Refrigerant and rebuilding AC (In defence of Durocool)

[Robert Myers]

--
[ Picked text/plain from multipart/alternative ]

IIRC, George Goble (not the comedian so popular in the 60's) is in the
business of selling flammable AC components.  Perhaps that's enough said.

Yes the point that a large volume of exceedingly flammable gasoline is in
the fuel tank of your car and can, under certain circumstances, pose a
significant fire hazard is valid.  Gasoline, however is not normally
connected directly to a clear and open pathway into the interior of your
vehicle.  Perhaps this refrigerant is not a _significant_ hazard as you
suggest.  However, it is a hazard which is easily avoided simply by using a
non-flammable (and also non-toxic) refrigerant.

1.5 pounds (say 750 grams - that's a low estimate) of butane (at 58 grams
per mole) is nearly 13 moles of butane.  One mole of butane will occupy
approximately 22 liters (22.4 liters at STP) of volume at 100%
concentration (depending on temperature and pressure).  13 moles (at 100%
concentration) will occupy approximately 290 liters.  A 9.1% concentration
of butane in air is an explosive mixture.  These 290 liters of pure butane
gas are sufficient to produce approximately 3200 liters of (a 9.1%)
explosive mixture when mixed with air.  (All numbers are only approximate
but are reasonably close.)

Now, let's see...  What do you suppose the volume of the interior of my car
is?  A space measuring 2 meters by 3 meters by 1.5 meters will contain 2100
liters.

I don't want it in my HVAC system - certainly not since there is a readily
available and comparatively safe alternative.

At 08:27 AM 6/13/2003 -0400, santoli9 at cox.net wrote:

>You might find George Goble's take on this interesting. The full text is
>at http://www.yarchive.net/ac/politics.html
>I've extracted a bit here:
>
>There is some flammability risk for running pure hydrocarbons
>(propane/butane, etc) in automotive A/C.. but it is pretty small.
>OZ-12 (propane/isobutane) was installed in 50,000 cars with no
>fire/safety problems reported.. until somebody "rigged" a controlled
>demo, where 3 cans of it were released (took several tries) in a sealed
>car passenger compartment, and recirulated until the correct fuel/air
>mix was obtained.. and BOOM.. it did blow up.  Film at 11.. went to
>CNN, etc.. which pretty much got it banned.  Using the fear of fire
>in a non scientific manner to fear-monger the public.. Remember the
>Hindenburg, the Pinto, The side mounted Pickup truck gas tanks, etc..
>(remember the rocket engine ignitors?? on the truck blowing up?)
>
>The A/C only holds 1.5lbs or so of propane/isobutane.  The gas tank
>holds over 100lbs of gasoline.  Oil, brake fluid, transmission fluid,
>power steering fluid, are all EXTREMELY FLAMMABLE/EXPLOSIVE when they
>drip on hot enging/exhaust components. Hydrocarbons have to be at a fuel/air
>ratio of roughly between 2% - 8% by volume in air in order to ignite.
>
>In a hose break/leak, propane/butane dissipate rapidly, gasoline
>hangs around, fuming, waiting for an ignition source.
>R-12 systems contain approx 10-15% by volume of mineral oil, which
>is dissolved in the refrigerant.  A line rupture creates in "oil fog"
>which can be quite explosive.  A jet of R-12/oil mist leaking can be
>ignited (I have a pix) and does sustain fire (looked like a flame-thrower).
>That is why "those in charge" are VERY CAREFUL to specify flammability
>specs WITHOUT the oil present, rather that what is really found in
>a car A/C.  When you include the compressor oil, all the refrigerants burn.
>
>Also, many common "tire inflator/sealer kits" use propane
>and butane, and it is mixed with AIR UNDER PRESSURE in a TIRE.. and
>this IS A BOMB by definition.  How come nobody raises much ruckus over
>tire inflators, R-12 and oil burning, etc.  Those things do not have
>the power to prevent the sale of millions of "extra" new cars like the
>alternative refrigerants do (when the R-12 is gone). R-134a does become
>flammable at just above atmospheric pressure (5 PSI).  There have been
>reports of R-134a explosions in refrigerant lines/compressors.. Workers
>unsoldering lines (had air/R-134a in them), after letting out the
>refrigerant, built up a small positive pressure, or the burning of
>the oil at the joint raised the local pressure above 5 PSI, and blam.
>Go figure for yourself.
>
>
>
>
>---
>Incoming mail is certified Virus Free.
>Checked by AVG anti-virus system (http://www.grisoft.com).
>Version: 6.0.489 / Virus Database: 288 - Release Date: 6/10/2003

_____

One nation, under surveillance. :-(

Bob
*****
  Robert L. Myers  304-574-2372
  Rt. 4, Box 57,  Fayetteville, WV 25840 USA  WV tag Q SHIP
  '95 urS6 Cashmere Grey - der Wunderwagen   ICQ 22170244
  http://www.cob-net.org/church/pvcob.htm
*****
--