Systems commissioning has proven its value to many owners in facility construction and renovation projects. When properly executed systems commissioning leads to fewer contractor call-backs and problematic functional issues. While some level of commissioning makes sense for every project, the value of commissioning tends to increase in proportion to the size and complexity of the project.
The proportionality of size and complexity to value can be readily illustrated by considering building space heating systems. If a project calls for a single zone, forced air heating system, there is certainly value to verifying that the correct system has been selected; that the air flows and temperatures are adequate; and that, upon installation, fans, heating devices, and thermostats all function as intended. But the likelihood that a competent designer and/or installer will make a major error with such a simple system is small; and the cost and potential disruption, should anything go amiss, may not be excessive. Therefore, a cost conscious Owner who trusts his or her designer/installer may opt for a simple equipment start-up rather than an exhaustive, and more costly, commissioning effort.
A large building, on the other hand, may require a much more costly and complex system, consisting of boilers, heat exchangers, pumps, heating coils, fans, humidifiers, dampers, heat recovery equipment, and control valves are all working together under the control of a digital control/automation system. System functionality will often depend upon coordination with structural elements of the building, such as glazing, insulation, and vapor barriers.
In addition to deciding upon an appropriate scope for the commissioning effort, there are other issues to consider that will help drive value from a commissioning effort.
Mutual understanding
It is important that all stake-holders in the commissioning effort understand how the commissioning process will be implemented and the full extent of the commissioning objectives. This will help drive answers to questions such as the following:
- Should the commissioning agent be a member of the design team or an independent third party?
Many design engineering firms possess the skills to commission their own work, and they like to do so because it reduces or eliminates confusion with regard to responsibility should problems arise later – if the same company designs and commissions the systems, there is only one call to make when something seems wrong. Some Owners, however, opt for a third party commissioning agent because they don't want "the fox guarding the hen house." (Some would say that if an Owner thinks his engineer is a "fox," he should find a different engineer – but that's a topic for another time.) - Participation by the installing contractors
Do the project specifications require the contractors to furnish labor and test equipment and to perform pre-functional testing in support of the commissioning effort? If not, who will do this? - Grants and certifications
Are grants or certifications (such as LEEDTM) being sought? If so, there may be a requirement for third party commissioning. Also, it is important to understand any reporting or measurement and verification requirements of the granting or certifying agency.
- The final report
How will the final commissioning report be presented – in binders or in a digital format? What information will it contain (for instance initial set points, seasonal adjustment data, a defects & corrections report)? Will the report incorporate equipment submittals, test and balance reports, and electrical testing data? Will the report be searchable and user friendly so as to be an effective tool for building O&M personnel?
Each of these considerations should be discussed and mutually understood by the commissioning agent, the design team, the contractors, and the Owner. And all must understand that the commissioning agent's sole responsibility is to validate for the Owner that the design and installation will meet his clearly delineated expectations.
During the commissioning process, the commissioning agent's communication with the owner, contractors, and design team must be consistent and actionable, based on clear lines of responsibility established among all parties. It must be understood that the commissioning agent is not on the project to direct the contractors -- his purpose is to verify, record, and communicate observations continuously with the owner.
When commissioning is conscientiously and systematically planned and performed with buy-in from all stakeholders in the design and construction process, the value to the Owner, in terms of building systems efficiency, functionality, and maintainability can be significant. A haphazard or non-collaborative approach will most often be a waste of time and money and result in inferior building performance.
About the Author: John Stephens, P.E., LEED AP, CxA