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tony_rich
18-07-2001, 01:07 AM
I tryd frig 12 & 414b I have found some problems with frig 12 on the older systems and on systems not size right it will not pull down to temp has it will with r12 I know the size needs to right but its a hard sell all the custermer knows is it work just fine befor w/ frig 12 there is a diff. of coill temps from 414b .
r-414b has lower coil temp . what do you like to use 414b,mp66,frig12 what works for you and why the one I like is mp66 it looks close to r12 in low temp

zolar1
04-12-2001, 03:14 AM
I like and exclusively use R-414b in my domestic refrigerators and freezers.

There are four reasons:

1) it does not require an oil change
2) it does not require any system modification
3) it is rated at 92btu/lb/hr heat transfer rate (terminology?)
4) R134a is much too hard on the cap tubes and compressors as well as it doesn't seem to want to get cold enough.

I have no problems with 414b unless it becomes fractionated - then it does strange things like make evaporators gurgle.

If you want to make your system colder, then adjust your mixture by substituting 5-10% R22 for an equal amount of the 414b (i.e. if your system takes 8 ounces, then put 6 ozs 414b and 1 oz R22 and top off with the 414b if needed). But try not to overdo it because your head pressure should drastically increase and your compressor could stop working.

My suggestion would be to braze the high and low side tubing together (about 4-6 inches or so long) or install a heat exchanger to help control the higher head pressure.

Home made ones cost about $5 to make, commercially available ones cost about $20 but have a higher efficiency rating. I use 3/4 inch copper tubing for exchanger body, 3/8 inch coper tubing for the low side pass through and 1/4 inch for the high side pass through. You can make them smaller by using 1/2 inch copper tubing (actually it's 5/8" OD) for the exchanger body.

Another item of interest is are you charging the system in the proper manner? Never go by the pound/ounce method but instead go by the low side pressure and ALWAYS charge as a liquid! ! ! The 414b will vaporize in the charging hoses, but that's OK so long as it doesn't vaporize in the DOT 39 bottle.

Applaince @ room temperature (72F)...from a deep vacuum, SLOWLY put in the 414b until you get to 10 psig - if you see frost on the precess stub then stop charging immediately until the frost has disappeared. Start the appliance (pressure will drop to a vacuum), then continue SLOWLY charging at 5 psi, and stopping at 8 psi as soon as you see a pressure increase. Wait for the freezer to drop to about 35F or less, and your gauge pressure should drop about from 8psig to about 3 psig.

Note that some systems will frost at the 5psi mark and usually operate at 2psi or less (those compressors that look like a ball or pumpkin in shape and typically have a drain tray attached to the top of it).

I have managed to get some domestic refrigerator freezer compartments to as low as -10F at the middle settings on the controls by using the 414b & without running for a kazillion hours.

I'm not sure what mp66 is....Do you have a cfc/hcfc/hfc number I can equate to?

k snijders
28-12-2001, 11:44 PM
suva mp66 from du pont = r-401b

zolar1
29-12-2001, 03:09 AM
Did I forget to mention that R414b mirrors R12?

Preston Roy Powell
04-06-2002, 03:57 AM
WE have used R-414b alot in small systems. The other tend to show there refrigeration glide. So keep with R-414b its also close to R-12 so far. M-39 is ok but its got superheat problems and can cause premature compressor problem. I have had test compressor and we have changed them to r-414b also adding heat exchanger will help keep the head down.

herefishy
04-06-2002, 03:32 PM
I like R-409A for low temp. R-416A (frig 12?) for medium temp.

superheat
04-06-2002, 08:46 PM
409 recomends an oil change below 15 degrees. That is above domestic freezer temps. It is just AB oil though. I drill a small hole near the bottom of the compressor. I use a piece of copper tube to prevent the bit from going too deep. Drain at least 1/2 the oil and recharge with AB. Fairly fast and painless. 50/50 - AB/mineral oil is compatable.

Abe
04-06-2002, 10:30 PM
Zolar

Would you mind posting a picture of your home made heat exchanger. Im intrested . Thanks

Abe

zolar1
05-06-2002, 04:50 AM
As soon as I get time, I'll post a pic of my home made heat exchanger.

Since summer is here, I have been rather busy. Please forgive the delay.

Zolar

PS about drilling the hole in the compressor....how are you sealing the hole? Braze it? What about oil degradation and contamination from incinerated oil left over in the compressor?

zolar1
05-06-2002, 04:52 AM
I know of some refrigeration 'ing-in-eers' that put 134a in compressors that use mineral oil without changing the oil.
Any comments?

herefishy
05-06-2002, 09:34 PM
Originally posted by superheat
409 recomends an oil change below 15 degrees.

hmmmm. . . my information syas miscible with all, and denotes no such requirement for lower temps. Who advertises that recommendation?

