[alfa] Re: Air conditioning question (No Alfa content)

[Joe Elliott <jee@xxxxxxxxxxxxxx>]

I've done the research.

The refrigerants I advocate may be illegal in
Arkansas, Arizona, Connecticut, Florida, Idaho,
Indiana, Iowa, Kansas, Louisiana, Maryland, North
Dakota, Oklahoma, Texas, Utah, Virginia,
Washington, Wisconsin, and the District of
Columbia, but no one's going to pull you over and
sample your refrigerant.  Post-1972 headlight
lens designs are also outlawed in several states,
but that doesn't stop me from using them, because
I'd rather get cited than die in an accident that
could have been avoided.

The fire risk is (like USA headlight laws) mostly
BS.  If you test pure refrigerants in a lab,
you'll discover that R-134a has an autoignition
temperature of 1411F, which is lower than the
1585F at which the equivalent hydrocarbon
refrigerant ignites.  On the other hand,
hydrocarbon refrigerants will ignite more readily
in the presence of an open flame than will
R-134a.  But both of those facts are really
beside the point.  In your car's air conditioning
system the refrigerant is mixed with flammable
oil, and that's where the fire risk comes
from--it's independent of your refrigerant
choice.  But don't take my [theoretical] word for
it.  See Colbourne, D., 1997, "Calor Gas Internal
Appliance Fire Test Report."  To make a long
story short, he applied heat to two refrigerators
using the two afformentioned refrigerants and
concluded that in both cases "an intense fireball
was produced
Regardless of the type of
refrigerant used, flame jets tended to die out
rapidly and minor flames that remained were
evidently burning residual compressor oil."  Keep
in mind that his control subject was a
refrigerator using the technically non-flammable
R-12, and still, "an intense fireball was
produced."  Given the explosive potential of all
air conditioning oils, it's no surprise that the
same guy (with T. J. Ritter) concluded in a 1998
paper that "The conclusions...are that the use of
hydrocarbon refrigerants does not significantly
increase the potential for fires or fatalities."

The only logical reason to choose R-134a is if
you rely on professionals to service your air
conditioning--it's true that most shops won't
mess with anything besides the traditional R-12
and R-134a.

R-12 may last longer and work better than R-134a,
but hydrocarbon refrigerants aren't any more
likely to sneak through your hoses and seals than
is R-12.  And they will cool your car just as
effectively as R-12, while consuming less energy.
(Last summer when I had a thermocouple in the
car, I saw 4 degrees Celsius at the vents in my
'82 GTV-6, on an 85 degree Fahrenheit day--the
only modification besides the refrigerant was a
Milano compressor.)  For my money, the real
beauty of hydrocarbon refrigerants is that
they're indifferent to the oil you use in your
compressor, are compatible with all compressors,
hoses, and seals, and can even be mixed (albeit
not legally) with traditional
refrigerants--legalities aside, you don't
actually have to *convert* anything to use a
hydrocarbon refrigerant, so you can switch back
any time you want.

Just my two cents,
Joe Elliott


At 6:17 PM +0000 8/3/04, alfa-digest wrote:
> Date: Tue, 3 Aug 2004 13:20:24 EDT
> From: AlfaRs@domain.elided
> Subject: [alfa] re: Air conditioning question (No Alfa content)
>
> Before anyone decides to use one of the HC refrigerants I suggest they
> do a little research.  They are actually outlawed in several states.  The
> problem is that they are pretty flammable.  You have to remember that we
> are talking about a flammable gas under pressure (up to 300 psi on a normal
> system).  The big concern is that in an accident you have an evaporator in
> the passenger compartment carrying this flammable gas!  I'm not saying that
> this stuff doesn't work, or that it isn't much better on the environment, or
> even
> that I wouldn't use it myself but you need to do some research prior to use.
> You will also find that most AC shops will not work on your system if this
> stuff is installed.  The two links below are very good for general AC
> information.
> Both are supported by professionals.  You will see that they both recommend
> 134a over any of the blends or HCs.  There is no miracle in a can when it
> comes
> to AC.  As for the original question about the Jeep pay a few extra bucks
and
> stay with the R12.  Trust me it will work better, last longer, and you can
> always
> convert at a later date
>
> http://www.ackits.com/forum/index.cfm?NoCookies=Yes&forumid=1
> http://www.aircondition.com/
>
> Dave McCrory
> Maryville, TN
> 93' 164 (freeze 12)
> 87' Verde (R12)
> 87' Platnium (R12)
> 87' Gold (empty)
> 76' Spider (2x70)
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