Commissioning Success
Apr 1, 1997 12:00 PM, E. Thomas Lillie, Lillie & Associates
An educational administrator's to-do list is filled with a myriad of responsibilities during a construction project. As engineered systems increase in complexity, administrators often need assistance monitoring the quality of these components and systems.
Although some problems may remain undetected during construction, an array of flaws can exist within the walls of a new facility. Some of these flaws will be discovered soon after the school is opened; others will surface at inopportune moments, creating inconvenient and potentially dangerous circumstances. These problems often include:
Indoor-air-quality concerns. Control systems that do not function properly. An HVAC system that fails to perform during seasonal variations. Warm electrical panels. High humidity buildup within the building. Mold growth.
Providing an alternative Increasingly, schools are retaining, at the beginning of the construction process, an engineer who specializes in commissioning-a form of value engineering and cost control. Commissioning is a project-delivery process that allows administrators to guarantee that major building systems will operate as designed.
The school hires a commissioning agent (CA) to ensure that the design and installation satisfy the intended requirements stated in the contract. With commissioning, administrators can be assured of complete satisfaction-before the contractors leave, before the building is turned over to the maintenance staff and before final payment is made.
Since most of the verification involves mechanical systems, look for a CA who is a professional mechanical engineer. Choose somebody with an extensive background in system design, field construction, construction management and system start-up.
An added benefit to schools is the procedural method of project completion. A comprehensive commissioning plan identifies each step of the process, and delineates a timeline for its completion.
Working together In order to maximize the benefits a CA can bring to a project, and to most effectively orchestrate the commissioning process, involve the CA in the initial planning.
Commissioning can help define expectations and requirements-steps that can guide the process. By establishing, in the beginning, that commissioning will be performed, everyone involved understands their responsibilities.
A CA's initial responsibilities are in conjunction with the designers of the mechanical, electrical, plumbing and life-safety components. During this phase of the project, the CA advises and makes recommendations on the most effective system for the project. CAs do not function as designers; rather, they assist the facility manager in analyzing the proposed design for optimal operation.
At this point, the CA also is developing a list of systems to be included in the commissioning process, establishing design criteria and reviewing construction documents. This information will provide the foundation of the commissioning plan, and the detailed document will include:
A schedule for design documents, submittals, preliminary construction activities, checkouts, testing, startup, turnover and training.
Testing requirements by system for everyone participating in the construction process.
A list of all commissioning documents, including checklists, reports and manuals.
A list of performance-verification criteria developed on a system-by-system basis in accordance with design criteria.
Time to test Once construction has begun, the CA inspects equipment and systems to ensure compliance with the operational requirements. The CA also oversees the functional testing of components and systems, such as pressure testing and control-loop checks. This testing encompasses all modes and sequences of control operation, all interlocks and conditional control responses, and all specified responses to abnormal conditions.
For example, the ability of mechanical systems to perform under partial load is critical, since an inability to perform can lead to high, humid mold growth and air-quality problems. These tests will determine if all components, subsystems, systems and interfaces between systems function properly. Any problems are referred to the appropriate contractor or manufacturer for resolution. The CA continues testing until acceptable parameters have been achieved.
One of the CA's most important responsibilities occurs after installation-the turnover of the systems to the maintenance and operations department. The CA schedules a training session for overall systems operation. These sessions are videotaped for future reference and have detailed, operation and maintenance manuals. Finally, the CA monitors the systems for a set time to verify that they continue to function as specified during seasonal variations.
Delivering value Commissioning can deliver a building that performs-and one that will continue to perform-as expected, but there is cost involved.
The estimated costs for retaining a CA and receiving the full scope of services range from 2 to 5 percent of the total cost of the mechanical, electrical, plumbing and life-safety systems. Not all facilities require a complete commissioning effort, though; system complexity and the scope of the project must be evaluated. At a minimum, HVAC and life-safety systems should be commissioned.
Without commissioning, if the building systems do not function as desired, costly and time-consuming corrective measures may be necessary. It is estimated that fixing a school after it has been occupied will cost four to six times more than ensuring it functions properly in the beginning. In addition, the administrator will be faced with possible litigation or acceptance of a system that may never achieve the desired level of effectiveness.
