Most people in the major design and construction business understand that commissioning is a process by which a building’s systems are verified to function properly prior to acceptance by the owner. However, design engineers, architects, and contractors tend to be less aware of the intent for commissioning to help set the stage for continued proper operation of the systems for the life of the building. Building owners value this second objective at least as much as the first.
Requirements for sustainable operations include, but are not limited to, accurate, complete and timely systems documentation, meaningful maintenance training, customized systems operations training, and access to equipment for regular maintenance and repair.
For example, if we cannot find or reach a filter differential pressure switch to confirm its installation and document its set point, what will happen when one of the tubes slips off the switch and the reading on the control system graphic becomes meaningless? If the maintenance technician cannot physically access the switch to reinstall the tube, the helpful data it provides regarding filter condition will be lost.
Similarly, if we cannot see, much less reach, a damper or valve actuator to confirm its response to control system output signals, how is a maintenance technician to repair the actuator when it fails (which it will inevitably do at some time during the life of the system)?
If we cannot open the access doors on the side of an air handing unit to observe the condition of the filters, dampers, coils, fans, etc., how will the maintenance staff be able to do their jobs?
These are things that a seasoned commissioning professional will think about intuitively. We are looking for accessibility, starting in the design phase and continuing through construction. It is a major focus of our construction-phase site observations. Early in design is the easiest time to correct an equipment access challenge. Even with BIM technology and conscientious design/construction planning, access issues continue to present themselves during construction. When they do, the issues tend to be more about coordination between trades than about the mechanical or electrical contractor installing the equipment in the wrong place.
I was involved in a recent project where commissioning was not introduced until the design was complete and the building well under construction. It was explained to me that the design team did everything in BIM and it was all carefully coordinated. In hindsight, the “coordination” seems to have been limited to the ability to fit everything into the allotted space without necessarily considering service clearance areas, paths to reach the equipment, or safe platforms for service personnel.
The design engineers had disengaged from the project by the time commissioning kicked off, and the contractors would not deviate from the design documents for fear of being liable for the results of any unauthorized changes. When the commissioning professional discovered nearly impossible physical access conditions during construction, the project team response varied depending on the impact of the potential solution.
If the solution simply required more money without negatively impacting the project schedule, we eventually worked through some modifications. If there were no simple solutions that could be implemented without impeding construction progress, the project team chose not to address the acute equipment access problems. As a result, the first thing the owner is doing after turnover of the new systems is developing projects for correcting the access issues. This will cost the owner far more money than correcting the situation earlier in the project, but the building opened on schedule and that was a higher priority during construction.
The owner understands it is important that every one of these inaccessible pieces of equipment remain operational. If it were not important, the equipment would not have been installed in the first place. The owner also understands that every sensor, device, and moving piece of equipment will eventually fail, and every unchanged filter will eventually fill with dirt and stop airflow. The key to the post-construction rectification projects will be to complete them before the inaccessible equipment grinds to a halt. ES