Slightly OT: Calculating HVAC requirements for server rooms

joel.mercado at verizon.net joel.mercado at verizon.net
Sat May 2 08:50:09 CDT 2009


   Just knowing your spacing and were to places perforated tiles is very
   helpful in maxmizing air and not shortcycling it..

   Establishing a Floor Plan

   [1]http://www.apcmedia.com/salestools/VAVR-6KYMZ7_R0_EN.pdf
   May 2, 2009 08:41:50 AM, [2]alex at corp.nac.net wrote:

     Calculating heat load in a datacenter is pretty easy. That's not the
     hard part.
     Some comments:
     > I am curious what formulas/equations folks use to figure out
     required
     > cooling for small datacenters in offices.
     The simplest equation to use assumes that you know how much power is
     going into the room.
     Btu/hr = watts * 3.412
     This further assumes that a typical IT load is very inefficient
     (which they are).. meaning that, for every watt that goes to a
     computer / server / router, a significant portion is converted to
     heat (we assume 100% for design purposes).
     So, if you have a datacenter consuming 100kw, you'd need 341,200
     btu/hr of cooling, or 28 tons of HVAC. Of course, there are other
     issues (like leakage, windows, doors, humans, lights) but these tend
     to be a little bit of line noise in a modern datacenter. Also
     outside environment (is this Quebec or is this Cuba), insulation,
     design delivery temperature, humidity requirements -- all play a
     part.
     > Translation: Hire a f***ing professional.
     >
     > And that's exactly what you need to do. Qualified HVAC installers
     Two comments on this... first of all, the last thing you want is an
     HVAC 'installer' to design your HVAC system in a datacenter.
     Secondly, if you find an HVAC engineer who *really* knows datacenter
     dynamics, that could be a help. But, frankly, there aren't a lot of
     them.
     If you need some help with this, let me know. There are a
     significant amount of questions that need to be asked to give a
     qualified answer. The cooling capacity question is secondary to the
     delivery and extraction method.
     I also submit that any good datacenter operator, who has had years
     of experience of trial and error, years of engineers who say they
     know something and don't, and had scores of contractors who say they
     know something and don't, is in a much better position to talk about
     this than a PE who designs comfort cooling systems.
     "Question everything, assume nothing, discuss all, and resolve
     quickly."
     -- Alex Rubenstein, AR97, K2AHR, [3]alex at nac.net, latency, Al Reuben
     --
     -- Net Access Corporation, 800-NET-ME-36, [4]http://www.nac.net --

References

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   1. http://www.apcmedia.com/salestools/VAVR-6KYMZ7_R0_EN.pdf
   2. mailto:alex at corp.nac.net
   3. mailto:alex at nac.net
   4. http://www.nac.net/

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