[AT] R134a

[Mark Johnson]

There is one problem with Red Tek 12A - which you already touched 
on...flammability. The propane+n-isobutane mix has been known for a good 
many years - it has all the same useful properties as R-12 - almost 
identical eutectic curve, carries oil through the system, and so on. My 
dad (a 1950 engineering graduate) apparently took a 'practical 
thermodynamics' course where they spent a lot of time studying 
properties of gases that would be useful as refrigerants. Even as early 
as the late 1940's, hydrocarbon gases like propane were known to be 
useful - but the available gasket and seal technology meant that they 
were too hazardous to use in commercial environments. [As an engineer, 
Pop was responsible for maintaining the chiller systems for milk and ice 
cream production at a dairy plant, from about 1952 to 1963.] Propane 
might have been better than ammonia, even then - but small ammonia leaks 
are easily detectable, and the stuff doesn't explode!

I can remember when those 14 oz cans of R-12 were 59 cents at 
K-Mart...the stuff was cheaper than bottled water. Anybody who could 
read a gauge set and turn a wrench could recharge their own A/C - which 
no doubt contributed to the 'escape' problem,  as it was cheaper to 
recharge the system once a month than to go get it fixed.

Mark J
In snow-covered Columbia, MO - 16 inches of heavy, wet stuff that I have 
to shovel today. No telling when the city will actually plow our side 
street - 3 blocks of deep snow to get to a main route designated as 
'snow route' - and our cars will just high-center if we try to get out!


On 1/12/2019 5:54 PM, Cecil Bearden wrote:
> I have recharged a lot of r-12 systems with Red Tek 12A.  They have 
> changed it somewhat to another name, but another brand is Freeze-12.  
> works good in r-12 systems better than R134A.  It has propane and 
> n-iso butane in it.  Pure propane will also work, but the possibility 
> of fire limits its use to stationary refrigeration systems.   Once I 
> bought some replacement refrigerant that was supposed to be the same 
> thing as Red Tek and spent $300 on parts and 3 days to make a van blow 
> cold air.   Got rid of the new stuff and went back to R134a and it 
> worked fine.  Had a leak later and filled it with Red-Tek and it would 
> frost the windshield.  Feds imposed a floor tax of $25/lb on R-12.  If 
> you have a jug of it, Uncle Sam wants his floor tax..... I wish I had 
> bought a pallet load of R-12 back when it was $20.lb
> Cecil
>
> On 1/12/2019 5:12 PM, Steve Offiler wrote:
>> R134a is crap?  Really?  My ‘97 F250 had an R134a system that would 
>> still make icicles in the cab when I sold it 19 years later.  Zero 
>> work ever done on that system. 2003 Focus, system worked fine when 
>> sold in 2014.  Zero work on it.   Wife’s ‘01 Honda CR-V, 210,000 
>> miles, ditto. Blew cold air until the day we sold it, never worked on.
>>
>> Now, i would not be surprised to learn that the conversions from R12 
>> were somehow lacking, if that’s what you mean.
>>
>> SO
>>
>> Sent from my iPhone
>>
>>> On Jan 12, 2019, at 2:46 PM, <bloomis at charter.net> 
>>> <bloomis at charter.net> wrote:
>>>
>>> In the early 90s. Part of the reason I left the commercial 
>>> refrigeration
>>> trade. The transition from fluorocarbons to all the alphabet soup of
>>> refrigerants today was a real pain. Went to Ammonia refrigeration. Much
>>> easier. I still have a 30# of R-12. Well I guess it's a 29.5 since I
>>> recharged my daughter's Saab long ago. 134a is crap. Contractors 
>>> made a lot
>>> of money replacing compressors. Auto A/C worked way worse. But autos 
>>> were
>>> the chief culprit of refrigerant into the atmosphere. Not the ice 
>>> machine
>>> with 1000lb charges, but the how ever many hundred million leaky autos.
>>> Bradford
>>>
>>> -----Original Message-----
>>> From: AT <at-bounces at lists.antique-tractor.com> On Behalf Of James Peck
>>> Sent: Saturday, January 12, 2019 11:08 AM
>>> To: 'at at lists.antique-tractor.com' <at at lists.antique-tractor.com>
>>> Subject: [AT] R134a
>>>
>>> Is R134a the refrigerant currently used in the air conditioning of ag
>>> equipment. When was R12 fhased out.
>>>
>>> https://www.natex.org/site/391/Careers-Learning/The-NATE-Magazine
>>>
>>> https://harryferguson.blogspot.com
>>>
>>>
>>>
>>> _______________________________________________
>>> AT mailing list
>>> AT at lists.antique-tractor.com
>>> http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
>> _______________________________________________
>> AT mailing list
>> AT at lists.antique-tractor.com
>> http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> _______________________________________________
> AT mailing list
> AT at lists.antique-tractor.com
> http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com