CPU Cooling with 15 Liters of Water

ninjagin writes "While not an OC-er, I do enjoy reading about the lengths people will go to on their way to a better CPU cooling solution. I ran across this very interesting article at overclockers.com about this guy's immense 15-liter water cooling rig for his home office PC. Might be just the kind of thing to have the contractors include when they pour your next garage slab."

Comments

The Problem with water Cooling

[Michael's a Jerk!]

I've been thinking of mking a rig like this, but there are reliability problems. Check out What Happened to Dan of Dan's Data.

Corrosion is a big problem for the uninitiated :-(

Re:The Problem with water Cooling

[Michael's a Jerk!]

Ah, did you read the referenced article?

Basically, his hear exchanger was the annode in an unintentional battery :-)

The copper corrodes a little, as copper in water or air always will. This is not normally a big deal, because a thin copper oxide layer forms and protects the rest of the metal. But in the process, some copper ions go into solution and make their way around, thanks to the pump, to the aluminium water block. They precipitate onto the water block surface as teeny little metallic copper particles.

And then plain old galvanic corrosion can happen, as the copper and aluminium are in physical, and thus electrical, contact, and both immersed in the electrolyte. The dreck you end up with is mainly aluminium oxide, with its greenish colour donated by a light lacing of copper oxide. Tah-dah.

When I flame-tested some of the precipitate, by the way, this was borne out; green flame from the copper, bright sparks from the aluminium. Case closed.

Incidentally, when I was trying to track down information on this subject, I discovered that if you start searching for "galvanic corrosion" in the company of some other computer-cooling-relevant words, you're likely to find a large number of pages belonging to homebrew enthusiasts, and a smaller number of pages belonging to nuclear reactor technicians.

Neither of these groups of people want galvanic corrosion to happen in their equipment, but judging by the degree of unhappiness expressed by those who have had equipment destroyed by it, it would appear to be much more irritating when it ruins a batch of beer than when it results in radioactive liquid sodium spraying all over a control room.

Re:The Problem with water Cooling

[palutke]

Using a copper waterblock instead of aluminum helps prevent this, as does using some sort of additive to inhibit the corrosion (water wetter or a little anitfreeze).

15 liters is nothing..

[Lord Fren]

I cool my PC with my outdoor swimming pool!!

Still having problems with dirt clogging the lines though. .
On the plus side, when that happens I get a nice introduction fusion when my Athlon melts down!

Current PCs and noise

[Simon Kongshoj]

Am I the only one who thinks it's absurd that there even is a need for something like this for reducing noise in current computers? I mean, I could understand it if the guy was some compulsive tinkerer who overclocks everything in sight, but for silence in a home office PC?! It seems insane.

I sometimes think that, for those of us who don't play the latest games anyway, PC's are becoming too powerful for their own good. Most current PCs have a large pile of case fans, a big noisy CPU fan, two fans in the power supply (sometimes very noisy, sometimes not), a small and very noisy fan on the graphics card, and another one on the chipset. I've seen mods that add fans to RAM, although those are still only needed by overclockers.

Re:Current PCs and noise

[Sycraft-fu]

Oh I perfectly well understand the desire to reduce noise from a PC. My current PC has a cheap case fan and power supply and can charatibly be escribed as a jetplane. It rather annoys me.

However, as you allude to, his solution is not necessiarly the best nor the most ecenomical. For myself, I have ordered a new power supply and case fan. Total cost is about $110 with shipping. Now provided the information on these units is accurate, it should cut the fan noise to a level such that the vibrational noise of the harddrives becomes a bigger concern.

This is generally a much more cost effective solution and also a more practical one, as you don't tie your computer to one location. Just locate good, quite fans from a company like Papst. Then, find a powersupply that has been made for silence. A number of companies take powersupplies from companies like Sparkle and upgrade them with better fans and more efficient electronics to give better sonic results. You can also find some powersupplies that are totally silent, they operate only with a large heatsink, no fan at all.

All in all, if you took a fanless VGA cooler like the Zalman ZM80A (rated for GEForce 4 class cards), a silent powersupply, a quiet CPU cooler and one quiet case fan it would be easy to have a high performacne system with fan noise under 20dB at 1 metre. At that point your harddrives would be a hard larger problem, which water cooling does not help.

Re:huh?

[RPI Geek]

If you're not overclocking why even bother?

Because he can.
Because by putting this on the internet, now someone else can who may not have been able to before.
Because of the joy of building something.
Because it's quieter now.

Bend allowance

[BenjyD]

When the system was finally completed, the flow rate was tested and determined to be 3L/minute.

I'd guess that his estimate of the flow rate was off because his pressure drop calculations assume a straight pipe - they make no allowance for the effect of the multiple 90 degree elbows in his radiator.

Re:Why water ?

[BenjyD]

Many cooling systems do use oils instead of water. No cooling oil I've ever seen (Dowtherms etc.) can compare to water for heat transfer efficiency. Water has low viscosity, high heat capacity and is cheap.

The only liquid that really does much better is mercury, not something I would want flowing round my computer.

just 15?

[jesler]

Why use 15 litres when you can use 15 BILLION litres???
br. I plan to live in a houseboat and tow my submerged boxen.

My variant

[skroz]

Now that's just damn creepy... I was thinking about doing something very similar just yesterday. I'll be building a house soon, and was thinking about what I'd do if I could build a cooling system directly into the house. The idea I came up with is similar to this one, but I think I have some improvements.

The garage floor is at ground level, and concrete is an AWFUL conductor of heat. This presents two points of inefficiency; the temperature of the concrete will be affected by seasonal temperatures due to air temperature and proximity to heated surface earth along the edges. Depending on what part of the country you're in, the ground temperature below 24-36 inches is a constant temperature in the low sixties or upper fifties. SO, while the base of the garage floor's foundation is likely below this point of constant temperature, the poor conductivity of the concrete will likely render the system far less efficient than it could have been.

My server closet would be in the basement, preferably with the systems close to the ground. The system I envisioned is identical to his up until the heat exchanger. Rather than dumping heat straight to the concrete floor, I thought of getting a 18" x 18" steel plate and welding 1" thick, 24" long iron bars to it, perpendicular to the surface of the plate. 16 bars should do. You then sink the bars through holes in the wall straigt into the earth as close to the floor as possible, resulting in the deepest possible depth for the bars. Your heat is then dumped to the very cold, constantly cooled earth at a depth of anywhere from four to five feet.

On a practicality scale of 0 to 10, 10 being as practical as brushing your teeth and 0 being as practical as replacing your teeth with screw-on ceramic chompers that you can toss in the dishwasher, I give this solution about a two. Nobody in their right mind is going to go to all of that trouble to cool a few CPUs. Or drill holes in their foundation, for that matter. But it would still be cool. ;)