Forum discussion
NC-2009 EAp2: Minimum Energy Performance
Greetings,
In the project we are modeling, the Proposed design has applied a chiller’s condenser heat recovery without this to be required by the prescriptive requirement (6.5.6.2).
The question is:
Should the Baseline also to apply such heat recovery and if yes, should they be identical to Proposed. Baseline is System 5.
Thanks.
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Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
June 7, 2016 - 9:52 am
See Table G3.1-11 Baseline (f). Under those circumstances are the only time it should be included in the Baseline.
It should be the identical system type but the capacities may vary a bit and therefore the savings may vary slightly as well.
Vassil Vassilev
ManagerTermoservice
13 thumbs up
June 7, 2016 - 10:07 am
Thanks for the reply.
I've read these clauses, but it stated that the Baseline should apply it if the prescriptive requires it for the Proposed.
Besides, even if we want to apply such recovery to Baseline it is not possible, because System 5 is Package rooftop, which do not have such option.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
June 7, 2016 - 10:40 am
Then apply the exception to Table G3.1-11 Baseline (f) and do not model it in either case.
Vassil Vassilev
ManagerTermoservice
13 thumbs up
June 7, 2016 - 10:49 am
Hi Marcus,
I'm not getting something.
1 How to explain to the client that his investment will not be evaluated by the model.
2. Since System 5 does not allow applying condenser heat recovery (package rooftop) why it should not be allowed for the proposed, especially when the client explicitly ordered special chillers with DHW heat recovery option.
There should be some missunderstanding.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
June 7, 2016 - 11:18 am
1. You can evaluate it in the model and show your client the benefit.
2. I don't write the rules, good question. It is probably because the code requires it under the circumstances listed. It is therefore considered standard practice here and is therefore not eligible for savings. You could try to make the case for the savings but I would submit it as an exceptional calculation. You should state (and try to prove) that it is not standard practice in Bulgaria (assuming that is the case) therefore the Baseline you are suggesting is reasonable.
Vassil Vassilev
ManagerTermoservice
13 thumbs up
June 7, 2016 - 11:31 am
Thanks for the reply Marcus,
If I understand you correctly, in the energy model I'll not model it in either case, but as an exceptional calculation I'll show the results of the designers concept and the savings from it. Of cource clearly explained and proved. This (condenser DHW recovery) is not standart practice in Bulgaria at all.
Thanks
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
June 7, 2016 - 11:48 am
You got it.
Vassil Vassilev
ManagerTermoservice
13 thumbs up
June 8, 2016 - 1:38 am
Marcus, thanks a lot for your reply and guidance.
However I think that somehow USGBC should be alert that applying G3.1-11 Baseline (f) is possible only for Systems 7 and 8, where there are chillers. Condenser heat recovert for DHW in case of Air cooled unitary is possible but theoretically, abd nobody does it in practice, so if you want to apply G3.1-11 Baseline (f) for System 5 it'll not be possible.
Thanks.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
June 9, 2016 - 10:19 am
Not including it in the Proposed model also violates one of the other modeling rule that the project must be modeled as design. So there is an internal conflict in Appendix G in that situation. So this is an ASHRAE 90.1 Appendix G issue. I have not looked to see if this has already been addressed in subsequent (2010 or 2013 or 2016) versions of Appendix G. Thanks for at least pointing it out here.
Vassil Vassilev
ManagerTermoservice
13 thumbs up
June 9, 2016 - 11:18 am
I've checked in 2013 - it is the same, without any updates.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
June 9, 2016 - 11:26 am
The 2013 addenda did not address it either. I agree that it is a conflict. At least in your case I think we found a way to address it in LEED.