Measurement and verification (M&V) involves recording actual energy use over the course of occupancy, and comparing that data with the estimated energy use seen in the design. The M&V process ensures all systems are performing as specified and identifies any anomalies in equipment, operations procedures or user habits. In addition, an M&V plan can help reduce energy costs, assist with commissioning, and, over time, document and improve the efficiencies of energy conservation measures.
M&V gives you a plan and a system to compare your project’s actual performance against design predictions. While M&V can be applied to a variety of metrics including water use and indoor environmental quality, this credit focuses only on energy performance. To earn it, you’ll need to develop an M&V plan, install devices to support the plan, and also have steps in place for corrective action. The credit requirements don’t tell you exactly what systems to monitor—that depends on your mechanical system design and what equipment you have installed. In general, you are expected to monitor energy from all systems or components that will provide data points for end uses identified in the energy model and that will help in the recalibration of the model.
The cost of M&V varies a lot. Added costs come from designing and installing specific monitoring systems, including adding multiple meters and wiring. The cost is higher in larger and more complex buildings or those with multiple uses. The cost premium will be lower if your project already plans to include a Building Management System (BMS) or submeters to record usage data. If your building is small with a minimum set of uses, and needs only few meters to meet the credit, an M&V system might also be relatively affordable.
For large buildings that have complex mechanical and electrical systems and that do not have a BMS, adding the equipment and systems needed to implement an M&V plan is likely to be cost-prohibitive. Some projects also find that Option B (see the Checklists tab) is particularly costly due to the requirements of added meters and wiring.
Despite aiming high during design, LEED-certified buildings don’t always perform as well as expected. An M&V program will not only help building operators be aware of performance issues, it can locate the source of problems or poor assumptions, and provide a better overall understanding of the value of energy-saving strategies.
To make the investment worth it, the owner must be committed to developing and implementing the M&V plan, analyzing and understanding the building’s performance, and acting on the results. The cost premium of M&V installation and operation is typically offset by long-term energy savings, but this is highly dependent on the building type as well as the owner’s willingness to make needed changes and upgrades. The credit is generally more applicable for larger commercial buildings than residential buildings since its cost benefits may not affect the developers directly. Residential buildings may also see less benefit because the building operator has little control over energy use by residents.
The “M&V provider” takes responsibility for developing the M&V plan. This role can be filled by the commissioning agent, energy modeler, mechanical engineer, project engineer, or a facilities manager.
The industry standard for M&V, both in the U.S. and internationally, is the International Performance Measurement and Verification Protocol (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.), owned by the nonprofit Efficiency Valuation Organization. LEED has singled out Volume III of the IPMVP guidance as the basis of its requirements. Several organizations have published M&V guidelines based on IPMVP. Among them are ASHRAE, the U.S. Department of Energy’s Federal Energy Management Program (FEMP), and some utilities and states that fund energy-efficiency projects. Some organizations with M&V standards offer guidance in writing M&V plans, including sample language. (See Resources for more information.)
Although no specific metering is required for this credit, the following list outlines energy uses that are often included in the M&V plan (where applicable).
A measurement plan can include a sampling of units, and must include end uses. However, the metering does not have to be permanent. A short-term metering plan could be worked out with occupants in the units being sampled.
No. DDC control points are not intended to measure energy consumption.
It depends. This usage must be included in your models. If they are a significant energy user (say more than 5% of gas usage) then yes the energy use should be measured or derived. If the usage is small you might be able to make the case that you would not need to measure it.
Generally, if you have interactive energy conservation measures (ECMs) in new construction, you need to follow option D. Most new construction has interactive ECMs, and Option B is very rarely accepted by LEED reviewers for this reason.
No. This is a consistent source of confusion and is not an ASHRAE or LEED requirement. You should always model the process loads as accurately as possible to reflect the actual building equipment and operation. If the baseline is less than the 25% default, simply note why that is the case.
No. It can be a manual measurement, short-term trending device or permanent submeter. In certain situations an energy end use does not need to be "measured" at all but can be derived based on other data.
