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Commissioning Keeps on Giving

Commissioning is like a gift that keeps on giving, long after the initial shine has worn off. I am writing this a few days before Christmas and thinking about my children and how long they’ll play with the various games and toys awaiting them under the tree. There are some things not meant to hold anyone’s attention even until New Year’s and others that I’m hoping (probably in vain) will be enjoyed at least until the time this column is published in February. Of course, there are those “big” gifts that – based on how much they cost or how much effort went into making them – I am hoping will be cherished for much longer than that.

We’ve learned that one of the secrets to the longevity of many kids’ things is to put the toys or games out-of-sight once they have become “boring.” A few months – or even years later – they may reappear and seem new and exciting again. A client reminded me this week that the value of commissioning re-asserts itself periodically months, if not years, after initial construction, startup, and testing is completed.

This person is the in-house commissioning engineer for a large institutional organization. They completed functional performance testing of the HVAC systems serving a new research building last summer and are now dealing with a few performance issues popping up as the facility moves into full occupancy as well as its first winter. Instead of thinking that commissioning has failed because there are still “issues” with the systems, he articulated the appreciation he had for the commissioning process and resultant documentation.

This enlightened position comes from the fact that the troubleshooting and root cause analysis associated with resolving the current problems was greatly simplified by the initial commissioning checkout and testing. Because so many of the “hidden” features of the HVAC systems were systematically confirmed to be functioning properly at the end of construction, they were eliminated from the list of potential causes of the current problems. That left the owner with a much shorter list of what might possibly be wrong now – most of it associated with individual equipment and/or hardware failure covered under manufacturers’ warranties.

This has made dealing with post-construction performance problems significantly easier than what often happens in un-commissioned buildings. A typical scenario involves an HVAC system problem and 5-7 contractors/subcontractors, at least one design engineer, and the owner pointing fingers at each other and making no progress towards correcting the problem. Some of the lack of resolution is due to claims that controls, balancing, cleaning and flushing, design, or other non-visible aspects of the system were not done correctly. Owners who don’t formally commission their systems can be stymied by the claims and counterclaims of the various parties.

In this typical scenario, sorting through all of the claims requires the equivalent of a well-planned and executed commissioning process to positively identify what is working correctly and what is not and how various components and/or sub-systems are interacting. At this late stage of a project - or post-project - no one thinks they have the time, budget, energy, or motivation to undertake such a focused problem-solving approach led by an objective third party or knowledgeable owner’s representative. As a result, everyone is sucked into a long running series of meetings, memos, and bad feelings with no forward progress towards resolving the owner’s problem…and, somehow, this is supposed to be a better use of resources and goodwill?

Back to the good news for owners who have been through formal commissioning in the first place: there are a lot fewer unknowns behind which project team members can hide. If someone claims that the controls weren’t programmed correctly, there will be documentation that indicates that the controls were functioning as specified at the end of construction. If there is a question about whether the controls may have been corrupted or otherwise changed since the initial commissioning, re-running the functional performance tests or portions thereof is a relatively straightforward exercise. If DDC system-based trend logs were set up for the initial commissioning, they can be reactivated to quickly spot anomalies in component performance and/or control signals.

In short, what my client found when troubleshooting the problems in his 4 month-old building were almost all warranty items acknowledged by the responsible subcontractor who could call on the manufacturer to honor the terms of the respective warranties. Other issues involved control loop tuning under new seasonal conditions, something the control contractor understood was his responsibility. The problem solving process was simplified by the fact that many of the more complex system variables had already been eliminated as potential issues through the initial system commissioning process. This was a benefit to all members of the project team as well as to the building users who didn’t need to wait months or years for their environmental control problems to be resolved.

 

COMMISSIONING: GETTING IT RIGHT

Engineered Systems, February, 2006

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