what is the best blend for low temp

[zolar1]

So no one can answer my questions?

Can I just use straight R290 in both domestic refrigerators and window A/C's?

Maybe that will get things cold....?

[herefishy]

Zolar... to be straight with you, you need to contact the manufacturer of the equipment that you are servicing. Typically the manufacturers test their machines with some of the interim or replacement refrigerants.

For instance, in employing R-409A int some medium temperature systems (which then would not work), I contacted the manufacturer (Tecumseh) and they told me R-409A won't work in their condensing units, because they do not have enough condenser coil.

So, in regard to your frustration there simply is no simple answer. Contact the manufacturer, or experiment a little yourself.

The manufacturer may say, " If you put R290 in it, your in for trouble, we recommend using refrigerant x because we tested it and found that ..blah, blah, blah".

[zolar1]

Thank you herefishy for your insight. Much appreciated.

[superheat]

Zolar, I posted this before but it did not take.
I pressurize the system with 5 psi N2 and drill a 1/8 hole in the corner of the compressor. The hole will not be full size on the inside surface of the compressor if you stop as soon as the oil start to come out. I tilt the compressor to drain more oil and measure the amount of oil removed. I tilt the compressor back away from the hole, file the paint away from the hole. N2 flowing the whole time. I leave a line open when I silversolder the hole shut. It takes about 1/2 minute to solder the hole shut. Cool the compressor with a wet rag. Pull a vacuum and recharge with AB oil. First one I did was over 4 years ago and it is still running. I think if drain enough oil and tilt the compressor back, the oil will not get hot enough to decompose.
SUVA data shows 409 does not mix very well with MO below 0 degrees, 15 degree evap. Data from some of GHG's early brochure say the same thing near as I can remember. His early data also says 414 is a very good top-off ***** for R12. EPA rules prevent him from publishing that info anymore.
I think refrigerator manufacturers are not doing anybody any favors using 134a. I worked for a refrigerator manufacturer in '95, but they never listen to engineers anyway. My freezer and refrigerator at home both have 401B.
I do not do any domestic work unless I have to. You know, close family and good friends.
Glad to see somebody talking about mixing their own *****. I have had a couple of tightwades refuse to pay me to recover and recharge after a leak has fractionized the *****.
I think HotShot is the worst ***** I have used. 409 is not much better. Most of my systems have the compressor on the bottom and evap on top. For medium temp, I have used 401 without an oil change. The oil will flow down hill in the off cycle. If the evap drains off the bottom, I have seen no problems.

[zolar1]

I would love to be able to mix my own concoctions of refrigerant, but the epa says it's illegal to mix refrigerants. What I don't understand is how manufacturers can make the 400 series and not be breaking the law. Those are mixed refrigerants, aren't they? (yes they are). Then how come WE can't mix them? (as long as the item is properly labeled, then what's the problem?)

About drilling holes in a compressor - if I had the compressor already removed, I could just dump the old oil out and pour the new oil in. I was looking for a way to do it without removing the compressor, then find a suitable refrigerant.

You recommend 409a, but you in turn state you use 401b for your friends. I'm getting mixed messages here. Why would you use 401b for your friends, and 409a for everyone else?

Will GHG's 406a be adequate (I have 50 pounds of the stuff)

About using 414b to top off R12 systems - I know at least 2 tech's that do that regularly. I know of one that tops off with 401a.

[ghg]

EPA Rules.

On "mixing refrigerants", the last I remember the
prohibition on mixing was just for section 609,
MVAC.. MACS (www.macsw.org) [Ward Atkinson]
was the real force and lobbying behind all this.
He wanted just 134a and PAG oil for cars..
Used to make the excuse "we can have only 1 ref-
rigerant" since service techs would get confused
with more".. He did not mention that was OK to
have no less than 40+ brands of PAG oil at the
time, many of them non interchangable. Hippocrit.

I havent checked recently, but it used to still be
legal to mix and topoff with different refrig-
erants under part 608 (HVAC and stationary).

If you declare it "R & D", pretty much anything
goes, even venting. How do you do a flammability
test without venting?

