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R-406a?
...unabashedly pilfered from another listserver. Do any of you have any
experience with this stuff? Lots of info in here that's way over MY head.
My AC's been out for a couple of years, but with some other work coming up
I'm considering fixing it at the same time. All this conversion stuff
seems pretty expensive compared to some of the R12 "replacements". I just
don't know enough to separate the facts from the infighting.... --G.
'86 5ks by the Hudson (and all those other cars, trucks, bikes, and tractors)
--REFERENCE--------------------------------------------------------------------
Date: Fri, 28 Jun 1996 14:13:15 -0400
From: James Butler <butler@elvis.comm.mot.com>
Subject: More info on "FR-12", a claimed R-12 replacement
I got this info on FR-12 from rec.autos.tech and George Goble gave the
following reply. This was the only snippit of the thread that was available on
our NNTP server, unfortunately.
It appears that FR-12 could be much better as a replacement
refrigerant.
George is still championing his GHG-12 a.k.a. R-406a, which, if it's now
publically available, sounds like the way to go.
Me? I still have 27# of R-12 left in a 30# can that I bought a
couple of
years back. There's a big volume of ozone up there with my name on it,
yes-sir-ee.
Jim
RDJ wrote:
>
> George Goble (ghg@worlidserver.com) wrote a very lengthy reply to "GNC"
> who asked about one-for-one FR-12 for R-12 replacement. I'm sticking my
> two cents in here because GNC may have seen my "information-only" posting
> about InterCool Energy Corp. FRIGC FR-12.
>
> George, your knowlege of there systems seems extensive and, to a layman
> like me, confusing. My interest in the FR-12 (and, I thought, others
> would be interested too) was finding a lower-cost alternative to having
> the A/C system virtually replaced in my two vehicles. Being one of the
> many who has seen their income effectively (if not actually) reduced,
> saving some money is always attractive. My questions for your follow-up:
>
> You (George) said "Manu...published lit and REFPROP simulation show the
> pressure temperature curves to be too low...." The spec sheet from
> InterCool shows a graph with a virtually identical curve for FR-12 and
> R-12. I don't understand your reference.
>
The spec sheet I saw, used 0-500 PSIG scale on the graph.. so at 32F, the
difference between 20 PSIG and 30 PSIG was the thickness of the line..
Looking carefully, showed the 32F pressure to be around 20 PSIG instead
of around 28 PSIG.. Evaporator pressures are a big deal..
> Also, you mentioned "R-12 boils around -21F...." Per the Spec Data Sheet
> (required by OSHA), the FR-12 boiling point is -24.2 degrees Centigrade.
> The spec sheet provided by InterCool shows a minimum ("Bubble Point" ??)
> of -12.7 deg *F* and a maximum ("Dew Point") of -7.7 deg *F* -- I must
> admit I have difficulty correlating these figures. Help?
-24.2 degrees C is about -12 degrees F, or the "bubble point" of FR-12.
The "dew point" is -7.7 F.. the average being around -10F. The boiling point
for R-12 is -21F .. so from this you can see that (in layman's terms) that
R-12 is going to be about 10 degrees colder than FR-12. R-406A and GHG-X4
refrigerants have bubble points of around -26F and dewpoints around -10F
and will deliver much colder air, better than R-12 almost all the time.
R-406A/GHG-X4 (AutoFrost) also contain 4% isobutane (and R-142b) to provide
excellant oil return to the compressor..One does not have to add unstable POE
oil to make them work.
> The information provided by InterCool relates to the suitability of FR-12
> as a replacement for R-12 without substantial system modification. You
> seem to keep making comparisons to R-134a and using *that* is what I'm
> trying to avoid. You mention "R-12 systems use mineral oil..." and that
> mineral oil is *not* miscible in R-134a (which is 59% of the FR-12, by
> weight). Quoting from the InterCool spec sheet: "While R-134a is
> incompatible with mineral oil, FRIGC FR-12s direct compatibility
> eliminates the need to change lubricants." I must admit some confusion
> when the spec sheet, then, adds "Rather than add the usual ounce or two
> of mineral oil during R-12 charging, you add a similar amount of POE when
> installing FR-12 to enhance system durability." Now *that's* confusing.