Dan
06-06-2002, 12:06 AM
We toyed with it in auto a/c units and in an outdoor condensing unit placed below the evaporator. As far as I followed it, the condensing unit below the evaporator worked fine. The auto a/c application worked for about 6 months. But the van had 120,000 miles on it, so it is not certain whether the mineral oil or other factors contributed. We also just added poly oil on top of the mineral charge with varying degrees of success. Not very scientific, but the evidence is that published recommendations are quite conservative. We have avoided experimenting with customers' equipment, of course.

RogGoetsch
06-06-2002, 06:37 AM
I have quit using 409a because of poor performance at high ambient, especially with low temps. Not lubrication problems, but high head. I'm surprised to hear it preferred for low temps in Texas!

Perhaps one reason is that hot weather is so rare here (San Francisco Bay Area) that many units are undersized (low bid!) and many stores not air conditioned.

I have switched to 414b until I hear of something better.

Rog

zolar1
16-06-2002, 02:48 AM
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?

RogGoetsch
16-06-2002, 07:50 AM
Actually, locked rotor amps are not ratings at all.

You MUST refer to the model number and look up the capacity, rating conditions and refrigerant from the mfg's tables, available from any wholesaler and most mfg's websites.

Some model numbers incorporate BTUs and some, horsepower, but without the rating conditions, even those are incomplete.

As far as heat-exchangers are concerned, if you will chart the performance of a system on a pressure-enthalpy diagram, you will discover that the apparent gain from lowering the liquid temperature is completely offset by the rise in temperature of the suction gas.

It may be easier to visualize if you use the box method. Draw a diagram of your system and then draw a box around any component, group of components, or the entire system. Once your system has reached equilibrium (stable operating conditions), energy (electric or heat) crossing the boundary into a box must equal energy leaving the same box. A liquid-to-suction heat exchanger removes some heat energy from the liquid line and sends it back to the compressor without going through the evaporator. There is no net gain in efficiency. The compressor sees the same energy no matter which route it takes. It can even cost efficiency if you locate the HX close to the compressor and heat that would normally have been lost to the environment in a long liquid line ends up as superheat to the compressor instead.

The purpose of the liquid-to-suction heat exchanger is to reduce the potential for flash gas in the liquid line, especially in systems with long vertical rises, reduce the potential for floodback to the compressor and to improve evaporator performance per unit of mass circulated by reducing flash gas in the evaporator.

Rog

zolar1
16-06-2002, 04:19 PM
Just a dumb question here please...........

if you were to take one of your work vehicles contents (ie tools, equipment, supplies) and pack it all into a geo metro, would you have space for all those manuals you refer to? LOL

I need to be able to instantly look at a compressor and instantly know without a doubt if it will work on a refrigerator or whatever. The locked Rotor is the only way to determine this information without having to memorize umteen zillion sets of information.

You see, I take compressors off of one piece of equipment and put them on another piece of equipment. I don't actually need to know what oil is needed since I use R414b.

The bigger the locked rotor rating, the more btu's the compressor can transfer (assume all things being equal) or better yet, the more ***** it can pump & at higher pressures if necessary.

zolar1
16-06-2002, 04:21 PM
I tried an experiment on my own refrigerator. I measured amp draw of my compressor before adding a 10 ton heat exchanger, and again after adding one.

When I go from 3 amps down to 2, what does that tell you? It tells me that by adding the heat exchanger I am saving electricity.
The theory is this: if the compressor has to do less work, you save money. If the suction side pressure is higher because of a heat exchanger, the compressor doesn't have to compress a 5 psi gas to a 175 psi liquid - it gets a 10 psi gas to work with.

Less work = less heat = less wear and tear = more money saved

Just changing the size and shape of the box........

ghg
16-06-2002, 10:26 PM
I am the inventor of several refrigerant blends
to replace R12.

R-406A (called Autofrost in the automotive
market) has been around since Aug 1990.

You will see the same temp/pressure
characteristics as R-414B (ICOR Hotshot),
however the mineral oil return will be
much better in low temp use. R-406A is
miscible in mineral oil down to around -40
or -50F. It is classified by ASHRAE as A1/A2.
It can become "weakly" flammable if most of
it is fractionated (vapor leaked) off. The 10%
remaining liquid can be put in a jar and
lit with a propane torch, and it only has
flames 1-2 inches high and it self extinguishes
after 1 or 2 seconds from breakdown products.

In normal HVAC technician work, such as
unbrazing a line with a small amount of
R406A remaining, one will not even be able
to detect the weak flammability tail, since
it will be masked by the residual oil burning
at the joint. Looks the same as unbrazing
a joint with R12.

