On Fri, 01 May 2009 21:32:19 -0400, William Warren
<hescomins...@emmanuelcomputerconsulting.com> wrote:
Specifically, I am using the guide posted at:
http://www.openxtra.co.uk/articles/calculating-heat-load
"Before you decide on an air conditioning unit you should commission an
audit from a suitably qualified air conditioning equipment specialist or
installer."
Translation: Hire a f***ing professional.
And that's exactly what you need to do. Qualified HVAC installers (with
specific data center experience) will know far more than us "network
types" will ever want to know about cooling. They do this for a living,
and thus, know all the tiny details and odd edge cases to look for. (like
looking above the drop ceiling -- that's what it's called, btw -- and
seeing what's up there long before pencil meets paper (not that anyone
uses paper anymore.))
You also have to take into account the environment surrounding the data
room. At my wife's work The ceiling above is only separated with a
false ceiling to the metal roof above but the rest of hte spaces
surrounding the room are climate controled. They [had] to significantly
upsize to account for the heat load of that ceiling.
Unless you are pulling air through the plenum (that space above the drop
ceiling), the air up there shouldn't matter much -- there should be plenum
returns up there to begin with venting the air to the surrounding
plenum(s) (i.e. the rest of the office, hallway, neighboring office,
etc.) However, I've seen more than enough office setups where the
"engineers" planning the space completely ignore the plenum. In my
current office building the static pressure pushes the bathroom doors open
by almost 2". And they placed our server room directly under the building
air handlers -- meaning all the air on the 3rd floor eventually passes
through the plenum above my servers. (also, the sprinkler system riser
room is in there.)
Bottom line, again, ask a professional. NANOG is a bunch of network geeks
(in theory.) I'd be surprised if there's even one licensed HVAC "geek" on
the list. ('tho I'm sure many may *know* an HVAC engineer.)
--Ricky