This part of the M&V Plan can't be very detailed since you do not yet know what needs to be done. What you will do depends upon the issues uncovered. In general the action plan simply identifies what you will do when deviations occur between the projected savings and the actual savings. Typically this involves identifying additional energy saving strategies in the facility and using the calibrated model, for example, to determine additional energy savings. The cost and savings of the additional energy saving measures should be summarized in the final M&V report. It's a good idea to indicate that the owner will be responsible for implementing these recommendations as budget and time allow.
Consider incorporating a Building Management System (BMS) into the building. A BMS will streamline implementation of this credit, while offering other benefits.
Consider the impact of an M&V system on space requirements. Keep in mind that a BMS will require additional space for monitors, wiring and sensors.
Consider the impact of an M&V program on mechanical system design requirements. Consider whether or not your mechanical system is capable of providing the necessary outputs for the BMS or monitoring system. The outputs are typically the energy usage recorded as kWh, Btus or therms for a given period of time. It may be an automated record kept by the BMS, or a metered reading on the equipment manually carried out at regular intervals. The specifics of the output metric and duration would be determined in the M&V plan and depend on the system installed.
The “M&V provider” develops M&V plan. This role can be filled by the commissioning agent, energy modeler, mechanical engineer, project engineer, or a facilities manager.
Contract with the M&V provider early in the process so that system components and recommendations can be implemented seamlessly into systems rather than becoming add-ons.
Discuss as a team whether M&V will contribute to the project’s goals for energy reduction and systems monitoring. Consider the project size, its complexity, and whether you plan to run a whole-building energy model. Also think about how the building is likely to be operated. If the system is not likely to be fully utilized, it may not be an appropriate investment.
Determine whether 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. Option B or Option D is most appropriate for the project design. (Option C, which was allowed in earlier versions of LEED, is not allowed, as it is considered less accurate, and doesn't allow for M&V of individual energy conservation measures.)
Data to support calculations (Option B) or calibration of simulations (Option D) is taken from a combination of meters and sensors included in the building automation systems, and through temporary installation of additional sensors and data loggers as needed.
Energy savings is determined by comparing actual metered or measured energy use to the projected energy use of a baseline building under similar operating conditions.
Talk to the facility operations staff about the financial benefits and operational requirements of the M&V plan. Any energy savings achieved through M&V will depend on their participation.
Introduce the M&V program into the design early in the process, because it can affect the design of the mechanical and electrical systems as well as the BMS. There is also inherent value in having the design teams think about how the building will be operated.
Metering individual hotel rooms may not be feasible due to inconsistent occupancy and limited ability to control energy usage. If your hotel project includes M&V, you must track occupancy data based on daily sales records. Metering all common spaces can benefit operations, though it won’t be sufficient to earn the LEED credit.
Multifamily residential buildings are required to submeter all apartments individually and to collect data from occupants. Usage information may be made available to the occupants and energy cost savings may be transferred in lease or sale contracts.
Utility companies may provide incentives or rebates for submetering and BMS programs. For example, New York City provides $2,000 per meter for advanced master meter installation in affordable housing and $1,500 per meter for market-rate housing. Check with your local utility to see if they provide any rebates.
The cost of M&V varies significantly from one project to another. Projects will need to get project-specific bids based on their individual design needs. The usefulness and the cost of M&V plans are influenced by the following:
An M&V program that is implemented throughout the life of the building will provide the highest return on investment. Design your M&V program for use throughout the life of the building to provide the highest return on investment.
Isolating and metering different ECMs, such as HVAC systems or lighting, can provide useful information on energy consumption and provide insight on energy reduction measures.
The cost implications for ECM isolation depend on how many meters are installed and the complexity of the systems being monitored. See the appendix in ASHRAE, Guideline 14 for estimating the cost of meters. If systems are easily isolated and don’t require many meters, this credit can be relatively cheap, with Option B being more cost-effective than Option D.
Sub-metering different use areas in mixed-use buildings, such as office and laboratory space, can offer insight into what energy reduction measures will be most appropriate for different use spaces.
Option D is the best choice for projects with highly efficient building envelopes and efficient mechanical and electrical systems.