I gave a paper on R406A at the 1992 Purdue
Compressor conference. Had all kinds of
videos of refrigerants venting into fires, etc.
Room was packed, about 1/3 of them were EPA.

I mentioned that the EPA rules cover
(not exact quote but close), "The installation,
servicing, repair, and disposal of appliances
containing ozone depleting substances ..."

R&D is not one of these. AN EPA person popped
up (may have been Cynthia Gage) and said that
was correct. As the videos showed venting, etc,
some of the room chucked, but nobody in the EPA
gave me any crap or venting fines...

R-290. Back in 1990 (before SNAP was in force)
I told Bill Hardaway that I discovered that
the pressure-temp curve of Propane seem to almost
exactly match that of R-22. He charged it into
2 or 3 window A/C units, and as far as I know
they are still running OK.. Same peformance.

Dont put R290 into things made for R12.
Pressures will be way too high. 60/40
blend of propane/isobutane pretty well matches
R12.. that was GHG-X1 back in 1990.

As long as you label it "R&D", and I would assume
keep a log book and have a good excuse to
be doing research on.. You can pretty much mix up
anything that you want to.

Oil miscibility points, where 150 SUS mineral
oil separates from the refrigerant that I
have determined for various refrigerants..
Depending on system geometry and gas velocities,
mineral oil may still return colder than the
"two phase" (where the oil and refrigerant
separate). The oil will always return at or
above the two phase temp.

refrigerant two phase with 150 sus min oil
R12 below -40F
R406A below -40F
R414A -10F
R414b (hotshot) +18F
R409A (FX56) +32F
Freeze12 was two phase at room temp 70F

--ghg

[zolar1]

As usual, my hero George came to my rescue!
Thank you!

So, in my quest to satisfy the 'My frig won't freeze my ice cream', I can legally experiment with refrigerants, and NOT have to need a special license or anything?

Since most of my experimentation would be approximately 4 ounces or less, the environmental inpact would be minimal.
Also, to destroy mixed refrigerants, doesn't the recycling places burn the mixture to catalize the chlorine or just heat it and add oxygen to the mixture?

Just a thought....how would the addition of ethylene glycol, in a very small quantity, affect performance? The stuff is rather slippery, lubricates automotive water pumps, and usually contains silicon silycate to prevent corrosion. Maybe that would protect evaporators or be a suitable substitute for compressor oil?

The reapplication of existing technologies for the purpose of producing a better product could make life better for us all.

[superheat]

Reread Zolar.
I do not like 409. It has higher discharge temps. And it seems like it hunts alot more often than 401. I hate the feeling I get when I leave a system where I have replaced a compressor for the 2nd time in a few years and the dang thing will not stop hunting.
I work mostly on small sommercial refrigeration. The condensing unit will slide out and move around easily. That idea would not be as convienent on a domestic refrigerator.

[Andy]

Hi, ghg
Just a thought, if I was building a heat pump set-up to heat a house, would propane be an appliciable refrigerant. I have this idea floating around my head where I could use a wind powered generator to charge batteries, this D/C power could be then fed to one of thess 12v to 240v A/C inverters that are common nowadays. The beauty of using a heat pump would be I could get 3-4Kw for every Kw generated (less losses ofcourse).
Anybody else interested in anything similar?
Regards. Andy.

[ghg]

etyhlene glycol is very moisture grabbing
and water based.. The dreaded "PAG" oil
which fails many a new car R-134a system
(due to moisture -> acids) is

Polyalkleneglycol, very similar...

Since it is water based, I think PAG
compressor oil may do a better job as
"water pump lubricant" when dumped into
the radiator instead of the A/C system.

---
Andy,

Good idea. Propane, R-290, if it is "dry"
is a direct match for R22. Get a moisture
indicator site glass from "Prof Sporlan"
(They make the best ones), and change dryers
until it goes green. Also, I would use
SUS 300 mineral oil, instead of the usual
SUS 150, since propane dissolves so well
in mineral, it will thin it out some.
In Ireland, you have no US EPA to ban
R-290 there as in the US.

