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OT: Refrigeration Compressor fix

Not really the right newsgroup but since your family!

I was cooling my computer using oil and a refigerator compressor I tore out of an old mini-refigerator I had back from school.

It was working well keeping my computer's temp at least 10 degree's or more cooler(initially it would be at 10-15 degree's celsius and ramp up to about

30-35. Without the cooling it runs about 45-50(with oil) which is what it runs with just air cooling.

Anyways what happaned was the compressor froze the water(Which is pumped through the oil using copper tubing) because the pump stopped working(basically... it's pumping at it's peak height). I didn't realize it was froze so I tried lifting the ice carriage thingy(basically the expander that actually get's cold in the fridge) and it broke releasing the gas(maybe I shouldn't say that... will I be fined or have to pay some type of carbon credits? Hopefully I won't get arrested).

Since the computer is running a bit too hot I want to salvage the idea. (bad enough it's in oil which is distributed the heat almost completely among all the components)

Would it be possible get some of the freon(I've seen some at walmart) and fill it back up? I'm not sure how difficult this would be but it would give me an oppurtunity to re tube to make it function a bit better.

What I was thinking is that I could put a valve on the tubing so I could add the freon(or whatever it's called today) but I imagine I have to add just the right amount at the right pressure? But surely it wouldn't be too difficult to rig something up? Of course it should be cheap else I might as well just buy a new water cooling system for my computer ;/

Any ideas?

Reply to
Jon Slaughter
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Contact "Skybuck Flying" ?

martin

Reply to
Martin Griffith

Buy a little 1 cu.ft. refrigerator at Walmart (for

Reply to
Jim Thompson
[...]

Overkill. If you are running at 45C-50C you should be fine.

Most cpu's have a maximum temperature between 65C and 95C. The problem is electromigration, which increases with temperature. But if you are below the max specified, you should expect long life.

See the following for a brief list of max cpu temperatures:

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See Chris Hare's "Processor Electrical Specifications" page for more maximum cpu temps:

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If you want to reduce the cpu temperature a bit, clean the lint and dirt from the heat sink and fan. I use a bit of diluted dish detergent and wash it off with running water. Hold the fan face up or at 45 degrees to keep soapy water out of the bearings so they are not damaged. Use a scrub brush with long bristles to clean down inside the heatsink fins.

Be sure to clean the main chassis and power supply fans also. As long as you are there, use a vacuum to clean the lint and dust from inside the computer. I use an ordinary paint brush from the dollar store to clean the lint from the capacitors and memory cards. I have not had any problems with ESD.

I found the expensive silver heatsink paste to be a waste of money.

It is difficult to get a thin uniform coat, and the silver particles don't conduct heat as well as claimed. The particles are not in very good contact so they don't act like solid silver. (I use pure silver wire in some applications, and it conducts heat extremely well.)

Instead of silver paste, I use a thin coat of plain high-temperature marine grease applied to the heatsink and the cpu. When installing, move the heatsink sideways and rotate it slightly to eliminate any air bubbles.

The cpu temperatures are almost identical to the results with silver paste, around 40C to 41C. I think the reason is the film of grease is much thinner than the silver paste, so the thermal conductivity is pretty good. Anyway, 40C is fine.

I reversed the main fan to blow cool air into the computer instead of out, and cut a small baffle from a polystyrene jug to direct the cool air over the cpu heatsink. You have to figure out how to mount the baffle. In my case, there was a convenient stud, so I cut a slot in the edge of the baffle and let it sit on the stud.

If you still want to lower your cpu temperature, get a bigger heatsink and add a cooling baffle.

Another area to watch is the disk drive temperatures. The drives are often enclosed with poor air circulation, so they get hot and will die early. If so, you need to add a small fan to bring in cool air.

With a clean system, I was able to add small resistors in series with all the fans to slow them down. This eliminated the constant whine and still keeps the cpu temperature well in the safe region.

Good luck.

Regards,

Mike Monett

Reply to
Mike Monett

100 bucks is a *lot* cheaper than the tools needed to recharge your compressor. 
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Joe Chisolm
Marble Falls, TX
Reply to
Joe Chisolm

Do you have a good vacuum pump to purge the system? Without purging it will only ice up again some time.

Reply to
JosephKK

Oil has a lower specific heat than water. Why are you cooling the computer with oil?

Oil? Water? How many stages does this claptrap cooling system have?

Most of the liquid cooling systems I've seen are heat exchangers direct to water, then through a remote radiator to the air. Your oil stage may have resulted in the subsequent oil to water exchange not delivering enough heat to the water to keep it from freezing. To move the same amount of heat that chilled water can absorb, the oil has to be so cold that water in the system will freeze.

The kit needed to refill a refrigeration system will probably cost you more than a new (non CFC) refrigerator would. Better yet, re-design the system to eliminate the compressor and the oil.

I know this flies in the face of all the PC modders philosophy, which appears to be to add as much crap to a system as possible to impress other PC modders. When nothing more than a couple of decent fans will do the trick.

--
Paul Hovnanian     mailto:Paul@Hovnanian.com
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Personally, I\'m against people who give vent to their loquacity by
extraneous bombastic circumlocution.
Reply to
Paul Hovnanian P.E.

...

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From that post, he has the computer filled with 5 gallons of vegetable oil. Using water the same way would end up with corrosion and shorts.

I'm not able to tell from his recent problem-description whether his water pump (and presumably a radiator cooling fan) are in use now. While a temperature range of 45-50 might be acceptable in a fully-passive system, it would be marginal if it entailed a noisy pump and fan.

[snip rest] 
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jiw
Reply to
James Waldby

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I didn't catch the details of the oil cooling. That said, the commercial water cooling systems use heat exchangers in contact with the CPUs and GPUs (the big heat producers).

Its possible to route the water plumbing to a remote location where the pump and radiator fan noise are not an issue.

--
Paul Hovnanian	paul@hovnanian.com
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Have gnu, will travel.
Reply to
Paul Hovnanian P.E.

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