Permanent submetering or a BMS is not necessary. Project teams can instead choose a combination of utility analysis, spot-metering and permanent metering. However, these other methods will not provide the detailed information that a BMS would and may not help projects determine energy problems or understand actual energy use. An M&V plan without a BMS is rare in large new construction projects, but smaller, single-occupancy buildings may find that packaged energy monitors or monthly utility bills can provide helpful feedback without the investment in a costly BMS.
Most M&V programs submeter individual systems such as lighting, heating, and cooling. Plug loads are not always submetered individually, it is easiest to individually submeter larger items and subtract the totaled submeter number from the total building usage to get the estimated plug load number.
An M&V program generally includes sensors—which measure the volume and rate of flow, watts of energy draw, temperature, length of time, and other variables—and a central processor—which stores the collected information and helps building managers interpret it. Building automation systems typically include the central processor needed for M&V, but not all of the sensors, or the additional programming to tally energy use and track patterns. Adding these pieces to a building automation system should be easy, though.
The cost implications of this credit vary from one project to the next. Costs will depend on the complexity of the meter and sub-metering system, the cost of energy modeling and calibration, the cost of commissioning, and the size and complexity of the building. The cost premium for M&V will be lower for projects that already include a BMS.
The cost to create a M&V plan for Option D is influenced by the following, according to IPMVP:
Determine the extent of the M&V program based on the owner’s goals, the project type and function, and IPMVP requirements. M&V goals can be included in the Owner’s Project Requirements and Basis of Design documents for EAp1 and EAc3.
The M&V provider reviews the project design to determine which systems and equipment will be metered, and also determines how many meters will be required
The M&V provider works with the MEP to verify that all systems are designed to allow metering and submetering. Meters must be capable of interfacing with the selected BMS or metering system.
The MEP designs and specifies the appropriate submetering devices, controls and M&V system. The M&V provider verifies that the M&V program and systems are capable of providing the information required for the credit.
Permanent installation of water meters will allow easier monitoring of water consumption and savings. Although this is not required for LEED, water metering for graywater and rainwater systems is generally included in M&V plans, and monitoring general water use is also worthwhile, to verify projected savings.
Adding a M&V program to the project after mechanical and electrical systems have been designed may be cost-prohibitive due to redesign costs.
The M&V provider determines all of the ECMs that need isolation and verifies that these systems do not interact with any other ECM.
The M&V provider works with the owner and MEP to determine the best solution for metering or submetering ECMs.
The M&V provider works with the owner to determine the best system for monitoring actual energy use.
Run a preliminary energy model. If an energy model is being developed for EAc1: Optimize Energy Performance, the model can be used as the energy use baseline for the M&V plan. Otherwise a new model may be run to determine the baseline energy use. The actual energy use will be compared to this baseline.
The BMS should be set up to collect data that will allow fair comparison between actual and predicted energy use. For example, since weather patterns are factored into the energy model, the BMS should capture these, along with other parameters such as operating schedule, occupancy density, space use, and system settings.
To achieve this credit under Option D, the M&V plan must be able to identify specific building performance issues. A BMS or submetering will be able to build this capacity into the system.
The Whole Building Calibration Simulation requires information about the instruments that enable the project to monitor the categories listed in the IPMVP.
The question of which systems need to be monitored is building-specific and is not prescribed by the credit requirements.
Total energy consumption of the building must be tracked, along with any variables that may influence energy consumption. For example, in a hotel you would need to track occupancy.
Projects must verify the savings of the efficiency measures. If individual metering capacity is not built into the project, the project must demonstrate some other firm commitment to obtaining this data. This requirement can be accomplished by providing a copy of the contract for data collection by a third party of individual meters.
The M&V provider writes the M&V plan. If possible, involve the facility’s operational staff in writing the plan. The plan should lay out the measurement and response protocol. The M&V plan must define the following:
The industry standard for M&V plans, both in the U.S. and internationally, is the International Performance Measurement and Verification Protocol (IPMVP), owned by the nonprofit Efficiency Valuation Organization. LEED has singled out Volume III of the IPMVP guidance as the basis of its requirements, and several organizations have published M&V guidelines based on IPMVP. Among them are the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE); the U.S. Department of Energy’s Federal Energy Management Program (FEMP); and some utilities and states that fund energy-efficiency projects. Some organizations with M&V standards offer guidance in writing M&V plans, including sample language.