On the rest of your system. Hope you have
a windy area, or a big Jake 20KW generator.
In general, my opinion is that electricity
is too valuable (when made from RE like wind,
solar) to use for heating, even with a heatpump.

You may need to put a "hard start" kit
on the compressor and/or crock up some
method of starting it unloaded (solenoid to
connect discharge to suction) for starting.
The Inverter better by a duesy, since it
will be a bitch to start the compressor


best of luck.
--ghg

[Andy]

Hi, ghg
thankyou for posting back. I have started my heat pump project, on a small scale anyway. I am going to heat my office with small heat pump capable of an output of 1.2KW. The heat exchangers are made and the compressor fitted to a base. I have opted to fit a R12 compressor hopefully I am going to run it on Butane, should be a close match. It will be a week or two befrore I have time to do much else to the heat pump, I will posta picture sometime.
Regards. Andy.

[ghg]

Using N-butane with an R12 compressor will
only run at 1/4 capacity of R12, due
to lower pressures and massflow.

60/40 blend of propane/isobutane by weight
is much closer to replacing R-12.

N-butane boils at +31F
Isobutane boils at +10F
Propane boils at -44F
R12 boils at -21F

sorry bout the non metric non celcius units.
--ghg

[Andy]

Hi, ghg
Looks like I will have to borrow a charging cylinder if I hope to acheive a mix to replace R12. Also the oil thing, I think I will change out the oil for a grade with a slightly higher viscosity.
Here in the UK the main source information on HC refrigerants is a body called ACRIB, they have a guide that is down-loadable from their web site, that is what I am using for a guide.
Thinking again I might try my little compressor on Propane first, if the current seems excessive I can recover a percentage and add butane as replacement.
Thanks for the info.
Regards. Andy

[ghg]

try looking up calor gas in the uk.
I heard they sell premixed HC gasses
for refrigerant use..The may have
something close to 60/40 propane/isobutane
already made up, clean and dry.
--ghg

[zolar1]

I looked all over and can't find any kind of 'BAN' made by the epa on hydrocarbon refrigerants. Where is the list of banned refrigerants please.

Also, regarding a 'ban' on refrigerants - I'm sure there's a loophole somewhere since a company in Arizona is making and selling the stuff for use in auto's, central a/c's and ice makers in the US.

[zolar1]

Why mirror R12 anyway?

Zeotropes are more efficient aren't they?

The 60/40 blend of propane/isobutane mirrors R12.....would a 70/30 mix be colder?

How would a 50/50 mix of R22 and R290 fair?

If the EPA was that concerned about the environment, wouldn't it make sense to explore all possibilities concerning refrigerant replacements instead of banning potential replacements?

The data I read about R290 indicates that it ignites at a temperature almost 2 times that of the propane you use in your domestic gas grill. If the cheap propane (ignites about 800+ deg F) is considered safe for the typical user, why wouldn't the safer R290 Propane (ignites approximately 1683 deg F) be suitable??

It sounds like somebody has a politician in their back pocket.........

[zolar1]

George's R406A isn't rated A1/A1, and in fact is listed in the Modern Refrigeration and Air Conditioning book by Althouse as being flammable. Page 352

And yet, the R406a is allowed to be used.

I thinks we need to take up a collection for george to fix this greedy epa problem..............

[Andy]

Hi, ghg
I could go buy a much nicer prduct from Calors Care range, but where's the fun in that. When I have the heat pump system balanced with the heat exchangers at their correct dimentions (near enough) I will think about putting my hand in my pocket.
Besides Calor will not sell me gas unless I go do their training course and register with them, I will have to think of an excuse why an industrial company sends me on a course aimed at the domestic market. Also by completing the course I would be able to down load the design info off their site.
Regards. Andy.

[Richard]

I would imagine 134a with mineral oil would cause poor oil return because it does not mix. causing oil to logg in the evaporator and could cause premature compressor failiure because of lack of oil.

R401a is recommended for low tempreture application replacement for R12 (Suva MP66)

[ghg]

Originally posted by zolar1
George's R406A isn't rated A1/A1, and in fact is listed in the Modern Refrigeration and Air Conditioning book by Althouse as being flammable. Page 352

And yet, the R406a is allowed to be used.

