[Bldg-sim] Precision Cooler - Big Disadvantage in Comparison to Baseline?

[omoltay at mimtarch.com]

Dear All,

My proposed model includes a 250 sq.ft. server room with 11,44 kw of
installed equipment (nameplate power). I assume that these will be running
24/7/365 with full power and giving away 100% sensible heat (noting these
to get your reactions on my assumptions as well).

This space is cooled by a 25 kW precision cooler with a COP of "1". With
such performance, this is a big time loser against what I am modeling for
the same space in the baseline with System 3. Actually, the SSH report
tells me that the precision cooler is using 90000 kWh p.a. for cooling
compared to 32600 kWh in the baseline model. However, we all know that in
real life such systems will never be used for server rooms.

Isn't this unfair? I am still considering whether this cooling energy
should be part of the process energy. There is actually a CIR from 2003:

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4/11/2003 -  Credit Interpretation Request
Kelley Engineering Center is in design as a 144,000 s.f. university
research and teaching building. This project includes a 2200 s.f. data
center with racks of servers, and a uninterruptible power supply room.
This area has dedicated cooling equipment to extract the heat produced by
all of the electronics. Given the nature of the space, and the purpose of
the cooling equipment, it appears to meet the definition of a process
load, and can be excluded under ASHRAE 90.1 from the energy cost budget
for this credit. Do you agree with this interpretation?

5/5/2003 -  Ruling
Yes, as described the dedicated server room air conditioning equipment
fits the ASHRAE 90.1-1999 definition of "process load." As such it can be
excluded from the project's Energy Cost Budget.
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What do you think about this? What are your experiences with server room
air conditioning and modelling for LEED?

Thanks for all the answers and happy weekend,

Omer Moltay, LEED AP
Mimta Ltd.