high physical density cluster design

[pbn2au]

>
> Problem 2 - Heat Dissipation
> """"""""""""""""""""""""""""
> The other problem we're going to have is heat. We're going to need to build
> our cabinet such that its relatively sealed, except at front, so we can get
> some coherent airflow in between boards. I am thinking we're going to need to
> mount extra fans on the back (this is going to make the 2x2 design a bit more
> tricky, but at only 64 odd machines we can go with 2x1 config instead, 2
> stacks of 32, just 16U high). I dont know what you can suggest here, its all
> going to depend on physical configuration. The machine is housed in a proper
> environment (Datavaults.com's facilities, where I work :) thats climate
> controlled, but the inside of the cabinet will still need massive airflow,
> even with the room at 68F.

    For this much heat, I am not sure that you should not rethink this whole Idea. Some suggestions( not tongue in cheek) : Have you considered a
refrigeration unit? Put it in a walk-in freezer and go from there. Another option will be to build a sealed water tight box and encase the boards
in chilled mineral oil. The conductivity of the oil is legendary, and nonexistent. use a small unit to chill one end, and a couple of stirring
units to keep it circulating. The biggest issue is not heat within the unit but the effect on other units in the same room.