R406A was rated A1/A2 (now A2)
This means nonflammable as formulated then
lower flammability group after worst case
fractionation. certain quantities of A2
refrigerants are permitted in many uses.

Propane is "A3" (explosive), and R406A
"weak" flammability is so miniscule, as
it isnt noticed during normal service
(brazing) operations. Flammabilities have
a wide "range". More info on www.autofrost.com
The product liability insurance company for
People's Welding Supply (R406A mfgr) is convinced
that the "miniscule" flammability is not an issue.

For those (big boys) who stir up all these
"miniscule" flammability issues to keep the
little guys out of the "club", there is R414A
(sister refrigerant to R406A) which is classified
as A1/A1. R414A caused a big furor in ASHRAE
circa 1995. AFter it passed the UL2185 flam.
test, worst fractination at 100C, it was
discovered that R500, HP80, MP39, etc
(R402, R401), did not "pass" anymore. Ammonia
went from B2 to B3 (in the same flammability
group as propane). In trying to stop R414A,
the big boys just lost their UL on a bunch
of refrigerants for a couple of years while
ASHRAE and UL hemmed and hawwed on what to do
about it. They eventually lowered the flam
test for wff from 100C to 60C, and everybody
else, except for 414A had to retest, so the
big boys could get back in again to their own game.

There is a current furor raging in Europe, where
the HC makers are fighting with the HFC makers
over the HFC makers setting the safety standards
to exclude the HC makers. HFCs have a big global
warming potential where the HCs have no global
warming.. should be an interesting fight.
--ghg

[ghg]

Originally posted by zolar1


The data I read about R290 indicates that it ignites at a temperature almost 2 times that of the propane you use in your domestic gas grill. If the cheap propane (ignites about 800+ deg F) is considered safe for the typical user, why wouldn't the safer R290 Propane (ignites approximately 1683 deg F) be suitable??

It sounds like somebody has a politician in their back pocket.........

Same propane, different Bull****..

This is from the makers of OZ-12 and HC-12a
(propane/isobutane) refrigerant.. They
dont understand ignition energy.

One tiny spark, and propane (which is R290)
goes boom.. if mixed with air 2-8% v/v.

-----

Zolar1, yes 70/30 is colder than 60/40..

what are you trying to do? coldest final
temp or fastest "pulldown" to some temp?

Checking for a leaking door gasket would
probably eliminate lots of this anyway.

For fastest pulldown, R406A, R414A or B
will be about the fastest pulldown.

To be the coldest, Pure propane (R290)
or colder (R1270, propylene), another
10F colder would do it, but you will overload
the compressor and condenser during the
pulldown.. You could try an EPR (evaporator
pressure regulator) type device, so the
compressor doesnt overload during startup
and early pulldown. This type of device
limits the max suction pressure a compressor
sees..to limit the load and let you
run a colder refrigerant.. even R502 in
an R12 system
--ghg

[superheat]

I was talking a friend of mine that teaches automotive repair about 414. He says ASE recommends against using it in cars because of the flamability. I thought it was approved for automotive use.

[ghg]

Maybe it is flammable to ASE's wallet.

R414A has passed the UL2185 Test under
stricter conditions than almost any
other refrigerant (wff at 100C). UL2185 had
to be backed off to (wff at 60C), just so
R-500, MP30 (R401X), R-402A, etc, could
get their UL ratings back again. R414A
got classified ASHRAE A1/A1, then to A1
(same as R22 for flammability).

We have had a couple of car fires in
cars with R406A, similar to R414A, but
ASHRAE A1/A2 (weakly flammable at worst
fractionation), but 406A flammabiltiy is so
"weak", it cannot be noticed during
normal field work (brazing, etc). The car fires
started from leaking gasoline in the fuel
system, then burned thru a rubber *****
A/C hose, dumping the R406A charge, which
put the fire out and saved the car.