The 2% of n-butane they added to return the mineral is not going to work
all the time.. If you have small diameter suction lines, and the compressor
is downhill from the evaporator.. then FRIGC may work.. but pure R-134a
(using R-12's mineral oil) will probably work in this case also.. But if
your compressor is far away and/or uphill from the evaporator and/or larger
diameter suction line (line from evap to compressor, large diameter implies
lower gas velocity), then the oil may "log" (become trapped in) the evaporator
causing the compressor to fail from lack of oil. We have heard reports of
this happening to some that have tried FR-12.
Besides, if FR-12 did return oil ok, then why did Intermagnetics (FR-12 mfgr)
take out a full page AD in the "Air Conditioning, Heating, and Refrigeration
News", around the week of Jan 15, 1996 (I can get the exact date and page
if anyone wants it), and this AD said that POE oil must be added during the
retrofit?? POE oils are unstable compared to mineral oil, and easily break
down into fatty acids and alcohols.. If the POE oil did not break down, it
will cause the FR-12 to return more oil from the evaporator, and probably not
fail the compressor from oil starvation. Since the addition of oil is needed,
FR-12 is not a "drop-in" substitute. Freezone also makes a similar
refrigerant,
made of R-134a (around 80%) and about 20% R-142b.. This also has bad mineral
oil return properties.. so they add some kind to lubricant to the refrigerant.
It's pressures are also too low.. If you have a leaker, and you car needs
recharging, then the constant addition of oil, can cause too much to build up
and cause slugging and broken compressor valves, etc.
> Please understand, George, that I am -- in no way -- being critical of
> your response to "GNC." My hope was that I could call around to local
> service shops and, as a better-informed customer, inquire about whether
> they can recharge my depleted system with FR-12. If, in fact, the FR-12
> provides a less-than-satisfactory (but much less costly) solution to my
> predicament (my A/C doesn't work and it's getting hot and muggy!) than
> the conversion to R-134a.... Well, so be it. But I need to know and,
> George, you sound like the man to help me become informed.
Who said you have to use FRIGC.. there are other alternative refrigerants,
which are drop-ins (no oil change), and which provide better performance
than R-12...
> Any clarifications you can add will be appreciated. Thank you.
>
> Rick
On cycling clutch compressors, the too low pressures (too high of boiling
points) of FR-12 will cause constant cycling off and on of the compressor,
causing clutch failure in 1-2 months (we have reports of this also with
FR-12)..
The low pressure cutout switches need to be changed to correct for this.
With a non-cycling (variable displacement) type of compresser, low capacity
will result (wimpy cooling).. Since FR-12 has completed the EPA snap process,
"EPA fittings" are required by law for them.. If you retrofit to FR-12, and
don't like it.. the fittings dont come off, so you are stuck with it..
You are correct, there is a tremendous amount of misinformation being passed
around about refrigerants, and retrofits, EPA rules (which seem to change
every few days).. Being a refrigerant inventor/mfgr, I have to keep up on all
that.. it is hard for me.. The average person or mechanic, not in the
refrigerant business, will have an even harder time.. much confusion exists..
--ghg
------------------------------
Date: Fri, 28 Jun 1996 14:16:52 -0400
From: Robert Lockhart <lockhart@birch.ee.vt.edu>
Subject: Re: R-12 replacement now available: Pennzoil's "FR-12" Refrigerant
> It appears that an R-12 replacement refrigerant is finally
> available for older systems. I quote from the "New Products" section of
> the July 1996 Car Craft, pg. 128:
>
> "Pennzoil FR-12 Refrigerant:
>
> "Pennzoil Products has become the distributor for FRIGC, FR-12
> refrigerant. Its properties are virtually identical to R-12, also known as
> Freon, the most widely used automotive A/C system refrigerant. However,
> R-12 is now banned by the EPA. FR-12 solves the problem of having to
> undergo costly changes with an R-12 A/C system. It's ready to use with
> only minimal system adaptation and has also been accepted by the EPA. New
> cars now use R-134a, and older R-12 systems can't use R-134a without
> significant alterations. The FR-12 refrigerant is compatible with R-12
> systems. Contact your local auto parts retailer."
