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Posted: Sun Apr 28, 2002 5:32 pm Post subject:

Well I changed my h2o system, added a res to remove left over air. Should reduce noice further if thats possible. Next up is dump the cube and going to different one. Flow rate isnt all that it can be. Temp is currently 36c at chip and exit water temp is 23c.

I'm thinking that heat exchange isnt that good. using mase2 that I lapped and using thermal paste.

[img]http:\\64.66.133.162\images\p4280001.jpg [/img]

MCSE 2k
MCSA

Posted: Sun Apr 28, 2002 6:50 pm Post subject:

I wish I could send the pics of the frezzer unit I built.
Cost me a pretty penny, but I can freeze water rather rapidly with it.
I'm looking for a fulid that remains a liquid below freezing, and that has good thermal properties (I thought about vodka, but that stuff can go up in flames)

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Posted: Sun Apr 28, 2002 6:52 pm Post subject:

well you have to worry about the thermal transfer rates, but anti freeze maybe your ticket.

MCSE 2k
MCSA

Posted: Sun Apr 28, 2002 8:00 pm Post subject:

Crap. I spent most of an hour typing a response and then dropped the keyboard. duh

Here's a shorter version:

Adding stuff to water lowers the freezing point. Alcohol is okay. You'll need to stay below 50% ethanol to reduce the flammability hazard, and you'll have to seal the system to reduce evaporation losses. Adding an inhibitor would be a good idea.

Non-toxic ionic salts like sodium chloride (table salt) or calcium chloride can work in industrial environments where control of pH and inhibitor level can be maintained, but I wouldn't recommend it for home use because of the risk of accelerated galvanic corrosiion.

Automobile antifreeze is usually mostly ethylene glycol with some inhibitor. Ethylene glycol is toxic, but it does not vaporize easily and it is not readily absorbed through the skin, so avoid drinking it and wash your hands after handling it. A 20% (by weight) solution of glycol freezes around -11°C, while a 60% solution freezes around -48°C (estimating from a tiny chart). Viscosity goes up with decreasing temperature and increasing glycol concentration, so your circulating flow rate will drop. (A 60% solution at 0°C is about 10 times as viscous as water at standard conditions, while a 60% solution at -40°C is about 100 times as viscous.) Thermal conductivity and heat capacity also go down, so the ability of the circulating system to remove heat is lower than with pure water.

Note that once you cool below ambient, you must be cautious of condensation. If your tubing is colder than the dewpoint of the air, you'll have water dripping in places that you do not want. Sub-freezing systems add the additional problem of ice buildup. You can have a flood when a poorly-insulated sub-zero refrigeration system is shut off and the accumulated ice melts.

Looking at the 13°C delta T that you posted, your waterblock may not be transferring heat as well as you would like. I have a similar delta T on a stock AthlonXP 1700+ with air-cooling from a relatively-quiet low-rpm 80mm fan.

:pawa1:

Posted: Sun Apr 28, 2002 8:21 pm Post subject:

Im not sure if I believe MBM. Still getting air bubbles out of the system, so I could still be seeing some problem there. Truth is more than likely somewhere near the middle of the temp range.

My goal was to have a silent system and Im getting close.

MCSE 2k
MCSA

Posted: Mon Apr 29, 2002 10:56 pm Post subject:

Not to knock anybody, BUT, all that effort spent on watercooling and you get 36C? I get 41C under a full Seti load using a Vantec. My normal temp, like now for example, is 38C. Just seems like a lot of work when it's only 2c less than mine.

I know I know. You're gonna say building and experimenting is half the fun and if that is, in fact, what you are going to tell me, then I would have to agree with you there. And I also agree that your goal of a silent system warrants the use of watercooling. I just find it amazing that I get similar temps with no water.

Life is a like a box of chocolates, when its done its done.

http://wilsonthedog.homestead.com/home.html

Posted: Mon Apr 29, 2002 10:57 pm Post subject:

Oh, and good luck with it.

Life is a like a box of chocolates, when its done its done.

http://wilsonthedog.homestead.com/home.html

Posted: Tue Apr 30, 2002 3:02 am Post subject:

The biggest issue is that I have the cube, learned late in the game that it wasnt the best. Silence was the biggest concern for me.

As for temps, I think mbm isnt that accurate. The in thermal couple is reading 23c. So I'm betting chip temp is lower than the 36 but higher than 23. Also system is on 24 7. Seti is demanding and WU's is goal.

MCSE 2k
MCSA

Posted: Tue Apr 30, 2002 12:53 pm Post subject:

Yeah good point about Seti. MBM has been known to inaccurate at times. I use cpucool but, honestly, maybe that isn't so accurate either.

Life is a like a box of chocolates, when its done its done.

http://wilsonthedog.homestead.com/home.html

Posted: Wed May 01, 2002 3:17 am Post subject:

I think problems with MBM, CPU Cool and even the BIOS temp. reports are often caused by the mobo's hardware monitoring chip rather than a bug in the software.

Posted: Wed May 01, 2002 6:51 pm Post subject:

Hmmm, that may very well be true. I guess the only way to know is with a temp probe which I am lacking.

Life is a like a box of chocolates, when its done its done.

http://wilsonthedog.homestead.com/home.html

Posted: Wed May 01, 2002 8:25 pm Post subject:

Another point is room temp is creeping up with the advent of spring, so that will also increase temp.

I like the use of H20 and I think its a good alternative. Like all things, its the chase that is the best.

MCSE 2k
MCSA

Posted: Wed May 01, 2002 9:07 pm Post subject:

I've often thought about using one of those office water coolers to water cool a pc... Being the lazy ass that I am I just haven't got around to building it yet

Posted: Wed May 01, 2002 9:29 pm Post subject:

From memory 3M make a whole range of non conductive fluids that would be great for a liquid cooling setup.

Quote:
3M™ Novec™ Engineered Fluids and 3M™ Fluorinert™ Electronic Liquids are available in a wide range of boiling points (as high as 215°C) and freezing points (as low as -138°C) to meet specific heat transfer requirements. Novec fluids have low global warming potential (GWP) to help meet voluntary PFC emission reduction targets.

Novec fluids offer you:

Reduced PFC emissions
High dielectric strength
A wide range of boiling and freezing points
Low maintenance
Chemical inertness and non-corrosivity
Good material compatibility
Low toxicity
Zero Ozone Depletion Potential
Nonflammability
Non VOC
SNAP approved

More info at 3M

Posted: Fri May 03, 2002 7:04 pm Post subject:

dosent that stuff cost like 80 bucks a PINT though?

More Posts untill I get another dawg in the pound

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