Ask your friend if he knows that R134a becomes
flammable/explosive if mixed with air at above
5 PSIG? (that is why you are not supposed
to pressurize with shop air to leak test -
us nitrogen instead). All HCFCs and HFCs
(R22, R134a, etc, incl R406A/R414A) will
become flammable if mixed with air under
pressure. R414A and R22 need large amounts
of air (about 50%) and more pressure like
40-50 PSIG to become flammable in air/
refrigerant mixtures.. R134a only takes
5PSIG to become flammable in air under pressure.

All refrigerants burn when mixed with oil,
especially if a liquid line breaks and expells
a "fog" of oil. This oil fog can be as
explosive as a propane cloud.

I carry a jug of R414A for use as an emergency
fire extinguisher.
--ghg

[zolar1]

So wehat you're telling me is that the HC makers are spreading bogus information about their product as being safe and 'approved'?

And George's R406a is not safe, contrary to Althouse's book?

Too bad the industry won't do it the K.I.S.S way.......

K.I.S.S. = Keep It Simple Silly

If propane is that hazardous, then why is it allowed in Propane refrigerators? Or home grills?

Either it's safe or it's not. This is getting confusing to say the least.

When CAN you use R290 as a refrigerant???

[zolar1]

wouldn't a TEV be better than an EPR?

I'm trying to eliminate the "my ice cream won't freeze' or 'my beer isn't as cold as it should be' complaints.

I also get the ' my A/C isn't blowing cold....can you come out and put in some ''freezone'' for me?'

People here want a 100,000 btu window air conditioner so that they can see their breath in the summertime in 9 huge rooms....and yet those same people complain their apartment is too cold in the wintertime and it's 95 deg F!

I wonder if I could get my customers to sign a liability waiver for me to use R290 or propolene? Would I still be liable if there was a fire or injury?

PS Ice cream hardens around -20 to -25 deg F and is rock hard at -30

[zolar1]

Here is a link for more information on HC refrigerants.
http://ctan.unsw.edu.au/pub/archive/HC/HC.html

[zolar1]

George,

Let's assume I want to use R404a (R502 substitute).

Since the 404a uses the same POE oil as 134a, couldn't I just use the 404a instead of the 134a?

Or how about a blend of the 2?

How is R409a different than R404a?

[ghg]

Zolar1,

Yes, you could put some R-404A in a R-134a system, and the
ester oil would work.. BUT.. R404A is almost twice the pressure
of R134a, so serious compressor overload could result...
--ghg

[cpt. cascade]

copeland refuses to honor warranty on ultra low temp aplications because we run our compresors at such high compression ratio . useing 134a blended with 404a runs around 5psi suction 175psi head, maintaining -42c under a load. Keep in mind this is a flooded evaporator (no superheat) cap tube system. I use this blend for alot of aplications other than cascade systems and i love it. The way i was taught the 134a helps to reduse head pressure and also as a glide. 404a runs something like 240 head in this aplication, by itself, so odviously it does its job. i love this blend and on almost all my 404a aplications i add a little 134a to keep my head pressure down.


maybe you could tell me some reasons why this blend is bad?

[cpt. cascade]

double post please delete. sorry

[zolar1]

Rog,

Believe it or not, the low temp frig compressor on the soda pop machine is still working today.

I believe it may be because the partictular machine is located in a normally cool environment.

I did just have to work on it, but the problem was a crack in the line due to the line vibrating against something inside the box.

Of course, I wouldn't dream now of using that setup unless the customer was so darned cheap that there was no other way.

ALSO - George, I got lucky the other day. A frig guy just moved here and was hard up for $$$. He sold me his R414A (partially used, but total bottle weight = 23 pounds, and pressure was correct).

Can't wait to try it.

I still have about 1/2 bottle of R406A left. I'll have to get some more soon - :-)

[adacus1]

Quick safety point.

When the system is charged and no air is in the system, 100% it is non flammable - Oxygen needed to burn it. So along comes the engineer/technician and lo the system is cracked and 'all' the refrigerant has leaked from the system but it hasn't. At this point you will be at the low end of the flammability range say 2-4% propane plus AIR (21% Oxygen) and it only needs to be brazed up. So there you are torch in hand ready to braze - A BOMB. As you touch the torch flame towards the crack having cleaned it all nice and shiny - everything disintegrates into a pile of flying shards. The system would have to be completely nitrogen purged to remove all traces of Propane / butane etc before you could hot work it. Would the engineer/technician even know there was an HC refrigerant charged by the last tech?

