[rescue] Deciding how to place machines in a rack...

[Patrick Finnegan]

On Wednesday 05 March 2008, Earl Baugh wrote:
> I'll space each machine 1U apart, but I have a question regarding
> that.

FWIW, I'd suggest making the machines as contiguous as possible, 
especially if you're going to used forced airflow (you mentioned a fan 
at the top of the rack), and make sure that you cover all of the unused 
U of rackspace.   If I were doing this, I'd either use pieces of metal 
that I found being thrown out, which worked, or cardboard, which works 
just as effectively (and if painted, even looks ok) as the blanking 
panels that you can spend a few $$ apiece.

Spacing the machines apart will only serve to make "dead" air zones 
which act as thermal insulators... if the cases are close to each other 
(or touching), any one warm system would conduct heat to other cooler 
systems, which should help even out temperatures... but in any case, 
rackmount computers shouldn't be using the case as a heatsink (though I 
have seen it done with A/V equipment).

One other thing I'd add, using a rack with a plexiglass front door, and 
putting any more than a couple hundred watts worth of gear in it is 
probably a really bad idea.  I think someone else mentioned that you 
had a plexiglass door... I'd suggest replacing the plexi with a piece 
of perforated metal of some sort.  Window screening would probably work 
just fine for home use, and should be relatively cheap to pick up.

Just my $2. :)

Pat
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