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Silent Pump for Water-Cooled PCs
Wycliffe writes "New Scientist has an article about a silent pump for water-cooled PCs.
The system, developed by a Californian start-up company, aims to silently solve the problem that the faster chips get, the hotter they become."
While they say it pushes 200mL/min, they don't say how much power it requires to do so... peltiers are incredibly effective, but suck an obscene amount of power to do so.
If this new pump requires 75W or more, then you're unlikely to win in the long run - you'll just need a bigger PSU (and bigger, noisier fan in it) to get the job done.
Anyone have any more detailed links?
Using a stiring engine for heat recovery would likely be counter productive as your cold sink is too small to help drive the engine, this is the cooling problem you are trying to solve in the first place with the chip not cooling enough.
The drawback is to get the efficiency at that small of a scale, the cost will be fairly high. The engines can be made small enough, but for a price probably far too high for the general market. Say about $2,500 each. Then you have to shield the rest of the computer from the NeFeB linear motor/oscillator magnets used to drive the engine in reverse. Another thing is the drawback that thay are probably shock sensitive. So a good whack could cost a fortune to the average pocket book.
Once you comprimise the efficiency to the point of about say 8%, you might as well just give up on the stirling idea and go with a Peltier device since they are solid state and fairly cheap (20$~100$) and already off the shelf.
The high efficiency capabilities of the stirling engine are about the only reason you would want to use one in the first place, so the option is really not available it would seem for a cost effective and mass produced market.
I am very tired of idiots who post about being worried about water near electricity, rust, you name it. I think it shows how basic science education is being neglected. So I would like to make a few points.
Pure water is a poor conductor of electricity. That's why ordinary condensation caused by the lowering temperature of humid air rarely causes problems with electrical equipment. The conductivity of good quality DI or distilled water is actually not high enough to affect most digital systems. It wouldn't be good if it got into rotating components, but in the low-resistance 5-12VDC environment, a little damp is not a problem.
Furthermore, in the absence of dissolved air, water does not promote rust. Generations of science teachers have shown kids that iron nails in distilled water stay bright while those in aerated tap water rapidly rust.
The biggest problem I am aware of with water cooled electronics - and I have been involved on and off with liquid handling since 1980 - is inappropriate choice of materials. The common polyamide (nylon) pipe is water absorbent, as are some other widely used polymers. Cast metals are also often prone to porosity, pinholes and slag inclusions, which can be major sources of leaks. Pressure testing is a good idea.
Another problem with water cooling for electronics is inappropriate design of connections, resulting in too much mechanical load either on the connection itself, sealing faces of pumps, or the attachment of the cooling plate to the substrate.
Unlike automotive cooling, vibration is not usually a major problem.
This isn't a howto essay, but here are a few pointers.
DO NOT EVER use automotive components. They are designed for robustness and can handle high levels of sludge, and in any case are designed for use with glycol mixtures.
DO NOT create high pressures. The object should be to have wide flow paths working at low pressure differentials with minimum turbulence. I'm amazed when I read descriptions of heat removers describing them has having internal passages designed to promote turbulence - because turbulence is bad. You want, ideally, laminar flow across the hotspot so that it is in contact with a constantly changing flow of cold water.
Platinum cured silicone tubing is very good. It contains no cure residues that could make the water acid and it is very flexible. It needs to be carefully routed to prevent kinking but it puts low stresss on joints.
Flow back to header tanks should avoid bubbling to prevent aeration, and header tanks should be covered except for a minute hole (filtered) for pressure compensation. If you can keep spores and bugs out of the water, you will not grow algae.
Ideally all metal parts should be the same metal or at least metals of similar electrochemical potential.
Use lab grade DI water.
Use compression joints rather than just relying on the elasticity of the pipe.
NEC has said they are working on a system designed to eliminate leaks - their curious reference to "resin" being, I suspect, a reference to epoxy or nylon components that are prone to leak slowly. The automotive industry has done it: liquid cooled auto engines now require hardly any maintenance of the cooling system. I'm sure that once the serious manufacturers get on the case and the amateurs start to fade into the background, liquid cooling for personal computers should come on rapidly, for all the same reason as automotives (more power in smaller space, more accurate temperature control, able to reach less accessible places, smaller block mass needed for heat exchangers). The technologies are all there, the need is obvious.
Panurge has posted for the last time. Thanks for the positive moderations.