I'm trying to come up with some rule-of-thumb cooling
> requirements to help folks in determining appropriate
> conditions for installations. I'd like to come up
> with something similar to how combustion relief requirements
> are specified (CuFt per BTU).
>
> Of course, this would be complicated by ambient temps
> as well as the temperature of replenishing air.
>
> Ideally, three sets of criteria:
> - no additional cooling required
> - nominal ventilation required
> - refrigeration required
>
> Data centers do this but on a much larger scale (and similarly
> upsized cost).
>
> Any pointers to some general rules of thumb -- especially
> for enclosed spaces (I realize most people don't even think
> about such things in their designs -- "if the ventilation
> is inadequate, the system doesn't work; plan accordingly
> when you make your purchase!")
It's extremely straightforward. You need to know the amount of heat you are generating, the heat-dissipating capacity of the scheme you have adopted to get rid of it, and the heat dissipating capacity of the area into which you dump the heat.
That doesn't mean that it is easy to do. As one colleague once pointed out, a set of black anodised heat sinks on the back of an amplifier can generate a lot of convective air flow, but if you put the amplifier on a sunny window-sill close to a pane of glass, you don't get as much convection as you might in a less confine space and the sun shining on the heat sink adds to the heat you need to dissipate.