Coordinate with the mechanical and electrical engineers to verify that the control devices will be able to provide the information needed for credit compliance.
The owner’s goals and IPMVP guidelines should drive the M&V plan, which should specify which systems are to be sub-metered and which are being spot metered, and how. The plan also explains how the energy end use is being predicted and measured, and how the M&V information will be used, such as adjusting building operations to reduce energy use. The plan shall also include a section on corrective action that will take place if the baseline energy use and the post-construction energy use vary greatly.
The plan establishes who is responsible for managing the process during operations and for taking corrective action. The plan also establishes how long the monitoring will continue.
The M&V provider demonstrates through a narrative that the M&V plan will be able to verify actual energy use. For energy systems that are not addressed in the M&V plan you will need to provide a detailed reason for exclusion in the narrative.
The M&V plan should define the actions that will be taken by the facility manager to investigate the cause of any discrepancies found and correct any malfunctioning equipment. If goals are not met, or if unexpected performance occurs, the M&V systems will provide useful feedback in tracking the source of problems.
Variable loads such as dimming controls can be profiled with short-term measurements that determine a load value pegged against another variable point that can be measured or accurately estimated over time. ECMs have to be metered to obtain actual savings. Variable loads like dimming controls can be measured only by metering them first at full power and then at low power. Measure and plot the power use at various dimming points at consistent time intervals.
Determine the baseline energy use for the ECMs.
The projected baseline energy use can be determined using energy efficiency standards or guidelines.
Run a final energy model that reflects all of the as-designed energy-efficiency measures.
The projected baseline energy use is calculated by an energy model during the design phase. All ECMs are removed from the model and this energy data becomes the baseline to determine energy savings when compared to the actual energy use. According to Option D of IPMVP III, the model must be calibrated so it is ready to be used after one year of data collection.
It is easiest to calibrate the as-built energy simulation software if submetering devices correlate with the breakdown of the energy usage in the energy model.
Where applicable, the M&V plan should specify submetering sensor locations. Define the specific sensors with their location and sampling rates. In the plan, define the required energy model output and how measured data will be compared to the energy model. Also define how loads are arranged and grouped in electric panels; mixing power, lighting and HVAC equipment loads within individual panels is not recommended.
The M&V submetering devices or BMS are installed and commissioned to verify functional accuracy.
Installation of the M&V system should be fairly straightforward. Depending on the system and the experience of the subcontractors, however, specialized contractors may be needed.
Verify that the whole-building simulation model matches the as-built design.
The M&V plan is implemented for at least the first year of building operations.
Ensure that appropriate personnel are trained to optimize the system to its greatest potential.
Track and archive trending data with utility metering and energy submetering systems required by the M&V plan.
Provide a yearly summary report that identifies energy performance issues and corrective actions.
If there are discrepancies between projected energy use and actual use, identify the cause and follow the M&V plan for corrective action. Discrepancies may result from inaccuracies in the simulation model, actual building use that differs from anticipated occupancy, improperly functioning equipment, and switches and controls not being properly calibrated.
Meters and submeters should be recalibrated periodically according to manufacturers’ recommendations.
Encourage the operations team to focus on running the building at optimal efficiency.
Record any post-construction upgrades or changes to operations and maintenance in order to best understand post-construction energy use.
A 5%–10% discrepancy between the baseline energy use and the post-construction energy use may account for operational changes in a good energy model. However, a 25% discrepancy would not be out of the ordinary.
The payback period for M&V programs depends on the initial cost of additional meters and whether the program identifies inefficiencies that wouldn’t have been found otherwise. Some fixes may be substantial and will pay for the metering system. After the BMS or metering system has been installed, the true return depends on the commitment of the owner and operational staff. Because M&V monitors actual building operation over time, M&V procedures can lead to valuable operational savings by uncovering building system design, installation, and control issues not caught by commissioning.
