Commissioning Engineered Building Systems: Scope Enhancement

By George Bourassa, P.E., LEED AP, Senior Vice President and National Director of Commissioning, Facilities Division, Carter & Burgess, Inc., Chicago April 28, 2005
Last month we looked at some of the benefits of commissioning for building owners and for contractors and subcontractor members of the project team. This month, let’s take a look at the breadth of scope.

Commissioning has been a formally recognized practice in project delivery for about a decade, and based on successful results, the breadth of scope in application of the commissioning process continues to increase.

ASHRAE’s published definition of commissioning is: “A quality-focused process for enhancing the delivery of a project. The process focuses on verifying and documenting that the facility and all of its systems and assemblies are planned, designed, installed, tested, operated and maintained to meet the Owner’s Project Requirements.”

It is appropriate that ASHRAE has helped define commissioning, because the practice really started with a focus on HVAC systems. As the most dynamic systems in a building, with operational impact that building occupants are most sensitive to, HVAC systems were a logical place for the commissioning process to concentrate. Based on demonstrating the performance verification of these initial systems, the scope of commissioning has grown significantly, as more building systems are interfacing and technology advancements are being incorporated into virtually all building systems.

Further, when owners realized the success of commissioning related to efficient operation of HVAC systems, they legitimately concluded that the process could be applied to other building system performance verification just as effectively.

As Owners are evaluating the scope of commissioning for a building project, I advise them that, when appropriate, commissioning of the HVAC system only may not be most cost effective in a modern building, especially one that is targeted for “high performance” and the U.S. Green Building Council’s LEED certification.

The HVAC system interfaces with emergency generators, fire protection and multiple other systems, so that a deficiency in performance from any of the systems could lead to unexpected and negative situations. HVAC systems are becoming significantly more sophisticated because they are being designed to comply with numerous diverse expectations. There is the environmental/air quality issue, of course, the energy issue, the building space issue, the operational maintenance issue and the long-term life cycle reliability issue. When you overlap these parameters, along with less onerous supplementary expectati0ons, a daunting demand for performance is attached to these systems.

As a consequence, the building operations community is being challenged to stay abreast of the technology and expectations. For example, consider the energy budget expectations for HVAC systems. More and more design teams and owners are developing energy budgets associated with a specific building design, in part because owners need to budget for the life cycle cost over the long term. There is increasing awareness that building life-cycle costs are dominated by operating expenses and capital costs represent a minority of the overall pie.

When setting up an energy budget, the owner wants confidence that the system will meet the performance criteria from initial operation. If systems are not performing efficiently from the start, there is a likelihood that the life cycle budget will be exceeded and the financial consequences are profound, especially in light of utility contract demand ratcheting and escalation.

The success of HVAC systems commissioning has contributed to the evolution of the practice. Commissioning now covers a whole array of systems within a building, even to the point where we are now doing the building envelope as part of the commissioning process. The term that has been adopted for this type of commissioning is “whole building commissioning” and it has increased in popularity across the country in the past few years.

The ASHRAE definition covers the basic goal of commissioning, but the scope and timing of commissioning are decisions that the hiring authority has to make and can vary from project to project.

In fact, commissioning is applicable to other types of projects as well. For example, at an airport, the aircraft de-icing system is a candidate for commissioning, as are the aircraft taxiway monitoring systems. Any project that incorporates a process or interaction of multiple systems, for example, a water treatment plant, is a candidate for commissioning.

In the pharmaceutical industry, there is a process referenced as verification that is a higher level of commissioning applicable to processes, independent of building systems.

The transportation industry has a whole array of opportunities for commissioning, from switching systems to systems for collecting fares and highway monitoring.

In the past few years, the scope of commissioning has expanded tremendously, as more owners and facility managers are recognizing that the process has been successful and that it can be taken to other opportunities. It is my opinion that we have only scratched the surface of not only building commissioning, but project commissioning as well.

That said, a typical building commissioning project today would likely involve a composite of HVAC, electrical (normal and emergency power), security, fire protection and controls/building automation systems. Those evaluating the incorporation of commissioning into their building projects need to consider how comfortable they will be if their HVAC system is working to the performance level expected, but when the first power failure occurs, the emergency generators don’t start. Aside from the fact that the HVAC system will not be functioning in this circumstance, the interfaces with your fire alarm and security systems and other critical building systems will have been lost as well.

One can quickly appreciate that commissioning is becoming more vital as building systems become more technologically advanced.