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slingblade
30-09-2005, 03:17 PM
I thought i had seen it all. about 5/6 months ago i came accross this idiot. http://home.earthlink.net/~lenyr/refrig.htm
I did e-mail him to point out some obvious safety issues but all i got for my trouble was a reply telling me to chill out. basically he has posted diy fridge instructions to kill yourself. take a look.

fridge51
30-09-2005, 04:55 PM
better still from the same guy
http://home.earthlink.net/~lenyr/refrig2.htm
perhaps he is not quite sane

chemi-cool
30-09-2005, 09:00 PM
The guy is not the problem. his life expectancy looks pretty short to me:D

The followers are the problem.



Loved this picture.

Chemi

Peter_1
30-09-2005, 09:46 PM
R600 is propane and pressures are almost the same as R12.
Many fridges works these days on propane.

US Iceman
01-10-2005, 12:30 AM
Hi Peter,

If I remember correctly R290 is the refrigerant designation for propane and could be used as a replacement for R22.

R600 I believe is for n-Butane. (again a possible replacement for R22)

R600a is for iso-butane and could be used as a replacememt for R12 or R134a.

Propane is a really good refrigerant as long as you use the correct oil for the compressors. For large R290 systems, the electrical systems have to be classified as explosion proof, which makes them very expensive.

How does Europe allow propane in domestic refrigerators? Is the refrigerant charge limited to a small enough volume to limit the flammable concentration? :confused:

Peter_1
01-10-2005, 07:49 AM
You're right: R290.

A friend of my is a teacher HVAC/R.
Almost 10 years ago, if not more, he did a test in school. He evacuated the R12 out of a domestic freezer and filled it afterwards with propane.
He measured pressures and currents before and after the replacement and he said that there was no noticable difference.

Many of the new European domestic freezers I see in the shops are filled with R600 or R600a (never looked so well to the nameplates because we never service these things)
I see R600 from far on the nameplate and wasn't aware there was also R600a excisting.

chemi-cool
01-10-2005, 07:56 AM
Peter,
Are you saying that I can simply do that on small fridges and freezers?
Is mineral oil OK?

I have to check If we use here propane or butane,
Is there a difference between the two?

Chemi:)

Peter_1
01-10-2005, 07:16 PM
The pressure of propane is higher then butane.
He did it with propane as far as I can remember.

We also use propane instead of the expensive acetylene.

US Iceman
01-10-2005, 07:48 PM
Hi guys,

If I remember correctly, propane and oil has similar problems as R12 and oil; they are very miscible and soluble when mixed together in a refrigeration system.

The oil should be selected for the refrigerant and operating conditions. On the large propane systems I worked on I think the oil we used was made by Mobile (poly-glygol, or something like that. I do not remember the exact name)

According to the pressures, R290 is almost 50% higher than R12 for the same saturation temperatures.

Iso-butane (R600a) has pressures about 50% lower than R12 at the same saturation temperatures.

If we look at the mass flow comparisons (with propane being the baseline at 1), we find:

The mass flow ratio for R-12 is 2.37 times higher than propane, and,

For iso-butane the mass flow ratio is 1.07 times higher than the mass flow of propane.

R22 has similar pressures to R290, but the required mass flow for R22 is about 70% higher than propane.

This is based on the liquid refrigerant temperature at 37.7C and the evaporating temperature at -6.6C.
The molecular weight for each is:

R12 = 120.9
R290 = 44.1
R600a = 58.13
R22 = 86.47

Iso-butane has a much lower pressure than propane for the same temperature. Propane and R22 have the highest pressures of the refrigerants above.

Hope this is helpful to you.

US Iceman

phil
01-10-2005, 08:18 PM
hi there tried to put r134a into a r600 bottle cooler just out of curosity and could not get the damn thing to go below 14 degree celcius (that means warm beer so that got thrown away)

some muppet in the uk got himself killed by trying to braze a r600 unit with the gas still in it!

you can keep it as far as i am cincerned but our european cousins love the stuff especially the germans!1

you have to do a training course even to by it in the uk

chillin out
01-10-2005, 11:30 PM
Hi Phil,

hi there tried to put r134a into a r600 bottle cooler just out of curosity and could not get the damn thing to go below 14 degree celcius (that means warm beer so that got thrown away)

I have done this several times with success.

What you have to do is cut off 3/4 of the capillary and change the drier.

:) :)

Bones
07-10-2005, 09:03 AM
hehehe my favourite quote from his speil...

"a valve (V3) was inserted to be used as the expansion valve. This is the valve that takes the place of the normally used capillary tube. The valve has to be adjusted all the time as the temperature changes and is quite critical. This is one of many reasons why this system is not about to replace the refrigerator in my kitchen. "

i just read down to the Opreating Procedure... please...

Karl Hofmann
07-10-2005, 12:22 PM
It is not unusual for American DIYers to charge their old R12 car aircons with HC refrigerants, and to be fair they do work well, Even found a few here in the UK, HCs work well with mineral oil, however car a/c is designed to leak, and the components are all placed in far too vulnerable a place for my liking, plus the cars insurance would be null and void if it was found to have contained HCs in the aircon. Domestic fridges, I have no problem,with , they are assembled in a factory under controlled conditions. Dealing with HCs is not beyond the capabillity of anyone here provided you use your noodle, suggesting that the general public can mess around with it is asking for trouble, we all know how daft the general public can be.

My Bosch fridge freezer uses R600, and it gets the thumbs up