I can see in the threads some discussion about submeters and what really constitutes complying with Case 1 but I'm still confused. Our understanding has always been that a house meter for energy and a water meter will suffice for this credit for less than 75% occupancy.
However, I've received a comment that indicates that process water MUST be submetered to comply. So first of all, this is an energy credit about submetering and yet multiple energy sources can be combined in one meter but water cannot? Secondly, this project is a restaurant so the non-process water use is actually negligible. So we'd have to separately meter restrooms to comply with the credit? That seems onerous and unreasonable and the value of these metrics would be really questionable. I could understand this in Case 2 where all the end uses come into play but not in Case 1.
So we have three meters - electric, gas and water - and we can't comply?
Can anyone provide insight into this?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
December 19, 2012 - 9:50 am
I do not believe that multiple energy sources can be combined into one meter. Each energy source must have a meter. Perhaps you meant energy uses.
I agree that a single water meter should suffice for this credit as no submetering is required within the tenant space. If all of your energy and water use is accounted for with the three meters it sounds like you would comply to me.
Michelle Rosenberger
PartnerArchEcology
522 thumbs up
December 19, 2012 - 11:38 am
Hi Marcus,
Thanks for the response. Yes, I did mean electrical energy uses can be combined, thanks. And that's what we thought, also. But my reviewer is saying that "electrity and fossil fuel for process uses (other than plug loads) and the process water consumption must be separately submetered".
The reference guide says "install submetering equipment to measure and record ENERGY use with the tenant space". Then in the text of pg 191 says "Water used for the convenience of occupants does not need to be submetered. This includes restrooms, changing facilities, water fountains, breakrooms and janitorial uses". However Table 2 right below that statement indicates that process uses including water, electric and fuels is a Yes in the required to be submetered column.
Since the only way to isolate process water use would be to submeter the restrooms, that seems to be in conflict. I will try and push back on the comment and see what happens. I'll post the results. Thanks.
Carolina Acevedo
Designer, Sustainability Department3 thumbs up
December 19, 2012 - 11:48 am
Hi Michelle,
I've been looking at this credit (it has very confusing syntax) and I think what you might not understand is that "process water" in this case is not water used in the restrooms: it refers to water used to provide energy. This would refer to chilled water from a cooling tower, used for an HVAC system, for instance, or water used for industrial processes. The intent is to understand energy consumption from all different sources of energy.
I don't entirely understand how one would submeter water from a closed-loop cooling tower (this is my dilemma at the moment), but apparently there are ways to know how much energy you are using (in cooling) from a cooling tower.
Michelle Rosenberger
PartnerArchEcology
522 thumbs up
December 19, 2012 - 11:54 am
Hi Carolina,
I certainly am confused and that might be why. I will say though that the Table 2 Submetering requirements lists water in the Heating and Cooling categories which would speak to your comment. But then also lists service water and process water separately.
We are a restaurant with many appliances and equipment that use water. When we do ID credits for process water savings on other projects, we focus on appliance water use to make that case. Hence my understanding that process water has to do with equipment and appliances. I will look further at some of these definitions, thanks.