Computer Room Cooling 1

[ChrisConley]

Hello all,

I'm looking at providing some dedicated cooling to a computer room, for a call center. The room is around 245ft2 and has one exterior wall. I was given a list of computer equipment and their associated heat gains into the room, and the number supplied was 15 tons of cooling.

Now I don't pretend to know everything about heat rejection from computer equipment, but I suspect that the information I received was the power supplied to the equipment, not the heat rejected by the equipment. For example one of their switches is rated at 3600W (12,000 Btu/hr) of heat rejection, I can't see single switch rejecting that much heat, am I wrong?

What are the factors commonly used to convert name plate power consumption of computer equipment into heat rejection? Can anyone suggest a system that allows for cooling a computer room (DX cooling), but allows the heat to be used in the rest of the building during the winter?

Thanks all,

And Happy Holidays to those celebrating at this time of year.

 

[wilg]

You are correct in assuming that they are giving you name plate information that is going to lead to oversizing of the equipment. My experience is that about 30% of the
name plate when it comes to computer equipment is a good estimate.Take a printer for example, at rest it's hardly
using any power, however when it's operating it can be using up to 75% of it's name plate rating, use a diversity use factor and estimate a printers actual time that it's being used. ASHRAE journal magazine printed a good article in Sept. 1991 on an analysis of office equipment load factors.As for the second part of your question:
install two condensors, one outside for summer use and
one indoors for winter use, that way you acn use the heat of rejection from the condenser during the winter months.