I'm funneling this question on behalf my mechanical engineer:
Our total breakdown of energy use is as follows:
Total energy use all forms: 543 E10^6 Btu/yr
Lighting: 253 E10^6 Btu/yr = 46%
Space Heating: 212 E10^6 Btu/yr = 39%
Fans – Conditioned Space: 63 E10^6 Btu/yr = 12%
Is it correct to say that if we meter the mains and then report these three sub-meters the credit has been satisfied? The remaining fractions of energy consumption are less than 10%. The key question is whether the reviewer will expect the larger components say lighting to be sub-metered to the 10% threshold. I’m not even sure how we would do that. I can’t predict how long someone is going to leave the lights on!
Any thoughts?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5867 thumbs up
October 6, 2017 - 10:46 am
That sounds correct.
Actually you can predict how long the lights are going to be on and are basically required to do so. What you can't ensure is that your prediction will be accurate when compared to the actual operations.
I am not sure what your key question means, specifically the part about submetering to the 10% threshold? Basically you create your energy model using the best available information and a modeler who is experienced with producing relatively accurate results. You then generate those results. Any energy end use that is over 10% of the total energy use must be submetered. If an end use is close to 10% it may be a good idea to also submeter it because the energy modeling results often change during the review process. If an end use goes over 10% as a result of that process then you would no longer be in compliance with the requirements of this credit.