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Commissioning and Measurement & Verification

I had the honor of serving as moderator for a panel of experts at the Energy 2000 conference in Pittsburgh in August. The forum topic was “Commissioning and Measurement & Verification.” This was a fascinating discussion dealing with, among other things, the following questions:

  • How is commissioning different from Measurement & Verification (M&V)?

  • When would you use one versus the other?

  • Are they mutually exclusive?

It seems that these two processes have developed along separate but parallel paths over the past 5-10 years. Commissioning is the primary focus of this monthly column, but what is M&V?

M&V is a process by which energy goals for specific projects are measured and verified as having been achieved. It has become “business as usual” and often contractually required for many utility-sponsored conservation programs and for energy performance contracts.

When a utility puts up money towards implementing energy conservation measures for their customers, they want confirmation that the new or renovated systems consume no more energy than expected. This often involves “baselining” the original system performance by measuring energy consumption through a representative period of time (typically no less than a year) or by creating a computer model of the existing conditions. Following installation and startup of the energy conservation measures, actual energy consumption is measured via permanent and/or temporary instruments such as electric, water, and gas meters, temperature sensors, etc. This provides much needed feedback to the utility that their funds were appropriately spent and that their conservation programs are working.

Energy performance contractors are typically compensated based on the energy consumption (or reduction thereof) of the projects they design and install. In order to know how much the contractors should be paid, it is necessary to measure the energy consumption and apply that data to a contractual formula for payment. This may need to be repeated on a regular basis throughout a 10-20 year life of a contract to verify that the systems continue to operate as efficiently as they did following startup.

So, how does this relate to commissioning? It seems that the two processes should go hand-in-hand for the best project results. For M&V to be verification that energy goals are met, it would be a good idea to make sure the systems are commissioned as a part of their design and construction process. Commissioning aids the M&V process by not only confirming that systems physically perform properly at the end of construction but that those systems will continue to operate efficiently throughout their lives. This is accomplished by providing meaningful documentation and training to the people responsible for operating and maintaining them.

Similarly, commissioning can clearly benefit from formal M&V techniques as part of the verification testing portion of a construction project. Recommissioning (i.e., periodic “checkups” following commissioning of new systems) can also utilize M&V as part of the process of making sure that the systems are still operating at or near their peak performance. Finally, M&V makes a lot of sense for Retrocommissioning (commissioning existing systems/buildings which were not commissioned originally) where it can be used to demonstrate the effectiveness of the retrocommissioning process by measuring before and after energy consumption and other parameters.

In summary, M&V is not commissioning and commissioning is not M&V. It is important to remember that you can not make systems work by measuring them. Alternately, you can not make systems work by testing them. The commissioning process is more than both of these, because it starts during design and continues through construction to help ensure that the system performance and energy consumption goals are actually achieved when tested and measured. Testing and measurement is simply the culmination of the commissioning process.

M&V and commissioning are like any good team members. They are important and effective as individual processes, but, when combined, they enhance each other to be greater than the sum of their parts.

 

COMMISSIONING: GETTING IT RIGHT

Engineered Systems, October, 2000

Rebecca Ellis, PE, LEED AP, CCP, CxA
President
Questions & Solutions Engineering
1079 Falls Curve
Chaska, MN  55318
rteesmag@QSEng.com