M&V systems require continuous energy use and staff attention. One of the larger costs associated with this credit is the time needed by staff to read, interpret, and act on feedback provided by the M&V system. Although more expensive to install, a complex building or a building with multi-tenant spaces can benefit financially from an integrated computerized BMS that assists in day-to-day management.
The facilities manager or M&V provider compares the baseline energy use of the ECMs to the post-construction energy use.
The ECM usage can be tracked with a simple spreadsheet and does not require complicated calculations or modeling.
Set up the BMS to provide monthly reports as required by the M&V plan, if applicable.
Perform a calibrated building energy simulation model that reflects actual occupancy and weather, after the first year’s energy usage data becomes available. The energy modeler performs the calibrated simulation with the assistance of the M&V provider.
The calibrated energy simulation gives the owner and facility operator a true picture of savings from the ECMs instead of the predicted savings from the energy model developed during design. A simulation model developed during design makes a lot of assumptions on occupancy patterns, set points and weather. A calibrated energy model replaces those assumptions with real data while accommodating unforeseen program changes. If the actual results are greater than 10% from the predicted ones, compare the differences between the assumptions and the actual settings. Calibration is a great learning opportunity for the modeler to verify those assumptions with actual data. After the first year, you do not need to recalibrate the model, instead using energy usage from utility bills to compare against energy usage from previous years. The calibrated model is compared to the actual energy consumption rates and changes need to be made to the model until acceptable calibration is achieved. After all calibration adjustments have been made to the as-built energy model the same changes need to be made to the baseline energy model.
Energy savings is verified by either comparing the calibrated as-built model to the calibrated baseline model, or by comparing the calibrated baseline energy use to the actual metered energy use.
Twelve months of data from the metered categories is used to calibrate the computer simulation model. The M&V plan shall demonstrate the ability to identify specific problem areas if discrepancies exist between the modeled and metered data. When calibrating the as-built energy model, weather patterns must be reflected. You may be able to obtain this through the BMS. Calibration changes will also include occupancy and operational adjustments to reflect actual usage.
Calibration of the energy model will add a small cost on top of the cost of the baseline as-built energy model.
Excerpted from LEED 2009 for Schools New Construction and Major Renovations
To provide for the ongoing accountability of building energy consumption over time.
Develop and implement a measurement and verification (M&V) plan consistent with Option D: Calibrated Simulation (Savings Estimation Method 2), as specified in the International Performance Measurement & Verification Protocol (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.), Volume III: Concepts and Options for Determining Energy Savings in New Construction, April 2003.
The M&V period must cover at least 1 year of postconstruction occupancy.
Provide a process for corrective action if the results of the M&V plan indicate that energy savings are not being achieved.
Develop and implement a measurement and verification (M&V) plan consistent with Option B: Energy Conservation Measure Isolation, as specified in the International Performance Measurement & Verification Protocol (IPMVP) Volume III: Concepts and Options for Determining Energy Savings in New Construction, April, 2003.
Meet MPR 6 through compliance Opttion 1: Energy and Water Data Release Form. Projects must register an account in ENERGY STAR’s Portfolio Manager tool and share the project file with the USGBC master account.
Develop an M&V plan to evaluate building and/or energy system performance. Characterize the building and/or energy systems through energy simulation or engineering analysis. Install the necessary metering equipment to measure energy use. Track performance by comparing predicted performance to actual performance, broken down by component or system as appropriate. Evaluate energy efficiency by comparing actual performance to baselineperformance.
While the 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. describes specific actions for verifying savings associated with energy conservation measures (ECMs) and strategies, this LEED credit expands upon typical IPMVP M&V objectives. Measurement &verification activities should not necessarily be confined to energy systems where ECMs or energy conservation strategies have been implemented. The IPMVP provides guidance on M&V strategies and their appropriate applications for various situations. These strategies should be used in conjunction with monitoring and trend logging of significant energy systems to provide for the ongoing accountability of building energy performance.
For the corrective action process, consider installing diagnostics within the control system to alert the staff when equipment is not being optimally operated. Conditions that might warrant alarms to alert staff could include:
Besides control diagnostics, consider employing retro-commissioning services or dedicating staff to investigate increases in energy usage.
