Hello,
We typically implement Option D of IPMVP and calibrate the model once one-year of actual energy data is obtained.
The proposed model than becomes the baseline and the actual becomes the proposed.
We can use this data to facilitate an energy audit if the actual does not match the proposed, especially if the actual use is much higher than expected.
In this instance sub-metering is not required. This method has been approved by GBCI on numerous occasions.
Recently GBCI provided technical advice that "sub-metering is required".
We are in the process of working with GBCI to better understand their concern.
Marcus, I am curious if you have anything to add or advise....although i am sure your are worn out by now when responding to "do we need sub-metering for EAc5 per IPMVP Option D?"
thanks!
Dave
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David Eldridge
Energy Efficiency NinjaGrumman/Butkus Associates
67 thumbs up
November 3, 2017 - 5:27 pm
What data did you list in the M&V plan to be used to calibrate the model without sub-meters?
Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
494 thumbs up
November 4, 2017 - 10:20 am
We have quite a bit of data listed within our M&V plan that needs to be reviewed post occupancy.... the building's Current Facility Requirements / Building Operating Plan / Sequence of Operations / actual FTE count and transients / equipment setpoints and run times as well as the actual weather for the first year of occupancy.
We use this data to confirm the assumptions we made when completing the energy model.
What we've found is that this is a great way to perform a quasi-energy audit and most all buildings' ES score jump a point or two since equipment runtime usually do not match occupancy, and equipment is left on too long. So while we do not have submeters that isolate fans, pumps, etc. there is still a good benifit to the building. During the post-occ review we also chat with the owner on EB/EBOM/O+M:EB/LDP/ARC (whatever it is called now..I can't keep up) so that the LEED building continues to perform optimally and perhaps pursue a performance certification.
I do agree with GBCI regarding the benifits of submetering, it's just that Option D does not require it therefore they cannot either.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5867 thumbs up
November 6, 2017 - 11:15 am
Yes no submetering is required by the IPMVP. There are a few ways to do calibrated simulation. The most accurate method is with submetering. You can also do what you suggest David and simply confirm all of the modeling inputs based on the actual building operation, equipment and systems. This tends to be far less accurate but the IPMVP allows you to state the level of accuracy you are intending so this is certainly acceptable.
Surprising that GBCI is "requiring" submetering in a comment. Reviewers are instructed not to do so, however, the direction the Plan is taking may have something to do with that. For example, if a Plan is submitted that appears to be relying on submetering to perform the verification (the vast majority of them go in this direction) then a reviewer can certainly ask about the extent of the submetering and how each energy end use will be addressed. This does not sound like the case with your Plan so asking for submetering information does not make sense.
Based on what you are saying it does not sound like you are relying on any submetering so as long as the Plan thoroughly details the information you are gathering to calibrate the model you should be OK.
One thing that does not make sense to me in what you say above is the proposed becoming baseline and actual becoming proposed. The whole point of implementing the IPMVP is to verify the energy savings. Doing what you suggest will not produce an estimate of savings, it will produce a difference between the adjusted prediction and the actual use. I don't think this complies with Method 2 which is required for LEED. Therefore your adjusted prediction modeling results cannot be a baseline for the purpose of estimating savings. Your baseline should be created to enable you to predict and verify savings. For most LEED projects that is an adjusted baseline model using Appendix G. Other baselines can be used but what you describe would not be an acceptable baseline IMO.
Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
494 thumbs up
November 6, 2017 - 2:44 pm
Hi Marcus, thank you for your response and expert clarification. Much appreciated.
My apologies for causing confusion on "proposed becoming baseline and actual becoming proposed". This was worded incorrectly. I was referring to IPMVP where it states within Option D:
"Use the energy use of the as-built building from the first stable or acceptable year of operation as the new baseyear energy use, and apply the regression methods of IPMVP Volume I to coorelate the baseyear energy to weather and other operational variables for subsequent periods. Essentially the as-built energy use and operating conditions for the first M&V year become the baseline for subsequent M&V periods, and subsequent savings are estimated relative to this new baseline."
I will post the final decision from GBCI on this thread once received.
thanks again!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5867 thumbs up
November 6, 2017 - 2:56 pm
Ok now it makes sense!
That after the first year, on-going M&V is not required by LEED except for Healthcare projects.