North American Network Operators Group

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Re: cooling door

  • From: John Curran
  • Date: Sat Mar 29 16:27:32 2008

At 7:06 PM +0000 3/29/08, Paul Vixie wrote:
> > While the chilled water door will provide higher equipment
>> density per rack, it relies on water piping back to a "Cooling
>> Distribution Unit" (CDU) which is in the corner sitting by your
>> CRAC/CRAH units.
>it just has to sit near the chilled water that moves the heat to
>the roof.  that usually means CRAC-adjacency but other arrangements
>are possible.

When one of the many CRAC units decides to fail in an air-cooled
environment, another one starts up and everything is fine.   The
nominal worse case leaves the failed CRAC unit as a potential air
pressure leakage source for the raised-floor and/or ductwork, but
that's about it.

Chilled water to the rack implies multiple CDU's with a colorful
hose and valve system within the computer room (effectively a
miniature version of the facility chilled water loop).  Trying to
eliminate potential failure modes in that setup will be quite the
adventure, which depending on your availability target may be
a non-issue or a great reason to consider moving to new space.