>
> Is this just "GHG-12" a.k.a. "R-406a", George Goble's R-12
> replacement conconction? See http://ghg.ecn.purdue.edu/ghg2.html#R-406A,
> George's home page discussion of the matter, as well as
> http://www.worldserver.com/R-406A/. From what I can see, it appears not.
> The only other contender that *I* was aware of (and I'm not an expert) was
> a product that was being worked on (by Dupont?) and was reported in an SAE
> paper that I have in my filing cabinet. From what I remember it wasn't
> *really* a contender because is didn't pass the EPA's flammability
> requirements for such products (again, this is as I remember, so I might be
> slightly mistaken).
>
> Jim
I snagged this bit of news off the net put out by George Goble:
--------------------------begin--------------------------------
From: "George H. Goble" <ghg@worldserver.com>
Newsgroups: rec.autos.tech
Subject: Re: PENNZOIL ADVERTISED FREON-12 REPLACEMENT
Date: Sat, 01 Jun 1996 11:35:46 -0700
Organization: GHG DEV LABS, Inc
Lines: 225
Message-ID: <31B08D82.4A60@worldserver.com>
References: <31AF7048.7E97@erols.com>
Reply-To: ghg@worldserver.com
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GNC wrote:
>
> Anyone have any experience/advise/opinions about Pennzoil's claim that
>they have
> a one-for-one R-12 replacement?
>
> For background, check out: http://www.pennzoil.com/whatsnew/docs/freon.html
>
> What kind of "fittings" need to be changed?
>
> --GNC
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ARTI Refrigerant database lists FR-12 formulation as (by weight)
as R-134a 59%, R-124 39% and n-butane 2%
Manfuacturer's published literature and REFPROP simulations show the
pressure temperature curve to be too low (at evaporator pressures).
This causes a loss in capacity and other problems such as excessive
clutch cycling if low pressure cutout switches are not changed.
R-12 boils around -21F, R-134a around -15F, R-124 at +10F, and n-butane
at +31F. Barring a rare azeotrope formation, how is mixing components
with BPs of -15, +10, +31 going to boil at -21 ??? (all degrees F)
"Efficiency" is defined in terms of energy (work) input vs amount of
heat moved (output). Say a refrigerant only delivers 70% of the cooling
capacity of R-12, but uses only 65% as much "work" input to the compressor,
it can be claimed as more efficient, although its cooling performancy will
be "wimpy".
Due to the low pressure-temperature curve, FR-12 will tend to operate
at around 18-22 PSIG on the evaporator, whereas R-12 runs around 28-32 PSIG.
In many of the common GM (CCOT) A/C systems, there is a low presure
cutoff switch, set around 24 PSIG.. These systems will cycle the compressor
off and on every second or two, causing further reduction in cooling
capacity and wearing out the clutch in a month or two. To save the clutch,
and reduce the capacity loss, a custom low pressure switch will need to be
installed, set about 14 PSIG.
Variable displacement compressor type systems, such as the GM V-5
compressor, have an internal setup to set the suction pressure at
28 PSIG.. These systems will still run FR-12 at 28 PSIG, instead of 21
PSIG, causing around a 40% capacity loss (compared to R-12), and
about 10 degree warmer duct temps in the best cases. To my knowledge,
variable displacement compressors are nearly impossible to have their
suction pressure setpoints modified.
Be careful to read literature and performance claims.. Often they
claim "better performance" than a said vehicle which has been
retrofitted to R-134a. They do not claim better performance to an
R-12 vehicle. Due to the low critical temperature of R-134a,
many cars perform miserably when retrofitted to
R-134a (due to small condensers).
Such refrigerants can still perform poorer than R-12 and easily win
a performace contest with a car retrofitted to R-134a.
The critical temp of a gas is the defined as the temperature
at which at or above, the gas will not turn to a liquid, no matter how
much pressure is put on it. R-134a crit temp is 214F, R-12 is 233F
and R-406A is 236F.
