CS 2009 EAc5.2: Measurement and Verification—Tenant Submetering

Markus, my understanding that you do not have to provide the meters for tenant loads such as lighting. You only need to make sure that the BMS can handle inputs from future meters, and explain how the tenants will be able to access that information. I believe the tenant will need to have lighting separately metered for CI EAc3.

Markus,

LEED USER GUIDE is defining it quite clearly on page 322. "(...) The electricity used for lighting and plug loads and to run HVAC equipment may be measured on a single meter and reported together,"

Hope it will help :O)

The language regarding corrective action is indeed puzzling and I believe that it was included in error, although I have no direct way to verify this. I concur that in this context there is no way to monitor performance and implement corrective action. Credit 5.2 is simply about providing metering capability and advising tenants of the opportunity. At no point are "savings" or performance projected.

As described in various responses below, the general answer is that the CS building metering network must have the capability of accomodating the implementation of ID&C EAc3. This does not mean installing the meters themselves, but rather installing a data system capable of receiving, transmitting, and collating meter data from the tenant spaces. For some tenants this could be as simple as a single electrical meter. For others it could mean multiple meters for individual end-uses. It depends on whether the tenant is Case 1 or Case 2 under EAc3. In this regard, see my response to Mike Lui below for elaboration. More to your specific question, the CS system generally must be capable of managing decent volumes of data (e.g. hourly), since this is what will be required for most tenant spaces to meet the requirements of EAc3. To be blunt, I have difficulty imagining a tenant space where a simple "accumulating" meter and monthly reporting would be sufficient to meet the intent of EAc3. The physical format of the data network is up to your discretion - it could be any number of configurations including hard-wired, web/IP-based, etc. Having said all of this, consider what is appropriate and do what is sensible for your project. Far too many metering systems that I encounter are seriously over-designed and/or over-capable.

As I describe in the 2009 CI EAc3 M&V thread on this forum (see response to Julian Bott's inquiry), the CI EAc3 language has a number of problems. To reiterate:

Rather than reusing/rehashing the NC 2.0/2.1 language Case 2 should have adapted the 2009 BD&C EAc5 language (also used for NC 2.2). It cites IPMVPThe International Performance Measurement and Verification Protocol (IPMVP) provides best-practice protocol for measurement and verification of new construction. This standard is referenced in LEED's measurement and verification credits. Vol. III with specific guidance for the available options (Option C makes little sense for CI) and dispenses with the arguably flawed "old" list of prescriptive requirements. Instead, Vol. III inherently provides the necessary flexibility and discretion to deal with projects, including CI, on an individual basis.

The USGBC is aware of these problems and this posting will prompt me to follow up to see if any resolution has been reached regarding a correction. In terms of immediate advice, I suggest following the 2009 BD&C EAc5 language (using IPMVP Vol. III) and adapting it accordingly for CI. I can also confirm that the CI RG requirement for IPMVP compliance for Case 1 is also an error.

Regarding your second question:

Case 1 of CI EAc3 requires metering only at the tenant level, not submeteringSubmetering is used to determine the proportion of energy use within a building attributable to specific end uses or subsystems (e.g., the heating subsystem of an HVAC system). of end-uses/systems as required by Case 2 (notwithstanding the flaws in the Case 2 language as described above). In most cases this will mean total electrical usage for the tenant space as well as total natural gas, steam, or hot water as the case may be.

For LEED-CS 2009 EAc5.2, tenant submeteringSubmetering is used to determine the proportion of energy use within a building attributable to specific end uses or subsystems (e.g., the heating subsystem of an HVAC system)., should electrical usage monitor include HVAC electrical usgage? I mean most office building charge the heating & cooling electrical usage in their estate managing fees.

To some extent it depends on whether the future CI will fall into Case 1 or 2. If it's Case 1, then a single electrical meter for the tenant will suffice, with all electrical loads specific to the tenant being recorded by that meter. If it's Case 2, then individual electrical end-uses need to be disagreggated and metered. If the HVAC for the Case 2 tenant is provided by a central system, then it's a base building, not CI issue. However, if the CI has tenant-specific HVAC terminals that draw electricity (e.g. heat pumps), then those have to be specifically metered. Having said all of this, CS EAc5.2 only requires that the base building install the "backbone" of the metering system, not the tenant metering and/or submeteringSubmetering is used to determine the proportion of energy use within a building attributable to specific end uses or subsystems (e.g., the heating subsystem of an HVAC system). itself. In reality, differentiating between Case 1 and Case 2 future CIs is not going to make much difference to the design of the central metering backbone.