IBM Pushing Water-Cooled Servers, Meeting Resistance

judgecorp writes "IBM has said that water-cooled servers could become the norm in ten years. The company has lately been promoting wider user of the forty-year-old mainframe technology (e.g., here's a piece from April 2008), which allows faster clock speeds and higher processing power. But IBM now says water cooling is greener and more efficient, because it delivers waste heat in a form that's easier to re-use. They estimate that water can be up to 4,000 times more effective in cooling computer systems than air. However, most new data center designs tend to take the opposite approach, running warmer, and using free-air cooling to expend less energy in the first place. For instance, Dutch engineer Imtech sees no need for water cooling in its new multi-story approach which reduces piping and saves waste."

Comments

Ratio of specific heat capacities

[NCamero]

All IBM is saying is that water is a better heat conductor, and air is an insulator.

http://en.wikipedia.org/wiki/Specific_heat_capacity

Water ; 4 J /cm^3 K
Air ; 0.001 J /cm^3 K

Water/Air = 4000 times more heat transfer.

So, given the choice, you would use water to transfer heat.

Re:Ratio of specific heat capacities

[Aceticon]

My personal experience with using passive (no fans) water-cooling with my desktop PC at home (the setup is similar to this: http://www.silent.se/bilder/reserator1_c_p-410.jpg) is that that it's exceptionally effective.

In my setup a cylinder full of water surrounded by fins to dissipate the heat and with a pump to make water flow as the only active element have replaced a big nasty CPU heatsink with a large fan (on a heavily overclocked CPU)* and a set of fans on a single high-end graphics card of the previous generation. At an ambient temperature in the room where this is in of about 20-25C The whole thing idles at 28C and stays at around 60C with everything going on at max - considering that with everything going on at full throttle the system is using almost 400W, it's impressive how efficient it all is.

In practice, "home" water-cooling mostly just uses the water as a heat carrier to quickly move the heat around from the inside of the computer case (and it's constrained airflow) to a place where it is easier to dissipate that heat into the ambient air either with a more efficient radiator and fans (for the active systems) or with an outsized heatsink (like the one I use which has roughly 10 times the surface of the ones it replaces).

In an "industrial" deployment, said heat being carried in the water cold potentially be used/dissipated in many more ways. For example large pipes could transport the hot water coming out of a data-center to the sea or a river and let it be dissipated there (keeping a closed circuit and returning the cool water back for reuse). The actual running costs in terms of active elements for such a system are limited to the cost of running a number of large efficient water pumps that make the water flow around the circuite as opposed to most data-centers out there at the moment that use (less efficient) small fans to move the air out of the blade boxes into the room and then active refrigeration to cool down the air in the room.

* Since the point of my argument is not to show off my "virtual dick", I've moved the relevant stats down here for those that are curious on the details: CPU - Core 2 Quad 2.4 GHz which is overclocked to 3.2GHz, GPU - GTS280

Re:I watercooled my server years ago!!!

[jcr]

Try to keep up IBM.

IBM was water-cooling machines at least as early as the 1970s.

-jcr

Re:When I come to office today

[miffo.swe]

Problems with crystals comes with some types of water where there are a high degree of lime in it. While its simpler to just use heat exchangers you could also use waterfilters that separates the minerals from the water before use. Most places have water with low amounts of lime and minerals so deposits arent really a problem.

I had a company that made solar panels (heating houses) and inverters for house warming. In some cases we took ground water and extracted heat directly from it and when taken apart those heat exchangers very rarely showed any deposits at all even after ten years of use.

The easiest way to see what type of water you have is to look in your toilet and your sink. If there are much deposits there (not brown ones) you have water thats high with lime or other minerals.