If you absolutely have to have an ASHRAE
A1/A1 refrigerant, we also make R-414A, the
sister to R-406A. It is more or less R-406A
with a little R-124 added to suppress the
tiny flammability tail to stop all the
political bitching. R-414A is miscible in
mineral oil down to about -10F. You can use
AB (alkylbenzene, e.g. Zerol) if you need
lower. R-414A passed the tough UL2182
flammability test, worst fractionation
at 100C, which caused R-500, HP80, MP39
(R-401A), etc. to "become" flammable due
to the elevated ignition temp. UL and ASHRAE
hemmed and hawwed a couple of years, and
lowered the wff temp from 100C down to 60C
or such, and everybody else except for R-414A
had to retest, so the big boys could get
their UL back again. Pretty stupid bs, since
the ASHRAE and UL tests do not take into
account the oil in the system. When you count
the oil.. R406A and R414A are pretty much the
same. Even R12 burns with oil in it.

In 1993-1994, we setup ICOR in business to
package bulk R-406A for us in 25lb cylinders.
In 1995 we caught them making extra R-406A
"on the side" outside of the license agreement
(I am the patent holder.. US 5,151,207) and I
had to sue them in federal court to get them
to stop. We also had started on GHG-X4
(which became R-414A) due to all the fuss
the auto industry was making and trying to
"ban" R-406A on the almost nonexistant
flammability. ICOR "stole" their first
"HOTSHOT" which was almost exactly the same
as GHG-X4, from us. Competent legal
counsel determined
that their first "Hotshot" would have infringed
in my patent covering R-406A, and the in
the settlement, ICOR agreed to reformulate
Hotshot (which became R-414B) to have no
more than 1.5% isobutane and no more than
9.5% R142b, both of which are very crucial
to be able to return mineral oil to the compressor.

R-414A and R-406A have 4%
isobutane and 16.5% or more R-142b, hence
their much lower operating temps in mineral
oil. Both work in AB oil as well, but not
required.

Since R-414B is formulated "just outside" my
patent, it is marginal in carrying mineral oil.
It may work in some systems and not in others.
I measured R-414B mineral oil miscibility at
+18F in 150 SUS mineral oil.. which is still
better than FX-56 (R-409A) at +32F in mineral
oil. Dupont is open and upfront on R-401A/B/C
and they state to use AB oil only.

So, R-414B, R-409A will work at low temps
(and so will R-401A (MP39)) if you change
the oil to AB (alkylbenzene).

Formulations by weight %

R-409A R-22/142b/124 (60/25/15)
R-401A R-22/152a/124 (53/13/34)
R-416A R-134a/124/600 (59/39.5/1.5)
R-406A R-22/142b/600a (55/41/4)
R-414A R-22/142b/124/600a (51/16.5/28.5/4)
R-414B R-22/142b/124/600a (50/9.5/39/1.5)

R600 is N-butane, R600a is isobutane
R22=weak mineral oil miscibility
R124=almost no mineral oil miscibility
R152a=zero mineral oil miscibility
R134a=zero mineral oil miscibility
R600 = very good mineral oil miscibility
R600a = very good mineral oil misciblity
R142b=moderate mineral oil misc, gets much
better when R600a is also present.

Also, FR12 (R416A) has way too low pressure
temp curves (about 12F "warmer" than R12),
so it will make a Fridge out of a freezer
if system or pressures not changed. R416A
with only 1.5% N-butane has almost non existant
miscibility in mineral oil as well.

R-414A has been "FSP" (factory) approved
by Whirlpool corp for maint on R12 equipment.
Whirpool Corp is now the exlusive nationwide
distributor of R-414A. I believe this is the first
R12 replacment blend which has achieved a
major OEM blessing and standing behind it.

For more info on R-406A or R-414A..

http://www.autofrost.com or call 800-622-5008 in
the US.

--ghg, inventor, R-406A, R-414A, Cooltop, etc.
ghg@autofrost.com

Prof Sporlan
17-06-2002, 02:24 AM
George, happy to see you drop by this forum.

Igniting any barbeque grills this summer??? :D :D :D

Sporlan's refrigerants chart which the Prof maintains has the following information on your refrigerants:

R-406A: Tc = 241.7░F, Pc = 708 psia, Vc = ? Mol Weight = 89.86
R-406B: Tc = ?, Pc = ?, Vc = ? Mol Weight = 88.58
R-414A: Tc = 231.3░F, Pc = 682 psia, Vc = ? Mol Weight = 96.93
R-414B: Tc = 226.4░F, Pc = 666, Vc = ? Mol Weight = 101.59

Any additions or corrections will be duly recorded.

zolar1
17-06-2002, 05:03 AM
Thank you George. The data you provided helps me in my decision making process. What is the boiling point of your R406a?

I want something I can put in ANY domestic refrigerator without having to worry about high head pressures and what kind of oil I need to use.

With the R414b, I didn't have to worry about anything except putting it in too fast or in soda pop coolers where I need to consider excessive head pressure with respect to a small compressor capacity.

Can I put your R406A into a frig that takes R134A as a replacement? Or use it in a car A/C system?

zolar1
17-06-2002, 05:10 AM
Here's some of my desires:
(domestic and small appliances use typically)

1) I want to have a nearly 'universal' refrigerant I can use without regard to head pressures or type of oil.

