I'm interested in what people think is the right way to treat this scenario for LEED/Appendix G, I could see it going either way :
Climate zone 5a, District Cooling plant, using option 1 (stand alone bldg), but the central cooling plant shuts down between Nov 1 and Mar 1. For the baseline, do I :
a) Use a district chilled water meter all year.
b) Use a district chilled water meter all year, but match the proposed sequence and shut down during the winter
c) Shut down in the winter, but provide the non-DES cooling system for that period.
I'm leaning towards A, since the economizer should handle almost all the loads, but there is the part in App G where they talk about heating and cooling must be available in the building.
Bonus:
For the IT loads, there are WSHPs on a drycooler loop, since CHW is not available year round. Do I use:
a) District chilled water all year,
b) Shut down chilled water in the winter, but provide the non-DES cooling system for that period.
Leaning towards B on this one. Seems more "fair" since there is a significant cooling load year round but the primary cooling source (CHW) is not available year round. I see it similar to the schedules that differ for more than 40 hours per week exception.
The kicker is that because they are IT units, their performance on a glycol loops is less than stellar compared to the air cooled baseline system.
Let me know you think.
Brendan Hall, PE, LEED AP BD+C
Engineer, Mechanical
karpinski
ENGINEERING
3135 Euclid Avenue
Cleveland, OH 44115
P 216.391.3700
E bhall at karpinskieng.com
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