Using BAS for M&V
M&V codes and standards
For new construction projects, a number of codes and standards are emerging to drive the process. One of the most common guides driving an M&V process is LEED, which includes general requirements for trend analysis to verify performance as a part of the Energy and Atmosphere credit. Under EA Credit 5 for new construction projects, LEED offers a credit for developing and implementing a full-fledged M&V plan.
In addition to LEED, building codes in a number of jurisdictions are beginning to adopt Cx requirements that include M&V elements. The Seattle and Washington State Energy Codes are examples, in addition to Title 24 in California. In fact, the latest edition of Title 24, which will be effective in mid-2014, will drive new construction Cx processes toward requirements that are very similar to the requirements for LEED fundamental and enhanced Cx.
In contrast, M&V in existing building Cx processes tends to be driven either by the owner or the requirements of a utility incentive program that is funding the project, as mentioned previously. For example, the University of California/California State University/Investor Owned Utility (UC/CSU/IOU) MBCx program generally requires two different forms of M&V:
- For the initial RCx phase, energy savings incentives are based on the difference between a whole building meter consumption baseline, which is established prior to implementation, and the baseline that exists at the whole building meter after implementation.
- For energy conservation measures implemented subsequent to the initial RCx effort, the savings are incented based on engineering calculations. However, the validity of the calculation is frequently verified using M&V strategies, either at the whole building level or at the system level.
Regardless of the Cx process, most M&V standards and code requirements trace their roots to the International Performance Measurement and Verification Protocol (IPMVP). This standard sets rigorous requirements regarding the protocols, methodology, and tools used to quantify resource savings. In general, and with regard to M&V methodologies, IPMVP suggests four options for determining savings, including retrofit isolation by measuring certain key parameters, retrofit isolation by measuring all parameters, whole facility energy measurement, and calibrated simulation.
During a RCx project, depending on owner project requirements (OPR), input from the operation and maintenance (O&M) team during interviews, and the RCx agent site visits and reviews, a set of goals will be introduced as part of an M&V plan draft. This draft will be reviewed by the owner’s team and finalized. This document will define the extent of M&V. In general, a RCx M&V plan includes the following:
- The timing to put the RCx contract in place
- Potential preparations prior to each site visit
- Site visit timing and requirements
- Identification of systems (should be included in the RCx project and are part of the M&V plan)
- Assessment of BAS and control points for each system to identify control points that should be trended
- Identification of tools (direct and/or indirect monitoring) for launching the trending process
- Data analysis schedule
- Development of energy and water saving measures and O&M opportunities
- Quantification of energy and water saving measures
- Writing a draft report, owner’s review, final report issuance, and presentation.