I am glad to have a forum like LEEDuser to ask this question, since this has mystified me for many years. The M&V activities described by the credit language seem to me to do more benefit to the engineer than to the building owner. In essence, this credit is written to validate and calibrate the energy model, though it doesn't seem to have a direct focus on maximizing building and system efficiency. In my opinion, the real benefits of a sub-metering system are to:
1) Identify equipment that is malfunctioning: running for too long, not functioning at all, drawing energy at higher demands than usual.
2) Make effective use of maintenance staff by addressing small problems before they become big problems.
3) Decrease the likelihood of equipment failure as a result of neglect and the associated costs of new equipment and interruption of the activities of the building.
Am I missing something about the value of this LEED credit that is somehow larger than long-term energy monitoring?
Additionally, in the past I have written M&V plans geared towards long-term energy monitoring, and not validation of the energy model. These have generally been accepted, as we tend emphasize the human capacity in place to make use of the data and deal with exceptions. We have made general nods towards IPMVP Option D, but don't closely align to it. We use the first year of data as the baseline for comparison, as the systems are new and recently commissioned. Subsequent years/months are compared to those in the baseline to identify problems and exceptions.
However, in this new era of strict adherence to LEED language, I worry that this approach may no longer fly. Also, projects we have worked on focus on electricity consumption, and not gas or water. Does anyone have any guidance on how these are being reviewed and what exactly is considered acceptable these days?
Any insights would be appreciated.
Andrew
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
June 20, 2013 - 11:32 am
Many people have been highly confused about the fundamental purpose of this credit. In certain respects the credit intent is not in full alignment with the intent of the referenced standard. In LEED v4 the IPMVP portion of the credit was removed and the new credit will be more in alignment with your understanding.
The one thing I did not see in your post is the fundamental purpose of the IPMVP upon which credit compliance is based. The IPMVP was created to create a uniform set of methodologies to verify predicted energy savings. Some owners benefit from this pursuit, some do not.
The benefits of submetering are related to this credit but permanently installed submetering systems are not a requirement to comply with IPMVP. So if you submeter then yes there are operational benefits as you describe.
M&V Plans have been accepted that focus on the credit intent rather than IPMVP Option D compliance. It is not possible to say whether your approach would be accepted or not without thoroughly reviewing the details. In general is you are submetering the major energy end uses and have a monitoring and corrective action plan in place you can make the case that you comply with the credit intent even if you do not necessarily comply with the IPMVP Option D.
If you are following Option D then you will need to demonstrate in the Plan a detailed description of how you are going to gather the data one would need to calibrate the energy model, how you are going to go about calibrating the energy model and reconcile it with the actual utility bills to verify savings and what are going to do if the savings turn out to be less than predicted.