Central air conditioner with HC refrigerant where is the evaporator right above the gas fired central heating boiler.

Or a Container vessel loaded with 2000 reefer containers with 10lbs of HC refrigerant totalling 20,000lbs of propane

[dude]

Originally posted by zolar1
About drilling a hole in a compressor to drain the oil out....

How do you seal the hole back up? Braze a screw into the hole? Or a nail? Did you have to use oxy-acetylene torch to reseal it?

How would using R134a in a mineral oil or AB oil domestic refrigerator fair? IE would the compressor overheat or what?

Just a note: I recently replaced a soda vending machine compressor (Locked Rotor of 31) with a refrigerator compressor (Locked Rotor 25) and added one of my home made heat exchangers to it. The head pressure was about 175 psig and suction pressure was 20 psig, using straight R414b.
Amp draw on the compressor was 4 amps @ 120VAC 60Hz

By the way, domestic refrigerators here in the US RARELY if ever are rated in Horsepower. Nearly all are rated in Locked Rotor.
Is there a conversion chart somewhere?

Locked rotor amp means nothing more than how many amperes the motor draws at rated voltage with the rotor locked up. It is useful for deciding the size of a circuit protection device.

You can say its the starting amp or amp it draws when you cycle the compressor too soon and rotor locks up.

For the same capacity compressor, ones with power factor correction capacitor or hard start kit will have a lower LRA.

[shogun7]

Zolar1
that's not very nice now ..is it?
a response to your post about the guy who was using mineral oil with 134a
dixi

[abbasi]

R 417A or Isceon 59


u can mail me


got_ya@excite.com or see attachment


for research paper i presented for this refrigerant in


International HVACR conference

[ghg]

Abbasi,
good posting. I picked the attachments ok.. and looked them
over quickly. Will read them in next couple of days and
let you know more.

This is a quick answer for now. I have a jug of R-417A for testing,
but havent opened it yet. From what I hear from others, R-417A
has a capacity loss of 10-30% compared to R-22. This is probably
in cap tube systems I would bet. BTW, Isceon59 and R417A are
the same thing.

There is another blend, called RS-44, which is pretty much R-417A
that has more R-125 in it and pressures/capacity matches R-22
better.

Both R-417A and RS-44 will prob carry enough mineral oil for
"normal" operaion, but may not carry enough mineral in long
suction line runs or unloaded operation due to lower suction
gas velocities. I developed a 5 gas blend that pretty much
tracks RS-44, but carries mineral oil at slightly slower suction
gas velocities than does R-22. Both RS-44 and R-417A quit
carrying mineral oil at about 1/2 full load suction gas vel.

Here in the US, it is Puron, Puron, Puron (R-410A)..
The "Business Friendly" refrigerant. Need to change out
your R-22 equipment for New Due to higher pressures.
R-410A wont work in mineral, so POE is needed, which is not
stable, so you get to keep replacing the equipment every
4-5 years instead of 25 years with R-22/mineral.

I will be presenting my blend at the Purdue Compressor
conf (and intl refrig conf) the week of July 12, 2004.
I doubt if we ever commerialize it, since it is not "business
friendly" since it uses MO and doesnt require POE.

You are in Pakistan, just use R-290. cheap, stable,
direct match for 22, uses MO, and no moisture problems.
--ghg

[t-bone]

Wow. Some great info on low temp replacements for r-12. I have been using r-416a for four years on refrigerators, freezers, walk in coolers. and mobile ac units. It has the lowest head pressures of anything else I have used. 414 ,409 and others such as freeze 12 for mobile units have head pressures that are 10 to 15 psig higher than r-12 originally had. Compressors failures and leaks seemed to be worse when we were using 414 and 409. 416A works well but the pressures won't be quite what r12 was. It will not get quite as cold as 12 in some systems.

But I am open to new ideas if its affordable.

[bashirac]

Hello everybody