By Collin Wheeler, Associate
Lead Commissioning Agent
When it comes to construction projects, owners have expectations: how the completed project will look and function, how the budget and schedule will be met, and how each partner will fulfill their individual role in the project. As engineers, we develop the drawings and specifications to meet the owner’s expectations, but there is one variable that is difficult to incorporate into our work: overall system performance.
The entire process of construction and the short time frame in which projects are completed both rely on whether or not the customer’s expectations and the engineer’s intent are carried out as planned by construction managers and numerous subcontractors. When a construction team is mobilized to complete a project, each contractor is singly focused on their own individual task to complete within a deadline. The overall system performance is dependent on depth of understanding the contractors have with their associated equipment and their relationship to the entire building operating system.
Take a simple lab exhaust system, for example. The engineer has drawings and specifications for an exhaust system that includes exhaust fans, dampers and ductwork all controlled by the building automation system, which includes devices such as pressure sensors and damper position switches. It is the engineer’s intent that the exhaust fan will not be able to turn on until the building automation system proves the damper is open, in order to prevent the possibility of collapsing the ductwork. This type of equipment should be easy to install and should work properly by default.
More often than not, however, the commissioning process provided by HAWA discovers that the damper motor operates too slowly, or the switch setting on the damper is not set correctly. It is also possible, in a multiple exhaust fan system, that an exhaust fan being set to turn on is spinning backwards before the building automation system sends power to it. This abrupt change in rotation has a significant impact on the operating life of the electric fan motor and starter. These scenarios are frequently overlooked by installing contractors, because oftentimes their criteria is “did the fan start?”
Commissioning is a crucial process in which we validate and document the performance of the total building and its systems. Verifying that these systems meet the design intent and the owner’s expectations is only part of the commissioning process we do at HAWA. The added value that we bring to each project includes our understanding of the equipment specifications, how each part is being installed, and the holistic knowledge of how all the equipment interfaces together to create a living, breathing building.