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CPU Convective Water Cooling
biso writes "The possibility of cooling a CPU with gravitational convective flow of water is here analyzed and experimented with positive results.
Many liquid cooling systems have been experimented by overclockers to better dissipate the heat from CPUs. The major part of these coolers is characterized by a relatively complex system requiring pumps or other active devices. Sometimes even liquid nitrogen is used. I built a simpler cooler, able to dissipate the same heat flux of a normal heatsink."
He's going to be boiling noodles in a minute
Banaaaana!
ok, i can see the extra bit of silence from not having a pump would be nice. but ... isnt a bowl of water on top of your computer just asking for trouble? something tells me this guy doesnt have cats.
I've built numerous different water cooled systems, and the $20 pump from the aquarium supply place is NOT the most complex piece. A good waterjacket for the cpu is by far the most complex and generally most expensive single piece, and also the one that is most critical for good performance. Still need the waterjacket in this design, so it isn't really saving anything...
It's cheap, reliable, odorless and environmentally friendly, and refills are available everywhere. I myself have been using a 78% nitrogen gas mixture at 14.7 PSI to cool all my computer components for years now. Where did I get the idea? I guess I just pulled it out of thin *SMACK*
I really think that phase change cooling systems are the future of the PC. Only with phase change cooling systems do you get high quality cooling able to remove the utmost heat away from a CPU and cool it to below freezing.
I saw a presentation by Intel last year in which it pointed out that modern CPU's emit more heat per area than molten lava, and they expect that within a few years they will emit more heat per area than the sun.
With these considerations passive water cooling is only a good first step and bound to be insufficient, even over the short term.
...using sponges as sound dampening material inside the case. Who knows, it just might save your computer when somebody bumps the frickin' table and dumps that bowl full of water over everything!!
While I admire all of those who are willing to actually pipe water into their computers for the sake of keeping them cool, I am still more than a little frightened of this idea. Knowing me, something would end up leaking (probably through fault of my own) and my precious tower would go up in a ball of flame or some such. Rather, I choose to take your regular old air cooling and make it more effective. Through proper cable management, good airflow paths, a set of nice quiet fans, and the ability to control them with respect to how much they are needed, I keep my fan almost as cool as a friend of mine who does have a liquid cooling system, and with very comparable noise levels. If you're willing to do some work and set up a decent air-based system (and be willing to clean out the dust), there's no need to balance a bucket of water precariously on top of one's computer... : |
that picture of a bowel of water on top of an open pc tower case is not something I would necessarily run....
Bowels of water on his PC, this is something I definitely DON'T want to see!
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I leave the sides off of my computer for better air flow and less dust collection, but mainly because I'm too lazy to put in case fans.
Since my case has to sit on top of my desk, this also gives me a little more space to put stuff (inside the case, out of the way of boards / wires etc).
What do I keep in there? First is the reciever for my wireless keyboard / mouse, the syncing cradle for my handspring visor edge, and a few important papers. Those are the things that don't really move.
The fun things in there are the mountain dew beer glass, the caffeine shot glass, and usually 2 - 3 open cans of dew. All have soda / caffeine in them and are actively used.
No, nothing has spilled yet, and yes, I do have cats. 3 of them. They know that if they go near the sacred tower, they get stuff thrown at them (usually a slipper, but on occasion a t-shirt if I find that first).
On a side note: I in no way have the balls to water-cool my case, other than replacing the cold soda every 30 minutes.
Work sucked, until it became unemployment, when it became slightly more tolerable. -Tet
Nah... I'd use transformer oil, and I don't think a Lipton Cup-a-Soup would taste quite the same.
Transformer oil, however, is probably quite suitable for use in a CPU cooling system.
It has a higher breakdown voltage than air and is almost infinitely less conductive than real-world (ie. impure) water. Transformer oils are specifically designed for use as an insulating material in large power distribution transformers. Electric utility transformers at power substations, operating in the range of hundreds of thousands of volts, would arc between windings if the oil leaked out of them and air - with its lower breakdown voltage - seeped in. (Air breaks down at about 3kV per millimeter.) You can feel pretty confident that leaked oil won't short out IC pins on your motherboard. Hell, you could also ditch your power supply fan and fill that full of oil, too - just beware of relays and other mechanical components.
Heat transfer is a big reason for oil, too. In a car engine, much of the heat is generated by friction in the bearings, and motor oil pumped through the bearings takes that heat away. Transformer oil doesn't have to lubricate, nor does it have to carry away huge amounts of impurities or combustion by-products as in a car engine - the biggest requirements are heat carrying capability and high breakdown voltage. Large pole pigs (pole-mounted power transformers) are usually oil-filled and often have pipes coming from the bottom and going to the top - they serve as radiators. Oil flow is not by pump, the reliability would be too low - they're convective, too.
Finally, viscosity. Yes, this might be difficult, but transformer oils are available in a variety of thicknesses. You want a viscosity corresponding to SAE 0, which is the same as water. Even less might be available, though I've personally never seen it.
Density changes with temperature rise will have to be considered, since the lower density of hot liquids causes them to rise in the system (and is also the physics behind lava lamps). The system that guy designed is based on the density changes of water. Transformer oil won't behave the same way; accordingly, you'll have to whip out the old slide-rule and do some math. Calculus is your friend. Fortunately, the data on transformer oil should be readily available, it's an important design criteria.
Voltesso and Diala are good trade names which I've personally used in transformers loaded to hundreds of kilowatts at over 250,000V, at RF frequencies. (FAA obstruction lights on large VLF radio transmitting towers.) They're ALL PCB-free, and while you don't want to drink it, they're no more toxic than motor oil. And it takes a hell of a lot of work to make them catch fire.
In short, transformer oils are available in a variety of viscosities, are specifically engineered for their thermal transfer capabilities, are not electrically conductive, not dangerous, and are suitable for almost all of your electronic cooling needs.
The only problem I forsee is that you're gonna have a hard time buying them in quantities less than 45-gallon drums... though the drum would make a great passive radiator. Seriously, talk to a couple of linesmen with your local power utility, maybe you'll be able to talk your way into a couple of gallons of it.
And once that's done across all the machines in your compile farm, you can get to work tackling the big problems of why Linux isn't ready for the desktop yet.
Fire and Meat. Yummy.