[Beowulf] Re:running hot?

[David Mathog]

Mark Hahn <hahn at mcmaster.ca> wrote:

> are you running your machinerooms warm to save power on cooling?

How much would that really save?  Is there a study somewhere
demonstrating substantial power savings?

Whatever the steady state temperature in the room the AC still has to
pump out heat at the same rate it is generated.   Raising the room
temperature could affect heat exchange slightly because of a
steeper/shallower T gradient across the walls/floor/ceiling.  For
instance, increasing RT would let a little more power drain out through
the walls instead of the AC, assuming it is cooler outside than inside.  

Does a PC doing the same work uses more or less power at 70 or 80 degrees?

Off the top of my head I wouldn't expect a huge change in either number
for a 10 degree RT change.  Maybe it makes a big difference if the
machine room is very poorly insulated.

Regards,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech