Hi Jeff

The consumption should be based off of one year of energy data, and the total annual breakdown of consumption should be fairly close to what is represented in EAp2 as the total annual consumption for site energy use.

Ideally, this breakdown would be completed using actual consumption data, using existing 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). and spot submetering where available, and performing engineering calculations to determine breakdown.

Using a known database, such as CBECSThe Commercial Buildings Energy Consumption Survey (CBECS) is a national sample survey that collects information on the stock of U.S. commercial buildings, their energy-related building characteristics, and their energy consumption and expenditures. Commercial buildings include all buildings in which at least half of the floorspace is used for a purpose that is not residential, industrial, or agricultural, so they include building types that might not traditionally be considered "commercial," such as schools, correctional institutions, and buildings used for religious worship. CBECS data is used in LEED energy credits., could be a good place to begin the process of developing the breakdown but in our experience, an acceptable breakdown needs to be supported by more detailed analysis of actual building use such as spot metering.

Thanks

Hannah

Hi Alicia

It doesn't appear that this meter would qualify. You would have to meter at the end-use or by the major system type.

Thanks

Hannah

Hi Tapio

This is a funny credit, where it requires you to measure systems and / or end-uses, which is a little confusing.

First off, you definitely don't need to install metering at the tenant-level, as this is not the intent of the credit. Additionally, the credit does not necessarily require teams to measure all energy uses downstream of an associated system / end-use level, but rather typically requires the main upstream system / end-use to be measured - in this case, the central AHUs.

That said, I'd wait to install metering until you've performed the energy breakdown that is associated with EA Prerequisite 1. If you find that the AHUs are one of the top users, then installing meters at the central air-handlers would help to earn this credit. But make sure to cross check the other credit criteria and metering requirements prior to submitting.

Let me know if you have any other questions,

Hannah

Tzvi

This sounds like it might work, as long as the aggregate of the sub-metered data covers 40% of the total annual energy consumption and 80% of the largest energy use category, based on the energy use breakdown. But you also need to take into account base-building energy consumption in your break-down.

Let me know if you have any other questions on this - the energy end-use break-down seems to be a driving point to achieving this credit.

Thanks,
Hannah

Emily

Is this permanent metering or spot metering? And why did you need to do this to comply with EAp2 / EAc1 (I'm just curious on the second question)?

Hannah

This is permanent metering and we did so because I'm on a campus where we have district heating and cooling and we needed to measure building-level steam, hot water, and chilled water usage as applicable at the building level. In some cases that meant metering at the system level.

Before submission.

Hi Paola

This is a great question. While I don't know much about the energy production system at your site, I'm assuming that there is some sort of central plant serving all three buildings. Is this correct?

If so, then you would have to have some sort of metering in place to quantify the percent of energy output of each system is going to each of the three buildings - this would be required to meet the energy benchmarking prerequisite, EAp2.

If this is the case, then you may already be meeting the credit criteria and intent, depending on the types of systems located within the central plant and how much of the overall building consumption these meters are covering.

In this scenario, I would say the safest bet is to submit a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide for this approach to GBCI prior to submitting your project and see if they view this as an acceptable approach.

Good luck and let me know if you have any other questions!

Hannah

Mitch

I feel that your approach sounds acceptable, and I even gave similar guidance to someone above. I think that language about the end user is to disuade people from submitting just because they meter individual tenant spaces (that would be the end-user bit).

But you'll need to verify that lighting and plug loads meet the minimum percent of total energy use. And depending on the building type, those systems are often low consumers.

CIRs are always a safe bet, even with their price tagLEED Technical Advisory Group (TAG): Subcommittees that consist of industry experts who assist in developing credit interpretations and technical improvements to the LEED system..

Hannah

Hi Matthew -

A BAS could be part of compliance with this credit. However, as I'm sure you know, in order for a BAS to track energy consumption by end use, it will have to be connected to building meters and submeters. It is the extent and coverage of these submeters that is the main focus of this credit. However, a BAS can certainly help with the requirement that meters be read "continuously, automatically, and electronically" (p. 199 of the LEED Reference Guide for Green Building Operations and Maintenance). Other electronic monitoring systems can serve this function as well.

If the BAS tracks run time of Air Handlers, is it possible to derive their energy use by comparing run time to the unit's rated energy consumption? This would be much cheaper than 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)..

I'm not sure that would fulfill the energy metering requirement Nell. I'm concerned that if you multiply the rated energy consumption by the run time you may get inaccurate results. For example, the compressor in the AC unit may not run all the time, or the fan may ramp up and down with a speed drive or pressure fluctuations on the system. This method would only work if the air handlers ran at factory-tested conditions every time they were turned on.

Is it possible to get a determination from the USGBC if they will accept BAS "virtual meters," such as:
- Spot-measured, constant-load motors with integrated average runtime recorded every 15 minutes; or
- kW signals from VFDs, chillers, etc. with integrated average values recorded every 15 minutes?
And the list goes on. I believe there is a good argument for meeting the intent of this credit using these techniques as long as the "meters" are fairly accurate, but more importantly that they are repeatable for reliable (comparative) management purposes.
Anyone in a position to gain such a determination?

"Anyone in a position to gain such a determination?"

You are, if you have a registered LEED project. Submit a credit interpretation request.