M&V blog that is a place where the community can raise and discuss issues that arise in the practice of valuing efficiency projects.
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. is the standard upon which the LEED M&V requirements are based. Use these documents should be used in designing the M&V system and plan.
This website provides a list of resources to help teams implement an M&V program.
These M&V guidelines are written for federal buildings but could be helpful for many projects.
ASHRAE provides technical guidelines for designing an M&V plan. This document can assist project teams in designing and implementing the M&V systems and plan.
The Energy Valuation Organization, in conjunction with the Association of Energy Engineers, offers an M&V professional certification program. The Association of Energy Engineers holds training seminars for those preparing to take the certification exam and anyone else interested in learning the fundamentals of M&V and working with 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..
Chapter 27 covers Measurement and Verification of Energy Savings and has some very useful information from the history of M&V, including various methods and equipment.
This article discusses the usefulness of M&V, including examples of problems that M&V systems have been able to identify.
NOTE: WATERGY is not currently available, but may be again in the future.
WATERGY is a spreadsheet model that uses water and energy relationship assumptions to analyze the potential of water savings and associated energy savings.
USGBC’s Building Performance Partnership (BPP) engages commercial and residential LEED building owners and managers in an effort to optimize the performance of buildings through data collection, analysis and action. This partnership among USGBC and the thousands of LEED project owners will result in the population of a comprehensive green building performance database, enable standardization of reporting metrics and analytics, and establish new performance benchmarks. USGBC’s BPP participants are eligible for annual performance reports, report cards and real-time data interfaces to aid in their building performance goals. Together, USGBC and BPP participants will transform the way the world views building operations.
The Measurement and Verification (M&V) plan template shown here is based on Option D: Calibrated Simulation.
The following links take you to the public, informational versions of the dynamic LEED Online forms for each Schools-2009 EA credit. You'll need to fill out the live versions of these forms on LEED Online for each credit you hope to earn.
Version 4 forms (newest):
Version 3 forms:
These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictsions for these forms; for more information, visit LEED Online and click "Sample Forms Download."
Documentation for this credit is part of the Construction Phase submittal.
This Measurement and Verification (M&V) plan sample follows Option D: Calibrated Simulation.
I'm working on a building that is part of a larger facility. The domestic hot water is produced at a central plant. Does anyone have experience with this and if so, did you monitor the energy use for the domestic water heating? If not, does anyone know if this is required? In looking into this, the focus appears to be on the HVAC systems.
In order to calibrate the model by each energy end use you must measure or be able to derive them all. Typically this means you collect some data (could be a spot measurement, short-term trend or permanent meter) on most systems. Since the energy use for DHWDomestic hot water (DHW) is water used for food preparation, cleaning and sanitation and personal hygiene, but not heating. is not within the building it would seem to make sense to meter the incoming HW at least for a period of time.
The focus of M&V is on determining energy savings, not just related to HVAC systems.
If it were only that simple, but with two connection points and hot water return, it actually means metering multiple water lines. But I do agree with your comment, it is about energy use, and there is energy there.
This brings up an important issue. M&V needs to be planned during design. If you will need to sub-meter it is always better to plan for it in the design/layout of the system. This usually enables the sub-metering to be done as cheaply as possible. Not sure if it would have helped in your specific situation Jonathan but reading your post triggered that thought.
If we pursue this option, are we only eligable for one point for this credit? That's what is coming up on my template, even though it says that i'm pursuing two credits.
Yep that option is worth one point.
Not sure why it says you are pursuing two credits?
We have a debate going in our office about whether Sub-Meters are required (or Not) for the Option D - Whole Systems Simulation method. In LEED NC V2.1, sub-meters were explicitly required, but over the years things have changed....2.2 and 2009 have softened their requirements for sub-metering and they refer to the 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. Volume III for Guidance.
We've been doing sub-meters / sub-measurement on new projects because we think it is worth the cost; therefore we haven't even tried M&V without sub-subsytem feedback. We now have a commissioning agent that is seriously questioning our decision to sub-meter / sub-measure the project systems, but we think the project complexity warrants some feedback at the systems level and depending on the interpretation - that the credit would require it.