R-12 systems use "mineral oil" for compressor lubrication which
circulates with the refrigerant in the system. Mineral oil is
miscible in R-12, so it returns to the compressor properly.
R-134a is not misicible in mineral oil, therefore it will not
circulate properly (become trapped in the evaporator), and
starve the compressor for oil, causing it to fail. To overcome this
problem, the industry has tried to develop new oils that are
miscible in R-134a such as Polyalkyleneglycol (PAG) and polyolester (POE)
oils. Compared to mineral oil used in R-12 systems, both PAG and POE
oils are unstable, and much more moisture sensitive. These oils
are the crux of the problems with new and retrofit systems, both
automotive and stationary. Major compressor companies are reporting
many problems with oil "gelling", plugging up systems, breakdowns,
even in new systems with R-134a and other HFC refrigerants with
POE or PAG oils. PAG oils are broken down by the chloride coatings
from the inside surfaces of the pipes (created from the R-12, which cannot
be flushed out). POE oils are made from fatty acids and alcohols..
the reaction is sometimes reversible, and the POEs can break down
also. Steel has been shown to be a catalyst for POE breakdown...
POE oil mfgrs have attempted to develop "passivators" to try to slow
down its breakdown from heat and steel. PAG oils are about 100X more
hydroscopic (absorb moisture) than mineral oils, POEs are about
10X more sensitive.
FR-12 components R-134a, and R-124 are not miscible in mineral oil, only
the 2% n-butane. From tests I have done, 5% isobutane (similar to n-butane,
except in boiling point) and 95% R-134a did not produce adequate
oil circulation in an engineering oil misciblity test stand.
Intermagnetics took out a full page AD in the "Air Conditioning, Heating
and Refrigeration NEWS", around Jan 25, 1996, which stated that they
have to add POE oil when converting a system from R-12 to FR-12.
This pretty much confirms the poor misciblity of FR-12 with mineral oil.
CPI engineering, a manufacturer of POE and PAG oils, has told me that
POE oils designed for R-134a, may absorb too much refrigerant when
used with HCFCs, causing them to "thin out" too much to lubricate
properly. The R-124 component of FR-12 is an HCFC.
FR-12, however, does have a relatively high critical temp, so
it would perform well in only one case: Stopped "grid lock"
traffic, on cars with undersized condensers.., as soon as the car
starts moving (more condenser airflow), the capacity will drop
well below that of R-12.
Although, I am trying to be as objective as possible, this posting
is from a competitor of FRIGC. R-406A and GHG-HP are EPA SNAP
"acceptable" for almost all categories of stationary and
transport refrigeration. R-406A, GHG-X4, and GHG-HP
are undergoing EPA SNAP review for the automotive sector at this time.
Their current status is "pending acceptable with use restrictions
(fittings, etc)" and are published in the May 22 Federal Register
Proposed SNAP rule. GHG-X4 (tradenames Autofrost and Chill-it) is legal
to sell and use now for automotive use. According to the EPA OZONE
hotline (1-800-296-1996), GHG-HP and R-406A are also legal to sell and
use for automotive at this time as well.
"EPA retrofit fittings" are required by law on all automotive alternative
refrigerants, even drop-ins, when they finally reach the EPA final
SNAP "acceptable" status. These fittings have unique thread types for
each refrigerant and are supposed to be Permanent and not removable.
They will also be required on the refrigerant cylinder, recovery
equipment, etc, etc.. MACS and the auto industry lobbied this into
law.. their announced reason is to prevent cross-contamination.
Visits to many auto air shops has shown their recycling equipment
to already be "comtaminated" with moisture.. Moisture is a deadly
enemy to all refrigerants (except pure hydrocarbons like propane/butane).
The refrigerant slowly "hydolyzes" and breaks down from the moisture,
and forms acids (hydrochloric and/or hydrofluoric), which eat away
the system from the inside, forming chlorides (sludge) which plug
up the expansion device. The acids often cause the thin aluminum
evaporators to eat thru and fail (a $700 job)..
