From: John De Armond
Newsgroups: rec.autos.tech
Subject: Re: Enviro-safe refrigerant
Date: Tue, 17 Apr 2001 03:26:47 -0400

Robert Hancock wrote:

> Thing is, the gas isn't routed through the passenger compartment like the
> A/C lines are to the evaporator. I was reading something on Delphi
> Automotive's site where it talked about some research they were doing using
> flammable/toxic, but non-ozone-depleting and non-global-warming-causing
> refrigerants for cooling, but then using a heat exchanger system to cool off
> the passenger compartment with something else in between to eliminate the
> risk to the passengers..

Contemplate driving around with a couple of cans of aerosol paint in
the floorboard or starting fluid in the trunk.  In either case,
there is more flammable propellant (isobutane, usually) in little
steel foil cans laying loose there in the floor than would be in
your AC.  Propane/isobutane is a little more than half as dense as
R-12.  That means that if you have a HUGE system like the one on my
68 Fury which holds 3 lbs of R-12, you'd have about the same amount
of flammable gas in the spray cans as you would in the system.

Now contemplate having 80 or 100 or more lbs of flammable liquid in
a tin can behind your backside.  That's what the gas tank is.  And
unlike propane, when gasoline gets spread around in a crash, it
hangs in there and burns for a LONG time.

Back when I owned a welding supply wholesaler that also sold
propane, I'd take the old, leaking propane tanks that I was required
to confiscate, perforate and dispose of out to the range and
perforate them with a .300 win mag from about 300 yards. After
filling them with propane, of course :-) With smudgepots burning
nearby, this makes a neat little FAE.  While spectacular, it is
NOWHERE NEAR as spectacular as taking an old , full fuel tank out,
putting some dynamite under it and popping it.  The fireball is
larger and the residue lays around and burns for many minutes.  The
propane event is over with almost as quickly as the fireball
dissipates.

The flammable hysteria is the result of a skilled campaign by MACS
(mobile AC society, the PAC for the automotive AC aftermarket/repair
market) to discredit the flammables because it threatened what was
then perceived as the veritable pot of gold in retrofits.  Back in
the 90-92 timeframe when George Goble, myself and others were
working on alternatives, the consensus was that retrofitting for
R-134a would cost around a thousand bux.  It still does if you do it
right.  Simple drop-ins would have destroyed this pot of gold.
'Specially when this computer nerd (George Goble) held a key
patent.  Macs did things that would have made 20-20 and their rocket
motors on the gas tank stunt proud.  In one instance they made a
video tank purporting to show a car blowing up from a flammable
refrigerant leak.  Turns out they had to put a 20 lb propane tank
with the valve open in the vehicle to get enough propane to explode.
Once you get used to it, it's easy to pick out MACS propaganda
verbiage.  Really makes me sick to hear said verbiage from some
counter guy or mechanic, for I know they've bought the MACS
propaganda hook, line and sinker without actually thinking about the
issue.

Flammables weren't the only ones MACS went after.  They went after
George's R-406a drop-in R-12 replacement with a vengeance, using
their bought-and-paid-for EPA to keep him off the market until it
was practically too late.  MACS and the industry OWNED EPA under
Bush senior.  Klinton was more interested in getting his woody
scrubbed than he was undoing the Bush damage, though EPA did back
off a bit.

Flammables are gaining widespread acceptance in Europe, even in
household refrigerators.  More rational minds, minds not paid for,
govern there.   They realize that the couple of ounces of flammable
refrigerant just doesn't matter safety-wise.

One other thing to keep in mind is that an aerosol of R-12 and oil
or R-134a and oil as would be formed with a sudden system breach, is
also flammable and explosive.  George did a stunning video tape
(after getting EPA permission to vent some R-12!) showing a huge jet
of flame coming from a venting charging cylinder containing a normal
automotive R-12/mineral oil mix.

Once barrier hoses are fitted (propane goes right through
non-barrier-hoses), the standard propane/isobutane mix works
indistinguishably from from R-12.  No need to buy the hyped stuff -
one can easily mix their own using isobutane camp stove fuel and
propane torch fuel (don't ask me for instructions - search the web
for instructions!)  Don't use gas grill gas - it's usually saturated
with water.

Not a flame.  Just thought some first hand info from someone who's
been in the trenches would be useful to the discussion.

John