Slashdot Mirror
Aquarium Full of Oil For PC Cooling
JaredOfEuropa writes "Forget fancy watercooled CPUs or complicated heat pipes. Annoyed with the noise of the forced-air cooling in his computer, this guy simply dumped his entire motherboard in an aquarium filled with mineral oil. (coral cache). No modifications were necessary; he even left the fans running to keep the oil moving about. The only thing not submersed in oil is the hard disk."
The reason that you can't submerge electrical parts in water is the simple fact that water is electronically conductive given the presence of electrolytes (which is so hard to guarantee against in practice, that you can rest assured that water is bad.) Many oils, however, are not electrically conductive. Therefore, as long as the medium used is electrically inert and does not chemically react with anything you're submerging in it, you can consider it a viable medium for immersion cooling assuming that heat transfer properties are favorable.
This has been done before. Interestingly, some projects have looked to it for outdoor computer use (stationary) due to the water-repellant properties of many oils.
I'm an elevator Engineer. This reminds me of a very old residential elevator controller I saw recently that was installed in 1917 and still had all the original equipment in good working order. The controller was in a cast iron tub with all the relays mounted to the lid and suspended in transformer oil. There was a hoist in the ceiling to enable lifting the lid for access to the relays. It would cost a fortune to build something like that today, but it certainly was durable.
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
Even with no heat loss to the air, I've got 10 minutes per degree C raise, at 20 gallons of mineral oil and 200 watts of power.
It's probably moot because that's a ton of cooling surface area.
I'm surprised that the PSU and all the cables (like speaker/CAT5) work at all, I feel so uneducated.
Actually, I'd be more worried about the high-speed circuits in the machine. Oil does not conduct electricity, but that doesn't mean its electronically equivalent to air.
Oil has a dielectric constant of between 2 and 3 (depends on the oil) and that will affect the capacitance on and between the traces of the circuit-board. The signals will run a little slower on the board and have a bit more cross-talk. Its probably not a big deal -- the materials in the circuit board have a bigger effect -- but it could slow the signals enough to reduce reliability in a marginal design.
Two wrongs don't make a right, but three lefts do.
Or better yet, volumetric heat capacity...
The Good Eats episode on How To Thaw A Turkey did a great job of explaining that in layman's terms:
Cool running water melts a ice cube duck faster than a pot of water removed from the stove just as it started to boil.
"I don't know, therefore Aliens" Wafflebox1
Oil isn't even necessarily the best material to do this -- it's probably just the cheapest and easiest for a hobbiest to get hold of.
Liquid Fluorocarbon does an excellent job. The Ontario Science Centre used to have a great display of an operating television completely submurged in a small vat of the stuff. And fluorocarbon is effectively a plastic itself, and thus is harmless to plastics (unlike many oils).
Yaz.
is that every last connection has to be SOLDERED DOWN in order for this thing to work for more than half an hour.
The problem the guy ran into six years ago was that the mineral oil seeped in between all of the connections and disrupted the flow of electrons; PCI cards, AGP card, CPU, IDE, power... everything. A stock motherboard simply won't cut it, you have to have a custom board with everything hard-wired to it to survive the submersion.
This story is a dupe because it doesn't solve the basic problem.