[Beowulf] small cluster cooling / beer fridges

[Lux, James P]

> -----Original Message-----
> From: beowulf-bounces at beowulf.org
> [mailto:beowulf-bounces at beowulf.org] On Behalf Of Mark Kosmowski
> Sent: Thursday, September 18, 2008 12:19 PM
> To: beowulf at beowulf.org
> Subject: [Beowulf] small cluster cooling / beer fridges
>
> >
> > Questions (same RGB asked):
> > What environmental conditions should such an office have?
> > 1.5ton A/C?
> > 4kW  capable wiring?
> > Beer keg refrigerator?
> > How many air vent and drip holes on the walls, ceiling and windows?
> >
> Assuming the physical dimensions work, would condensation (or anything
> else) be a problem if someone, say a crazy grad student in
> his non-AC basement, were to put a few desktop nodes in a
> used, cleaned refrigerator?

No big problem.  The condensation will tend to be on the cold coils. However, refrigerators don't move very much heat though. A 100W lightbulb would probably overpower the refrigeration capacity.  They're also optimized for a delta T of 30-40 degrees F (i.e. keep the insides at 40 when the room is at 75)

If you're buying, you're much better off getting a small airconditioner, especially one of the ones that has a hot air outlet duct you can shove in a window.  Even small $100 room A/Cs move 5000 BTU/hr (1000 BTU is 1054 kJ... A 200W PC is dissipating 720 kJ/hr.. So a 5000 BTU/hr unit will just keep up with a 1kW load).  Even better would be a "mini split" AC, which puts the hot part outside, but they're pretty pricey.  The room AC is optimized for a smaller delta T, though.



 For power into the fridge, a
> hole could be drilled into the hull and then filled in with
> closed cell foam once the cords are poked through.

Careful there.. They run wires and pipes in the walls, particularly on those 2-4 cu ft "dorm refrigerators"  and kegerators.  I did my part contributing to global warming by not knowing this.  A better solution is to cut a slit/notch in the door gasket.  The door is also usually less likely to have critical components imbedded in it.