Equest-users Digest, Vol 66, Issue 7

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Dear list,

I googled a bit for this problem and didn't find anything immediately so
here goes. I am working on a building that has huge computer systems that
cause 40% of kWh to go to process loads. In order to meet LEED goals the
owners went for a server/terminal solution where there is a 920W server and
19x75W terminals instead of 19x270W desktops. When I apply this as an
exceptional calculation the models go from 12 points to 20 points which
looks like it will raise flags.

My questions is:

Does this situation sound like something a reviewer would go for as an
exceptional calculation?

Do I model the baseline and proposed identically with the higher process
load or the lower one?

Thanks,
Jacob

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You'll need to be able to justify why the conventional case is the norm, and how the proposed case is "exceptional" - you might consider submitting a CIR through your project's workspace in order to solidify the details in advance.

One thing that might help justify taking credit is if the cost of the proposed configuration is more...i.e. show that the client is not taking the easier low-cost approach. If the cost of the proposed case is less, then you might explain why it isn't the default solution for the client, there must be some other trade-off involved.

If you end up claiming the exceptional calculation then the baseline and proposed will have the higher conventional computer usage rate (but with all other ECMs included in the proposed case). The exceptional calculation will be a modified proposed case with lower power usage, in addition to keepign the other ECMs.

It is possible that you end up not claiming the exceptional credit, in that case the client will still benefit by modeling the proposed and baseline cases with the lower power usage to start with, which does reflect the design intent. The project application still "gains" energy credit by having a smaller denominator for total usage, so that all of the other ECMs have a larger contribution, relatively.

I wasn't clear from your email, but it sounded like the 12 point option assumed high usage in both models. There might be an intermediate percentage where both models have lower (but equal) process usage from this computer system that results in ~13 or ~14 points as an example, without using the computer terminal energy reduction as an ECM.

David

David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP

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