What is the general opinion? Are Sub-Meters totally up to the discretion of the team, on any project (excluding C&S applications)?
Is a high quality, calibrated energy model compared against the whole building meters one year after the completion of commssioning (along with a M&V plan and recommendations for improvements) all that is needed to earn Option 1 / D - no matter what?
And last but not least - Is the issue here really a language barrier around the definition of "Metering" and "Measuring" sub-system performance? I.E. Is 'Measuring' sub-systems potentially required?
Looking forward to the Opinions on this one...
Submeters are not required (actually they never were required despite the language in v2.1 since the 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. never required them, that was a mistake and the EA TAGLEED Technical Advisory Group (TAG): Subcommittees that consist of industry experts who assist in developing credit interpretations and technical improvements to the LEED system. regretted it for quite some time).
It is possible to develop a M&V Plan which gathers the necessary data through spot measurements and short-term trending. The real issue is related to the cost of optaining the data. For small facilities without a central control system it makes sense to not install sub-meters, especially on the electric end. For large ones a sub-metering system will likely be far more cost-effective than gathering the data via more manual methods. Projects should do either (or both) in alignment with common sense. Get the data the cheapest way possible.
Yes all you need for EAc5 is what you describe. The Plan is the key. Regarding this specific issue - will the Plan gather the data needed to calibrate the model? There are multiple ways to do so and all are legitimate.
Yes measuring, not metering, by energy end use is required to sucessfully calibrate a model. Not necessarily every end use but the ones not measured need to be derived from measurements. For example, if the lighiting and HVAC are measured one could derive the plug loads (assuming that covers all the electric loads).
Marcus - thanks for the excellent response.
We should put in big bold letters -"Measuring, not Metering".
Marcus and Christopher - Thanks for the response! This is very helpful.
We reached a similar conclusion - that permanent sub-metering is not required per 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.. However, in my experience, some 'Real-Time' feedback is needed for non-constant loads like daylight dimming, VFDA variable frequency drive (VFD) is a device for for controlling the speed of a motor by controlling the frequency of the electrical power supplied to it. VFDs may be used to improve the efficiency of mechanical systems as well as comfort, because they use only as much power as needed, and can be adjusted continuously.'s, and other loads to accurately calibrate the model (as your comments point to Marcus).
From your experience, would it be appropriate to say the trending data through an energy managment system would (likely) meet the sub-system feedback needs for most M&V applications / model calibration?
One last question(s) - Is their an industry recognized definition that provides clarity around the term 'Metering' (I.E. is there a level of accuracy or an accepted method for the design of instruments that make them qualify as 'Meters'?). AND would digital measurement from a Energy Management System, that may not be as accurate as other kinds of 'Metering' qualify as 'Metering' for the LEED Credit (I'm sure the answer could easily be 'it depends').
Thanks in Advance for you reponse!
I agree that some of the highly variable loads need more thorough measurement or metering.
Projects most certainly can trend data in an EMS. It is probably by far the most common way to do so in larger facilities which have one. This type of measuring definately does qualify under 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. and LEED.
Not sure if there is a recognized level of accuracy for meters in general. What is acceptable does depend on the level of accuracy required by the project since typically higher accuracy cost more money. The IPMVP does not specify meter accuracy ranges, as far as I know, to allow projects teams to determine what works for the individual project. ASHRAE 14 addresses calibration procedures since the accuracy range is only valid in a calibrated meter.
This can be a key component of overall measurement uncertainty which is something that should be addressed by the M&V Plan. Acceptable uncertainty is influenced by budget and complexity. The goal is to reduce the level of uncertainty as much as possible. The overall acceptable level of uncertainty will influence the acceptable range of individual metering accuracy. The overall effect of the system being metered will also influence the desired level of accuracy for that meter(s).
So if your overall acceptable level of uncertainty is +/-5% then your individual meters can't be +/-5% since they would then take up all of the allowable uncertainty.
With all that said we would typically like to see electrical meters in the +/-0.25% to +/- 1.0% range and gas meters in the +/-2% range.
Thanks Marcus! This is great information.
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