

Supercomputer uses warm water to cool its servers and heat its building - ph0rque
http://www.nrel.gov/news/features/feature_detail.cfm/feature_id=15403

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IvyMike
I used to work with water-cooled test equipment.

One thing that surprised me was that the water _was_ warm. The reason I was
given was that had chilled water been used, you would have all sorts of issues
with condensation. So instead of cooling the system with cold water, you
cooled by pumping in lots of room-temperature water. The next effect: the same
amount of heat is pulled out.

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joezydeco
How does the volume of water needed differ from the ambient temp vs the
chilled temp?

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bengali3
per the chart here [1], it appears that a given volume of 40 degree(F) water
is 0.03% smaller than that of 80 degree water.

[1] [http://www.engineeringtoolbox.com/water-specific-volume-
weig...](http://www.engineeringtoolbox.com/water-specific-volume-weight-
d_661.html)

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joezydeco
My question was more about how much _more_ water is needed to absorb the same
amount of energy from the server.

If the water pumping into the server is 20-30 degrees (C) hotter than chilled
water, it can't absorb as much heat energy from the server before turning to
steam. So you need to transport more water through the same system to keep the
cooling effect the same.

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IvyMike
I was the software guy, and I have to admit I weaseled out of taking a thermo
class in college, so unfortunately I don't have an answer for you.

