Re: DATACENTER: Datacenter HVAC requirements

[Robert Szarka <szarka@downcity.net>]

At 07:36 PM 6/14/99 , Mark Smith wrote:
>
>Ok, so if I look in my cool little master converter program it tells me
>that 1 watt = 3.4120962 BTU/hr. So my questions is how much cooling do

Actually, the rule of thumb I've seen is 1 watt = 3.5-3.7 BTU/hr.

>I need for my datacenter? Is it as simple as:
>
># racks * 20 amps a rack * 3.4120962 / 12,000 (BTUs in a ton) = tons of
>HVAC required?

But an amp isn't a watt!  It's been a couple of years, but I think since
Ohm's Law gives P = I x E (power = current x voltage), and assuming 120
volts, you get something on the order of 2.4 kva if the circuit were fully
loaded.  So if your hypothetical rack on a 20 amp circuit were generating
2.2 kva you'd need something on the order of .7 tons of cooling per rack.
Now, I am definitely *not* the HVAC guy (or the electrical engineer) here,
so that could be way off, but that's how it looks to me.

Of course, a quick peek says my server room is sucking up only a little
over a kilowatt right now, so if you have more routers than hard drives in
that rack, I'd guess you'd be overbuying cooling quite a bit.  Given the
weather, that doesn't seem like a bad thing, but...  :)


-- 

Robert Szarka
Managing Partner, Operations
DownCity, LLC
+1 860 823 3000