2) A refrigerant in answer to my 2nd most common complaint (My ice cream won't freeze) - ie I need a refrigerant that has a boiling point and decent btu rating such as 'boils at - 40F or -50F'

3) A refrigerant that won't make me have to put my kidney for sale on ebay to afford to buy it.

So far, HotShot is the closest to 'universal' I can find.

zolar1
17-06-2002, 05:14 AM
PS it's a real pleasure to meet one of the creators of a needed product.

Pleased to meet you George!

ghg
17-06-2002, 02:30 PM
I have not lit any more grills since
1996 or so.. after Dave Barry Column
spread it all over the world.. Local fire
dept really got pissed 2 years after the
fact and threatened to turn me in to the
BATF. Doing this now, would surely get
one labeled a terrorist.

There never was a R-406B, there was a
"GHG-HP" refrigerant, only made 3 cylinders
of it.. it was R22/142b/600a (65/31/4).
It was made on a bet from Walt Pasko in
Ft Lauderdale FL, that "There aint no such
thing as an A/C too cold in south FL"..
and this was my response. GHG-HP ran
higher heads (only intended for MVAC -
automotive A/C), with active high pressure
cutoff switches, and condensers were built to
take 450 PSIG. GHG-HP delivered 23-25F duct
air on "max" on 100F ambient humid days.
Evap ran at 19F, and frosted all the way
back to the compressor. GM low side accum
got as big as a football (iceball) after
a long trip. Cont run compressors such
as the V5 needed a "defrost timer" to
off the comp for 15 sec every 3-4 mins to
keep ice off the evap. It sure felt good.
Made it onto the EPA SNAP approved list,
but never into mass production. Cust said
that R406A worked well enough. Limiting
factor was the GM style evaporator which
would blow out at 175 PSIG.. Heat soak
from the engine causes a refrigerant pressure
spike, 30 mins after the engine is shut off
on hot days as the liquid heat pipes from
the condenser back to the evap. GHG-HP
maxxed out at about 150-160 PSIG during
this spike from the heat soak.

Jim Calm's ARTI refrigerant Database listed
GHG-HP as a "candidate for R406B", which
is where you may have seen it, but we never
submitted it.

----

to Zolar1.. ICOR runs around telling you
that HOTSHOT (R-414B) is a "DROP-IN" for
everything, all oils, even PAG..

We try to be a little bit more truthful
then ICOR.

1) Others have told us that in many apps
that R-406A is about as close to a DROP-IN
for R12 that they have ever seen.. But this
must be qualified to being small "DX"
(non flooded evaporator) systems. Those with
Exp valves may need some adjustment on
some systems (Prof Sporlan I am sure knows
more about this than I).

2) R-406A has a "glide" of around 12-15F
at most temps.. simlar to R-409A, 414A, 414B
are all similar performance and glide. R-406A
is miscible in mineral oil at much lower temps.
-40F for R406A, -10F for R414A, +18F for R414B,
and +32F for R409A.


3) Oils.

ICOR says PAG oil is fine with R-414B.
We say to see www.autofrost.com/oil and
see PAG oil turn black in 3 days with
R414B (or R406A, R414A or any CFC or HCFCs)
unless it is the rare "daphne" or double
end capped PAG oil which can tolerate CFC/HCFCs.

It has been known since 1990-91 that almost
all PAGS are totally destroyed by even minute
amounts of chlorinated components, with R11
being the worst.

POE/ester oils.

While R406A, R12 and other HCFCs and HCFC
blends will not quickly destroy POE oils
made for HFCs, we still say to use only AB
or mineral oil in R406A/R414A.

CPI Engineering, a mfgr of POE/ester oils
has told us that it is possible to make POE
oils which work fine in R12, and HCFC blends,
they ARE NOT THE SAME POE/Ester oils which are
made for R134a and other HFCs.. POE/Ester
oils made for R134a and HFCs will become overly
miscible in R12, R406A (and R414B) and HCFCs
and "thin out" too much, kind of like using
kerosene in your engine crankase..

People who have inadvertantly used R406A
in hermetic compressors with POE oil, have
seen them run fine for 2-3 months, then
bust bearings, rods, and other lube related
failures, due to overly thin oil. I am sure
this happens with R12, R414B, R409A, and
other HCFC blends run in POE oils as well.

Lifetime tests with R406A/R414A in mineral
oil have slightly exceeded those of R12
in compressors.. (provided discharge temps
are kept below 300F to keep the R22 component
from breaking down).

Note: if you are using pure AB oil, it may be
wise to add 3% mineral oil, since pure AB
may not "foam". Some older compressors rely
on oil foaming to cover all the bases.

hope this helps
--ghg

zolar1
18-06-2002, 01:13 AM
Yes George, you are very informative!
Now, all I need to do is 2 things - find out where I can buy the 406A and for what price? I already had to sell my unborn son's kidney to buy my last batch of refrigerant...LOL

I usually buy from Johnstone Supply locally, but United or one of the others might be a little cheaper.

