.
Wholesalers can get it from Indianapolis Refrigeration Products
(800) 497 6805. R-406A may be legal in cars outside the USA though.
It was run in 2000 or so cars during early testing 1990-1993 and
worked fine. Higher leakage occurred in "nitrile" hoses. "Barrier"
(nylon lined) hoses, which replacement hoses are and GM, etc, have
used for years, worked fine with no more leakage noticed than R-12.
My personal car has had R-406A in it since Aug 1990 and it still
works fine. R-406A purchased after 2/14/94 is not legal for cars,
but purchased before that it is ok for cars.
--ghg (inventor of R-406A)
www homepage: http://ghg.ecn.purdue.edu/
George Goble
Most of this is BS from people who want to sell you new parts or new
cars.. R12 and R134a can even be mixed and work fine. (in an R12 system
with mineral oil).. you should have at least 30% R12 to provide oil
return though. The auto industry had lobbied to get new laws (now in
proposed rule making @ EPA) which will soon make it illegal to mix refrigerants
for automotive use. Don't put any R-12 in a native R-134a system or
the PAG oil will self-destruct. 50-70% R-134a in an R-12 system with
mineral oil should be ok.
If the system has 100% R-134a in it, mineral oil won't work, since
it doesn't dissolve in the refrigerant (miscibility) and may not
return to the compressor correctly.
The auto industry mostly uses "PAG" oils for new and retrofit
R-134a systems.. This oil is quickly destroyed by residual CFCs
(like R-12 and R-11 "flush").. Even small traces of "chlorides"
left on the inside of pipes, etc, of an R-12 system, can destroy
the PAG oils.. The oils are destroyed, not the R-134a.. so this
is the reason to change all the parts.. (most people will trade for
a new car when they see the estimate.. probably the intended goal).
POE (polyol ester) oils are more tolerant of residual chorides,
but they are VERY moisture sensitive and offer less lubricity
than R-12 mineral oils.. The stationary industry is using POEs
for R-134a.. some segments of the stationary industry are
doing massive recalls on newly built R-134a equipment, others
are doing fine.. Lots has to do with the variety of oil, and
cleanliness of assembly, moisture present, etc.. Some of the automotive
R-134a retrofit kits use POEs.. they should do better than PAGs.
POE oils are catalyzed into breakdown by steel and heat.. so
inhibitors are added to try to prevent this.. so now all these
secret proprietary "additive" packages are showing up in
various oils.. some work, some don't.. it will be a few
years before this is all sorted out. This is why R-406A
was designed to run in simple mineral (R-12) oils.. no
oil changes needed.
R-134a has a lower "critical" temp than R-12. Critical temp
is the temp (and above) at which a gas cannot be liquified
or condensed, no matter what the presure is. Critical temp
for R-12 is 234F.. and R-134a is 214F. At critical temp,
the corresponding critical pressure (if you have liquid
present) will be in the range of 580-600 PSIG for both of them.
From doing experiments, I have found that automotive A/C
condenser temps of around 212F do happen.. since it is bolted
on the the radiator.. which gets hotter than that.
Car not moving, poor air flow, etc... all kill a
R-134a system much more than R-12 (or other refrigerant)
system. At 214F, R-134a will not even condense and be
at 588 PSIG or such.. so the system will pretty much
cease to function, bust hoses, compressor valves, etc.
R-134a needs a much bigger condenser, higher air flow rates,
and ways of getting cooler air due to the low critical temp.
--ghg