You ask a technician when he changed the drier in the recycler, and
he usually answers "what drier?".. Most of the vac pumps will not
even move a micron vacuum gauge (needed to asure system is dry)..
and you ask when they changed their vac pump oil (needed for the pump
to deliver a good deep vacuum), and they reply "what pump oil", or
we use ATF (automatic transmission fluid instead of pump oil)..
One can mix all current R-12 alternatives on the market together,
and as long as it is "clean", oil, air, water, acids, etc, removed
by recycling equipment in good condition, they will work OK, provided
enough components (R-12, isobutane) remain to circulate the oil
(a few percent). The auto industry has lobbied in rules/laws
to make mixing refrigerants highly illegal now for the automotive
sector.. with upto a $25,000 fine.. so dont do it in the US..
Why dont they make strong laws also.. so the technicians keep
their recycling equipment properly maintained???
Dytel, that red dye often injected in cars to find leaks... fouls
the moisture indicators on the recycling equipment.. so the
tech cannot tell if the refrigerant is wet or dry.. why dont
they ban that as well?? The owner of the car, may have dumped
in a can of 134a or some R-22 as well.. and contaminate
the refrigerant.. the shop owner has no way of knowing.. with
out expensive refrigerant analyzers.. Best safest bet is to
take all refrigerant removed from vehicles and send it to
a reclaiming center for testing and cleanup and only recharge
with virgin material..
One does not have to have different equipment to recycle oil for
each brand.. Can you imagine one oil recycler for Pennzoil, another
for Mobil, another for Mobil one, etc.. it all goes into the same
pot and goes back for reprocessing. Legit service stations also
do not fill "used" motor oil back into engines...
The Federal Clean Air act of 1990 allows a refrigerant to be sold
in commerce 90 days after it is submitted to the EPA SNAP program,
provided no "show stoppers" are found during this 90 day interval.
The refrigerant next undergoes a 1-2 year examination by the EPA
and associated organizations (like OMB).. and is finally listed as
either acceptable or unacceptable for the intended end use. If listed
as unacceptable, then the sales must stop. From the time of 90 days
after SNAP filing, until the acceptable/unacceptable determination is
made and published in the Federal Register, retrofit fittings are not
required by law, but their use is highly encouraged by the EPA and
the manufacturer and distributors of R-406A, GHG-X4, and GHG-HP.
GHG-HP is not a "drop-in" for R-12, but is a "maximum performance"
refrigerant for south Florida and Texas and other extreme climates.
It can deliver 25-30F duct temperatures (MAX fan, recirc) with
100F ambient temps and high humidities. Installation of a high pressure
cutout switch is mandatory, if not already present.. Some compressors
may need a "defrost timer" installed (non cycling compressors like
the GM-V5).
Like R-134a, and all or almost all of the legal-to-sell or "approved"
automotive alternative refigerants, R-406A, GHG-X4, and GHG-HP leak
a little faster through the older style "nitrile" rubber hoses..
Most American built cars have used "barrier" (nylon liner) hoses
for years (back to 1980 range) and have no major leakage problems.
Foreign cars and "port of entry" add-on A/Cs more often contain
nitrile hoses.. these should be replaced. All replacement hoses today
are of the barrier type and will work. GHG refrigerants (and R-406A)
work with XH-5,6 or 9 desiccants (driers).. R12 systems use XH-5.
New built R-134a systems use XH-7.. Do not use this R-134a only drier
for R-406A or GHG-* refrigerants. If replacing the drier and you
have a choice, get XH-9 dessicant, it holds more water, and works
with everything. Use GHG-* and R-406A only with mineral oil and
alkyl-benzene based oil.. never use POE or PAG oil.. Always charge
product as a liquid (cylinder upright, has a dip-tube)..
For more info, contact Monroe Air Tech, 1-800-424-3836.
or see the homepage in the .sig.
--ghg (Inventor of R-406A, and GHG-X4 R-12 drop-in substitutes)
http://worldserver.com/R-406A
------------------------------end---------------------------
--
Rob Lockhart
Virginia Tech
lock3rd@vt.edu
http://vpihe1.phys.vt.edu/~lockhart