Just about all the systems I service are cap tube types. Typically domestic refrigerators, with some soda coolers and reach in coolers.

From what I gather from your above information, I can reasonably assume that i can substitute R406A for any R12 cap tube system and can make the units much colder?

ghg
18-06-2002, 02:41 PM
R406A more info for zolar1

Boiling point. Since R406A is a zeotropic
blend, it boils over a range, called a "glide",
around 15F range. Dew point is about -12F and
the Bubble point is around -26F (R12 BP is -21F).
R406A, R414A/B are pretty much the same in
the bubble/dew points and glide. Mineral oil
miscibility is what is different.

This "glide" causes condensation to take place
a "range", rather than at a single temp. This
expands the "phase change" region in the
condenser, the area where most of the heat is
rejected.. The desuperheating (hot gas cooling
down) and subcooling (liquid cooling down)
regions become smaller.. The phase change region
rejects far more heat than the other two regions.
Since R406A (and the other similar zeotropic
blends) can reject more heat, the cool better
as well.. Often 6-8F colder in car A/C with
orifices.. maybe 2-3F colder in exp valve
car A/C. Pulldown times in fridges and
commercial equipment has been reported to be
much faster with R406A than with R12.. probably
from the same reason.

Bobbie Burke (ATC) in Bloomington, IN, not
far from you, is our main midwest distributor.
Call him at 800-622-5008 to see who may stock
R406A in Cincy. He can also ship to you.

United and some Johnstones used to stock
R406A, however, ICOR's Lies were able to
get them to drop R406A and switch to HOTSHOT
(R414B). It as amazing how dishonesty pays
off in these times.. look at ENRON. You can
go to your United Branch and see if they
still have any R406A left.

Last year, when United switched to Hotshot
from R406A, the locals who had been using
R406A for years were so pissed off, that
they switched ALL of their heating and cooling
business purchases from the Lafayette, IN
United Store over to Leming Supply who
carries R406A. The local United Store almost
went out of business since they lost FAR more
than the R406A sales.. (lost furnace, A/C,
parts, and other HVAC business).. Leming's
business is booming from this move.
--ghg

zolar1
19-06-2002, 01:30 AM
At $195.00 per bottle for the R406A is a bit steep. I thought buying direct would be a lot cheaper, especially with a company who's trying to rectify a bad sitaution and regain consumer confidence (for something you apparently couldn't help)

I figure about $125 to $140 range would be more appropriate of the price since the middleman would be cut out.

My mistake I suppose.

When I can afford it, I'll try the 406a, but it might be a while since I'm a single person business now.

Thank you

zolar1
19-06-2002, 07:46 AM
I read about your "Cryo-seal"

Which version would be needed for the 406a and the 414b?

I couldn't find a price anywhere (as usual).

Thanks again

zolar1
19-06-2002, 04:56 PM
Well George,
No one here in Cincinnati that I could find carries the 406a. Much to my wife's displeasure, I ordered one of your 25lb bottles of 406a.

I asked about being a distributor here, but there is a 1 pallet minimum (yeah, like I have over $8,000 laying around).
I was hoping to maybe be able to drop ship from your warehouse at the distributor prices (cust pays me full price, I drop ship from you to them)

I am a skeptic sometimes. Sorry

ghg
19-06-2002, 07:46 PM
Zolar1, check your email
--ghg

RogGoetsch
20-06-2002, 05:18 AM
Originally posted by zolar1


I need to be able to instantly look at a compressor and instantly know without a doubt if it will work on a refrigerator or whatever. The locked Rotor is the only way to determine this information without having to memorize umteen zillion sets of information.

You see, I take compressors off of one piece of equipment and put them on another piece of equipment. I don't actually need to know what oil is needed since I use R414b.

The bigger the locked rotor rating, the more btu's the compressor can transfer (assume all things being equal) or better yet, the more ***** it can pump & at higher pressures if necessary.

It's hard to know how to answer this, because I don't think you want to hear it. You have found a way of doing things that seems to work and when your misapplied compressors fail, you can blame it on the age of the used compressor or some such. In the interest of others who may pass this way, however, I'd like to set the record straight.

Using the locked rotor rating is probably about as accurate as using the weight. You mention Johnstone as a supplier. Check their catalog. They have lists of compressors for every mfg they sell (as do all wholesalers). You will see that they are rated by temperature range, horsepower, BTU's at given evap temps and by refrigerant. If you are saying you have no room for even a Johnstone catalog, I don't buy it.

In a previous post, you mentioned that you took a refrigerator compressor and placed it on a soda box. Probably a low temp now working as a midtemp. Not a good practice. Profitable, perhaps, but not good engineering.


Originally posted by zolar1
I tried an experiment on my own refrigerator. I measured amp draw of my compressor before adding a 10 ton heat exchanger, and again after adding one.

