Slightly OT: Calculating HVAC requirements for server rooms

Paul Vixie vixie at
Sun May 3 10:57:16 CDT 2009

warning-- it's sunday.  pontification alert.

"Ricky Beam" <jfbeam at> writes:

> On Sat, 02 May 2009 00:26:37 -0400, Wayne E. Bouchard <web at> wrote:
>> ... approximation
> Even an approximation is hard to make.  One might think the simple math of
> "how much power is fed into the room" would do, but it ignores numerous
> factors that greatly effect the answer.  I can rattle off example after
> example, but it's unnecessary.  You'll need professionals to install the
> hardware, so there's no point not calling them in for a consult.

"Always listen to experts.  They'll tell you what can't be done and why.
Then do it."  --Robert Heinlein

after 1993 i stopped letting HVAC people do design work for me, either at
home or at work.  i've had to sign several waiver letters promising not to
sue an HVAC company if the system they built to my spec failed to perform.
astoundingly, not everyone "in the business" knows the difference between
conduction, convection, and radiation.  consult, sure, but with suspicion.

same thing for power, structural, security, insurance, finance, network,
hardware, software, and legal people, many of whom have never questioned
their own assumptions nor those of their certification boards, state and
county governments, or teachers/mentors.  they don't have to live with the
results ... but i do ... thus my willingness to dive deep.)

Paul Vixie

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