Date: Fri, 28 May 2004 15:28:49 -0700
Reply-To: Robert Fisher <refisher@MCHSI.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Robert Fisher <refisher@MCHSI.COM>
Subject: Re: A/C charging and maintenance...
Content-Type: text/plain; charset="iso-8859-1"
*snip*
> instead of using R134, use HC-12a, or similar propane derivative freons.
From the EPA website:
1.. What is the legal status of hydrocarbon refrigerants such as HC-12aŽ
and DURACOOLŽ?
It has been illegal since July 13, 1995 to replace CFC-12 with the HC-12aŽ
formulation that was submitted for SNAP review in any refrigeration or A/C
application other than industrial process refrigeration. The same
prohibition for OZ-12Ž took effect on April 18, 1994. Because DURACOOL 12aŽ
has the same chemical composition as the HC-12aŽ formulation that was
submitted for SNAP review (i.e., Hydrocarbon Blend B), DURACOOL 12aŽ is also
subject to the same restrictions.
HC-12aŽ, as reformulated to meet DOT requirements, is not the same as
Hydrocarbon Blend B and has not been submitted for SNAP review. OZ
Technology is therefore prohibited from marketing this blend as a substitute
for any ozone-depleting substance. In addition, any use of this blend as a
substitute for CFC-12 or any other ozone-depleting chemical, in industrial
process refrigeration or any other refrigeration or A/C end use, is
prohibited under the Clean Air Act.
Since HC-12aŽ, as submitted for SNAP review, is chemically different from
HC-12aŽ, as reformulated to meet DOT requirements, and since it has a
different legal status under the Clean Air Act, users of any substance
marketed as HC-12aŽ should be aware of which HC-12aŽ they have purchased.
Note that the Clean Air Act does not regulate the use of any of these
hydrocarbon refrigerants when they are used as replacements for
non-ozone-depleting chemicals such as HFC-134a. However, many states
prohibit using flammable refrigerants in motor vehicles, regardless of which
original refrigerant was used in the vehicle.
2.. May hydrocarbon refrigerants be used to replace CFC-12, commonly
referred to as "FreonŽ ," in cars?
No. It is illegal to use hydrocarbon refrigerants like HC-12aŽ and
DURACOOL 12aŽ as substitutes for CFC-12 in automobile or truck air
conditioning under any circumstances.
> These are sold under various names, such as DuraCool, Freeze 12, etc.>
Duracool: see above.
Read the whole thing at:
http://www.epa.gov/ozone/snap/refrigerants/hc-12a.html
It goes on to state the conditions under which you _can_ use hydrocarbon
refrigerants in motor vehicles, and which states prohibit their use
entirely, etc. A little more on that below.
Freeze 12:
This is not considered a hydrocarbon refrigerant. It is manufactured by the
same people that make 'Castrol' products, among other things. It is a
mixture of 80% HFC-134a and 20% HCFC-142b. It is considered 'acceptable' by
the EPA. (EPA only lists two 'approved' automotive refrigerants, R-12 &
R(HFC)-134a; the rest are either 'acceptable' [
http://www.epa.gov/Ozone/snap/refrigerants/macssubs.html ] or
'non-acceptable'). While it is technically flammable, due to the HCFC-142b
component, one analysis I read stated that it would not ignite until it
reached a temperature of around 900 degrees farenheit, thereabouts. I
couldn't find that link again, tho, but the author basically made the point
that if your refrigerant reached 900 degrees, you had far worse problems
long before that happened.
Freezone: Basically the same thing as Freeze 12, but 79% HFC-134a and 19%
HCFC-142b with 2% lubricant added, made by a different manufacturer.
Both manufacturers claim this combination resists 'fracturization' or
splitting of the components, which is apparently most important if you
develop a slow leak. Again, I couldn't readily find the information on the
lubricant (it's been a while since I looked into all this), but I think it
was ester- if it is, folks with Sanden compressors might want to avoid it.
As in:
Both of these are supposed to be compatible with both ester and pag oil,
however all the material I've seen on the Sanden 709 recommends/requires pag
oil with R-134a based applications.
> They give as good a cooling effect as the older R12, but have a much
> lesser head pressure (and hence on our Vanagons the compressor has to
> work less hard).
This appears to be the case, however you're supposed to use 90% of the
vehicle's R-12 capacity. Cooling at the vents is widely reported to be
comparable.
> In the US, to legally use them you must first convert the vehicle to
> R134 oils and fittings and then you must properly label your vehicle.
Some more from the EPA:
Is it legal to replace HFC-134a in a motor vehicle with hydrocarbon
refrigerants such as DURACOOL 12aŽ and HC-12aŽ?
In certain circumstances, the replacement of HFC-134a in a motor vehicle
with hydrocarbon refrigerants might be permitted. At a minimum, in order to
avoid violating the Clean Air Act, the motor vehicle A/C system must have
either been originally designed for use with HFC-134a refrigerant, or must
have been previously retrofitted from CFC-12 to HFC-134a refrigerant, AND no
sham retrofit must have occurred to convert the system to the hydrocarbon
refrigerant. In order to avoid violating other laws, the replacement of the
refrigerant must not violate any state or local prohibition on the use of
flammable refrigerants in motor vehicle A/C systems.
The following 18 states ban the use of flammable refrigerants such as
HC-12aŽ and DURACOOL 12aŽ in motor vehicle air conditioning, regardless of
the original refrigerant: Arkansas, Arizona, Connecticut, Florida, Idaho,
Indiana, Iowa, Kansas, Louisiana, Maryland, North Dakota, Oklahoma, Texas,
Utah, Virginia, Wisconsin, Washington, and the District of Columbia.
*snip*
Btw, I've read on several boards where people used various refrigerants as
'drop-ins', that is, they used them to top off an R-12 system that still had
R-12 in it. According to the EPA, this is illegal, period.
There are a lot of arguments in boards online about the advisability of
having pressurized propane (or other hydrocarbon coolants) in your engine
compartment. The cons say that's keeping a bomb next to your engine and
begging for a fire/explosion, while the pros say you already have that
situation with your vehicle fuel, particularly if you have fuel injection.
It also brings to mind the numerous folks that have propane bottles in their
RVs and campers (i.e. Westys) I see it as an issue of personal common sense;
given the choice, I go with the 'non-flammable' compounds- just avoids the
other issues altogether. They're also easier to obtain and maintain.
Enforcement of the laws seems to be minimal or non-existent, particularly on
the user end; I really doubt you'll ever find the Refrigerant Police kicking
in your door if you go with the 'non-acceptable' stuff, but I figure it's
always wise to at least be aware of the law before you decide to break it,
if that's the case. Otherwise, it's a personal ethical question
(safety/environment, etc.).
Food for thought and awareness, anyway.
Cya,
Robert
'87 GL
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