When I go from 3 amps down to 2, what does that tell you? It tells me that by adding the heat exchanger I am saving electricity.
The theory is this: if the compressor has to do less work, you save money. If the suction side pressure is higher because of a heat exchanger, the compressor doesn't have to compress a 5 psi gas to a 175 psi liquid - it gets a 10 psi gas to work with.

Less work = less heat = less wear and tear = more money saved

Just changing the size and shape of the box........

It tells me that other factors were at work that you did not measure. It requires more work, not less, to compress a higher-pressure (more dense) gas. Remember, superheat is heat added to the suction gas above the temperature corresponding to the saturated pressure. So we're not talking of differences in pressure anyway, but in enthalpy (heat content).

If anything, though, I'll bet the system with the HX was starved and operating at low suction and condensing. This could give you a 33% drop in power consumption, but at lower suction, the compressor would be less efficient and you may have sacrificed 50% of your cooling effect.

Remember, a refrigeration system is an equilibrium system. Changing one factor affects everything in some way. The system will shift to a new set of operating conditions. You need to monitor and evaluate all the conditions before you can truly say you have achieved what you claim.

Hope this proves useful to somebody.

Rog

zolar1
20-06-2002, 06:08 AM
Thank you Rog for the insight.

About the catalog - Yes, I carry a catalog, but I look at the nameplatye on a given compressor and it doesn't tell me a darned thing except volts (SOMETIMES), and Locked Rotor. The rest of the numbers are gobblygook and meaningless to me. You see, I have no 'Rosetta Stone' with which to compare numbers to what the catalog shows. I can match up pictures, but that's about all. The LRA# is what the person who taught me went by, so that's all I know at the moment - hence my reason for being here....to learn more and more. Perhaps he was wrong...I dunno since I have no common frame of reference in which to equate his methods to what most call the 'norm'.

continued.........

zolar1
20-06-2002, 06:19 AM
Regarding the HX I installed - the evap makes a quiet 'whooshing' sound from time to time, and with the controls set midway, the freezer hovers around 0 deg F, the bottom around 35.

Just for the record - I'm not into perpetual motion machines. I look at things a little differently and try to apply other principles that DO work in areas that seem to defy reason. Sometimes it pays off, sometimes it doesn't.

I believe Albert Einstein made the statement, "Genius is 1% inspiration, 99% perspiration", but I could be wrong.

As long as an Idea works and and costs less, does that diminish the value of the idea?

ghg
20-06-2002, 01:36 PM
Rog is correct, one has to be careful
on "non standard" uses to make sure parameters
are not exceeded. Using a low temp compressor
in med or hi temp use can result in overloading
it and shortened life. Low temp compressors
have more displacement per HP than med or hi
compressors, since they operate at lower suction
pressures.

Sometimes you see a compressor that can
be used under multiple service conditions, but
the refrigerant is changed to make up for
the displacement per HP factor.

Sometimes a given compressor will be rated
for low temp using R502 (higher pressure
refrigerant), and for Med and Hi temp
service using R12.

One should always monitor the compressor
discharge temp as part of service or
experimenting, especially when "pushing
the envelope", like trying to make a household
fridge do -30F for extra hard icecream ,etc.

A thermocouple or bead type thermometer should
be used to check compressor discharge temp,
right at the CAN. It no case should it
exceed 240-250F.. since at those temps, the
temp in the discharge valves is at 300F.

Above 300F R22 (in most of the R12 replacement
blends) will break down and make carbon and
acids.. And a few degrees hotter, the oil
will start to char..

--ghg

herefishy
20-06-2002, 06:23 PM
In horizontal ice cream cases such as those manufactured by Hussman, the Copeland (low temp R-12) semi-hermietic compressor is not even rated for R-502. Hussman (and other manufacturers) will utilize these for very low temp R-502 at -30F to -40F evaporator in a cap tube system.

But do you know what? Don't use 408-A as a replacement. It doesn't work!!!!! I'm not sure what it is about it.

Any ideas? :confused:

ghg
20-06-2002, 07:36 PM
Did you charge the R-408A as a liquid?

All R-4XX refrigerants need to be liquid
charged or their composition will change.

R-408A is composed of: (weight %)

R-125/143a/22 (7/46/47)

Neither R-125, nor R-143a are miscible in mineral
or AB oil at all, that leaves R22 which is
very poor in mineral oil at -30F.

AB oil would be a MUST I would think or mix
in some POE oil.. or a squirt (upto 10%)
of R-290 (propane) would make the AB oil
return ok. "Zerol" is AB oil.

What didnt work about it?
--ghg

Prof Sporlan
21-06-2002, 12:43 AM
I believe Albert Einstein made the statement, "Genius is 1% inspiration, 99% perspiration", but I could be wrong.

