QSE Logo

LetsTalk2015@QSEng.com
612.308.4716

Commissioning: Construction Phase Commissioning Activities

At the end of last month's Getting it Right column we had a set of contract documents which clearly defined system configurations, operational sequences, and verification test procedures for systems being commissioned. At this point, you could, theoretically, sit back and wait for the systems to be installed and come back at the end of construction and perform the verification tests. However, how many buildings and systems are actually installed exactly as specified? The primary focus of the commissioning process during construction is often threefold:

  1. Keep track of any deviations from the design specifications.

  2. Prepare final verification test procedures based on the actual approved systems and sequences.

  3. Frequently remind the contractors of the commissioning process.

Changes and clarifications to the original design documents come in various forms. The commissioning agent needs to stay "in the loop" with respect to the systems being commissioned by being copied on meeting notes, approved shop drawings, change orders, etc. Some shop drawings, especially those which include sequences of operation, e.g., automatic temperature controls, fire alarm, security, etc., are often reviewed by the commissioning agent concurrent with the design engineers. Although the design engineers remain the sole final review authority, the commissioning agent's comments with regards to compliance with the DID are intended to help the designers enforce their specifications.

The commissioning agent will evaluate the construction documentation with one primary objective - to make sure that whatever changes are made do not sacrifice any of the design goals detailed in the DID. Changes are practically inevitable, but if a change will prevent the systems from performing as intended, the commissioning agent will "raise a flag" and initiate discussions with the owner and designers. The owner may choose to accept the change and revise the DID to reflect the modified performance potential, or the owner may decide that he is not willing to give up the original design criteria. In either case, the discussion is held at the time of decision and not after the fact when the owner discovers that he doesn't have the system performance he thought he was getting.

After equipment submittal and shop drawing approval, when the final system configuration and operation is "set," the commissioning agent will revise the draft verification test procedures (included in the commissioning specification section of the contract documents), if necessary, to reflect any approved changes. These test procedures are then distributed to the contractors, designers, and owner for final review, comment, and signoff. By signing off on the procedures, the contractors are agreeing that the systems will be installed and programmed in order to pass the tests. The owner and designers are agreeing that if the systems pass the tests, they will be satisfied that their functional performance requirements will have been met.

Last in sequence of discussion but certainly not least in importance is the need for the commissioning agent to remind all parties of the commissioning process, the owner's commitment to the process, and the seriousness with which the commissioning specification will be enforced. It is always a good idea to have the commissioning agent at the pre-bid meeting to review the commissioning specification section and answer any questions about a potentially new set of requirements.

In addition, the commissioning agent will remain visible during construction by holding periodic commissioning team meetings.  At a minimum the following meetings should be attended by the commissioning agent, design engineers, owner's representatives, general contractor/construction manager, and all contractors whose systems are subject to the commissioning requirements:

  1. Commissioning team kickoff meeting immediately following contract award. This meeting will be to review the specification requirements in detail and to start incorporating the commissioning tasks into the master project schedule.

  2. Meeting to present the final verification test procedures to the contractors for their review and comment.

  3. Detailed test scheduling meeting about 6-8 weeks prior to the start of verification testing.

  4. Pretest kickoff meeting 1 week before testing to work out the last minute coordination and personnel issues.

  5. Post-test status and deficiency resolution meeting immediately following the first round of tests.

  6. Final meeting to confirm operating status of the building systems and to obtain "signoff" from the owner.

In summary, the construction phase commissioning activities are intended to keep the project on track with regards to the final goal of achieving the DID criteria and to plan and prepare for the verification test procedures to be performed at the end of construction.

 

COMMISSIONING: GETTING IT RIGHT

Engineered Systems, April, 1998

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