Hi Mark, check out the Iceotope website of how they are doing it: http://www.iceotope.com/
They are only using convection and the mother board is mounted upright as opposed to be the more convential horizontal mounting. Also, they don't cool the board to 20 °C but have it more or less at a higher temperature. Here the used Nova has a low viscosity and moves well as far as I understand it. There is still a chilled plate (one side of the aluminium container) which removes the heat. The AC in that data-centres is a complete and utterly wrongly installed system done my AC specialist. Sucking off hot air at the bottom is never a good idea and blowing in cold air parallel to the racks with a high wind speed does not help either. I got hotspots in the room and if one unit fails I can run into a problem very easily. So yes, that number of 2 might be high but in my case it is most likely more the correct number. All the best from London! Jörg P.S. I am not working for Iceotope! On Donnerstag 28 Februar 2013 Mark Hahn wrote: > > consumption from 41 kW (electricity, probably same amount again for > > cooling) > > I really doubt it. there is something profoundly wrong if an > HPC-type datacenter, with completely conventional servers, air/DX cooling > runs at a PUE of more than about 1.3-1.4. > > immersion cooling sounds appealingly unconventional, but if you think > about the heatflow, you've still got to move it around. you still need > a heatsink on the CPU with fins, some way to move the fluid past these > fins and get them to the secondary heat exchanger. as with airflow > management in a conventional DC, surely one has to ensure that cool > fluid gets to the CPU fins and heated fluid finds its way to the > rejection exchanger. surely convection wouldn't be good enough without > some serious re-engineering. or do these systems rely on boiling? > > so I wonder what the effective thermal resistance is for such a > fluid system (assuming some fishtank-like pumping). risk-wise, > I'm pretty sure I'd be more comfortable with a heatpipe inside > the chassis mating to a coldplate/exchanger built into the rack > running the water loop. > _______________________________________________ > Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf -- ************************************************************* Jörg Saßmannshausen University College London Department of Chemistry Gordon Street London WC1H 0AJ email: j.sassmannshau...@ucl.ac.uk web: http://sassy.formativ.net Please avoid sending me Word or PowerPoint attachments. See http://www.gnu.org/philosophy/no-word-attachments.html _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