The statement is accurate, but Thomas Edison is credited with it. :)

He also said: "If we all did the things we are capable of doing, we would literally astound ourselves." :)

zolar1
21-06-2002, 01:49 PM
You're right Prof ...Right Quote, wrong person...LOL

zolar1
21-06-2002, 01:56 PM
Regarding life span of the compressors I use - I can get used compressors regularly andf keeps a small stock of them on hand. If one goes out and the item is still under my 90-day warranty, then I'll replace it.
My customers don't care about quality. They just want it fixed CHEAP. Hence, I use used compressors and HotShot (for the time being anyway), which is what manufactureres call 'designed obsolence' or 'designed service life'

As long as it lasts just beyond my 90 warranty, my conscience is clear (unless they want to pay be fair market value for goods and service rendered).

I want to learn more about this trade. It seems my past mentor's training isn't "gospel" and I am weak in many areas. But this will change. Starting with this place, and the R406a I'm buying.

zolar1
24-06-2002, 04:39 AM
Aiyub,

I think I may be able to mail you a sample of my homemade HX's.
I made 2 of them, one larger than the other. (Now if I can just remember where I put them...lol)

I origionally made them to reduce flask gas in the cap tubes, but discovered that they can make the freezer part of a domestic frig colder if the HX size isn't too big. (I have a way to sort of boost the performance a little.)

You see, I was modifying domestic refrigerators to accept a normal compressor instead of the junk rotary compressors (which usually failed) that came on some of them. It takes me about 3 hours to redo one of them from start to finish. I noticed that the freezers barely got to +5 or+10 before adding the HX. Once added, the freezers got to -10F without any problems.
Many of them are still in use today, long after the 90 day warranty expired.

Zolar

zolar1
24-06-2002, 04:45 AM
Also, I got out my Johnstone Supply catalog. NOWHERE in that catalog is there a conversion chart for ANY of the numbers on a compressor nameplate.

Sure, you can look up a compressor by application, but nothing tells me who makes a given compressor, what it's application is, nor what kind of oil it uses.

So, when some scrapper hands me a compressor, I can only go by the LRA number and volts if it's listed.

The 134a compressors are usually labeled though, so I can assume the type of oil in them.

stevec
25-06-2002, 03:25 AM
Zolar1
I recall an article in the Ashrae magazine a couple of years ago that had a case stated for using mineral oil in R134.It was to do with diary case type cabinet refrigeration.
Must see if i can dig it out. Theoretically anyway it was reasonably interesting argument put forward.Never saw any feedback..Maybe the guy is still paying for it.but...

How do you guys get on when recharging systems when they develop a leak in a part of the system where fractionlised takes place. Do you recover all and charge with new refrigerant.

zolar1
25-06-2002, 04:35 AM
Wellllllllllllll,

In domestic frig's, fractionalization doesn't seem to be too big of a problem, unless it's very severe.

ICOR recommends that you recover and recharge with new refrigerant if fractionalization occurs. But really now, how can you tell on somebody's frig if it happens??

From what I understand, the R22 component of HotShot is what is lost first. I know a few that simply pull down the system, fix the leak, put it back in, add more refrigerant, and 'ship-it' without any problems.

About mineral oil and 134a....

I went to a site listed from one of the super-fixers (Prof Sporlan maybe???) and saw a cap tube bleed off from the high side to the low. Perhaps 134a could be used in such a system with mineral oil provided an oil seperator and oil return line could be utilized, especially on a long vertical run. Then oil return would not be a problem?

zolar1
25-06-2002, 05:01 AM
Anyone hear of a product called "Cool Up'?

It's sold in Canada and US techs can buy it with a credit card.

Anyone know what it really is???

Purportedly, you only use 1/2 as much charge as R12 listing, and get MUCH colder than R12.

Cost is about $1.00 (US) per oz, sold in 6oz cans or 25lb bottles.

DaBit
28-06-2002, 11:22 PM
This thread caught my attention with the idea that suction gas / liquid line heat exchangers do not add efficiency. But do they increase performance? If I think about it, they should not increase performance either.

But I found a little performance gain in my current R134a based water/methanol chiller when I added a heat exchanger (simply wrapping the captube around the suction line). It could be due to a reduction of flash gas in the captube, I don't know. It's there, and I am just doing my first steps in the realm of refrigerations.

But now I want to change to a TEV since I experience huge load variations on the evaporator. A TEV is supposed to cope with that better than a captube.
I planned to add a little HX too, with the main purpose of increasing superheat at the TEV bulb, and reducing the risk of flashing before the TEV. I would make the HX by just brazing together the suction line and liquid line for about a feet or so, and eventually wrapping it with copper wire to increase heat exchange.

Is this still a good idea? I am not really concerned with the COP of the chiller. Performance is more important.

Zolar1:

In one of my first test setups, an R12 compressor filled with mineral oil failed when charged with R134a. The oil was quite acid, so it might have failed due to moisture.

About your teacher: 10 engineers have 10 different methods of solving a problem. You teacher found that comparing LRA# is a valid method of selecting compressors.

I do not agree. Motors with very different HP ratings can have the same LRA# rating. It is just dependant on the thickness of the wire used, the amount of wire used, and the quality of the connections. Not on HP rating.

stevec
29-06-2002, 12:20 AM
I read an article in the Ashrae magazine talking about the practicalities of this or not as the case may be.

It was a couple of years ago but the article was interesting.
Some of his headings were;

Improved working viscosity
Reduced refreigerant charge
Faster refrigeration on start up
Reduced slugging
and on
All in all including a few potential problems (and that can start a thread on it's own proberly)
it made interesting reading. I've not tried it, anyone out there?? who has and lives to tell the tale

hvac01453
30-06-2002, 01:37 AM
when charging these small compressors and only the LRA is available, divide it by 6 and this will generally give you a reasonable FLA rating. The other thing is We carry two manuals that cover 90% of all the compressors in our area, Copeland and Tecemseh. The heat exchanger discussed is manufacturered by Sporlan called an "ALLS Valve", although Sporlan bought purchased the patent, they addmited it's efficiency is questionable at best. The heat exchanger sounds like pie in the sky engineering, It appears to be working like an unloader, pump the heat out and put it back in the low side, its an unloader, the run times will be longer is all. There's your missing amp.

zolar1
30-06-2002, 03:45 AM
In my area, I know of an appliance dealer (used) that just dumps R401a into a frige and sends it on it's merry way to an unsuspecting customer. While his choice in refrigerant seems OK (colder frige I assume), one cannot help but wonder if the consumer has the right to know that their refrigerator WILL BE breaking down because of poor workmanship.

Which is colder for a frige: R401a, R401b, or R409a?

I am still struggling with customers crying incessantly that their frige won't freeze ice cream and that their 'old' frige always did.
If I put any more refrigerant in (or run the psi low) then I risk compressor failure.

Also, people still want their 5000btu A/C to blow out sub freezing air. They scoff at paying $150 to $200 for a decent A/C and want me to perform a miracle by 'fixing' their 5000 btu A/C to cool 5 rooms. Without switching to some expensive refrigerant like the R500+ series, is there anything better than R22 for a window A/C?

ghg
30-06-2002, 10:38 PM
R134a in mineral oil.

If you have a downhill run from the evaporator
back to the compressor, it may work.

uphill or horizontal, the mineral oil does not
flow evenly along the walls of the tubing, but
builds up until the line plugs up, and then
flies back like a "snot" glob or a bullet.

The high side liquid line sight glass will also
look like "milk" instead of clear, since you are
seeing a fine "dispersion" of oil droplets in
the refrigerant, but not dissolved, like shaking
up vinegar and oil salad dressing.

--ghg

stevec
02-07-2002, 03:06 AM
I remember reading an article in a 1999 ASHRAE magazine that gave arguments for using mineral oil with HFC's. It was well written and included some reasonable points.

Has anyone actually done this in the field.

Prof Sporlan
04-07-2002, 01:04 AM
The heat exchanger discussed is manufacturered by Sporlan called an "ALLS Valve", although Sporlan bought purchased the patent, they addmited it's efficiency is questionable at best.

Ahemů.. the ALLS heat exchanger is manufactured by ALCO, originally under a license agreement with its inventor.

zolar1
07-07-2002, 07:38 AM
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
07-07-2002, 06:30 PM
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
07-07-2002, 08:30 PM
Thank you herefishy for your insight. Much appreciated.

superheat
19-07-2002, 07:14 PM
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
19-07-2002, 11:24 PM
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
21-07-2002, 04:17 PM
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
22-07-2002, 03:35 AM
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
22-07-2002, 01:54 PM
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
22-07-2002, 05:25 PM
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
28-07-2002, 02:11 PM
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
28-07-2002, 06:12 PM
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
28-07-2002, 07:30 PM
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
28-07-2002, 08:04 PM
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
28-07-2002, 10:58 PM
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
29-07-2002, 04:13 AM
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
29-07-2002, 04:56 AM
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
29-07-2002, 05:36 AM
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
29-07-2002, 09:38 AM
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
30-07-2002, 02:51 PM
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
31-07-2002, 04:45 AM
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
31-07-2002, 05:01 AM
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
31-07-2002, 06:23 PM
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
02-08-2002, 01:31 PM
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
05-08-2002, 03:47 AM
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
05-08-2002, 03:53 AM
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
05-08-2002, 04:48 AM
Here is a link for more information on HC refrigerants.
http://ctan.unsw.edu.au/pub/archive/HC/HC.html

zolar1
20-09-2002, 06:34 AM
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
02-11-2002, 09:34 PM
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
10-05-2003, 11:46 PM
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
10-05-2003, 11:46 PM
double post please delete. sorry

zolar1
26-05-2003, 07:19 PM
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
30-05-2003, 01:56 AM
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
16-02-2004, 03:05 AM
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
17-02-2004, 01:19 AM
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
19-04-2004, 09:42 AM
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
19-04-2004, 12:02 PM
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
04-07-2006, 06:50 AM
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
05-08-2006, 08:29 AM
Hello everybody