はじめに「試運転調整とコミッショニングの機能性能試験に関する米国と日本の違い」 ～　ハワイ会員　Ryan Chang 氏の投稿記事の前説として　～ をご参照ください。

While performing commissioning at a job site, I sometimes get asked what is the difference between testing, adjusting, and balancing (TAB) and commissioning (Cx). Both activities seem to focus on fine tuning the operation of heating, ventilating, and air conditioning (HVAC) systems and verifying the correct performance of the energy management and temperature controls. By performing both, do you expect to duplicate the effort, contractor’s cost, and end with the same results? Although there is some overlap between the two procedures, they are very different because of their objectives. The intent of this article is to summarize the differences between TAB and commissioning.

By definition, TAB is the testing, adjusting, and balancing of HVAC systems, which can also sometimes include testing of refrigeration and plumbing systems. An HVAC system that has been properly designed and constructed still requires balancing adjustments in order to provide a comfortable, safe, healthy, and productive environment. TAB activities are performed during the construction phase of a renovation or new construction project. Whereas commissioning has both design phase and construction phase activities, which depend on the Owner’s project requirements for the commissioning scope of work.

Commissioning is a quality focused process for enhancing the delivery of a project. During the design phase, the Owner is given the opportunity to define the goals for the commissioning process to achieve. This may include energy efficiency goals, sustainability, ease of maintenance, construction budget, project schedule, completion date, User requirements, any other Owner directives. The commissioning agent integrates these objectives into the Owner’s Project Requirements (OPR) document, which is used as a guide to develop the design drawings and specifications. The commissioning agent must also provide a commissioning plan that captures the Owner’s minimum criteria and goals for the project to be considered a success.

Another difference between the two professions is that TAB is performed primarily on HVAC systems. Since the beginning, Commissioning of new building construction was checking the HVAC equipment and control systems. Commissioning has now evolved to include many other building systems that the Owner desires to be checked. The Owner may request the commissioning agent to test the plumbing, fire protection, fire alarm, vertical transportation, electrical, communications, building envelope, and medical gas systems. A pre-functional test (PFT) and functional performance test (FPT) can be written for any building system that has a sequence of operation if the Owner desires those systems to be commissioned.

The following two lists summarize the typical roles and responsibilities that TAB and commissioning firms must provide on a typical new building or renovation project. I would like to clarify that construction projects in America, including construction projects on U.S. military defense bases outside of America, the TAB contractor is usually required to be certified by one of the TAB licensing organizations (AABC, NEBB, TABB, or others). These certification programs often require the TAB contractor to perform additional services such as design reviews, reporting design/construction/TAB problems, and providing certified test reports. These services are typically not required on non-U.S. projects.
The role of the testing, adjusting, balancing contractor usually includes the following:

・To review the design to identify any design deficiencies that would prevent the TAB company from successfully balancing the HVAC systems.
・To perform duct air leakage testing (DALT) to demonstrate that the contractor has adequately sealed the distribution ducts systems.
・To perform the testing, adjusting and balancing (TAB) and balance all airflows, water flows, and equipment to match the design quantities.
・To own and maintain a complete set of calibrated TAB instruments that are necessary for performing an accurate balance of the air and water distribution systems.
・To conduct a peak cooling test and a peak heating test to confirm the systems can deliver the design cooling and heating capacities under maximum seasonal conditions.
・To report any design or construction deficiencies that are found during the TAB process that affect the overall operation of the HVAC equipment and control systems.

The role of the commissioning agent usually includes the following:
・Assisting the Owner to develop the Owner’s Project Requirements document at the start of the design phase.
・Identify all equipment, systems, and modes of operation of systems to be commissioned.
・Review the design to define how is the building equipment and systems are supposed to operate. If any design information is missing, the information is requested from the A-E designer.
・Develop a commissioning plan that specifies the systems to be commissioned, parties involved in the commissioning process, commissioning test procedures, methodology for resolving problems.
・Develop PFT and FPT checklists based on the designer’s intent and the Owner’s project requirements.
・Conduct field inspections, PFT, and FPT to document the correct installation and operation of the systems.
・To create and manage the issue log that keeps track of problems found during commissioning and ensures that all problems get resolved before the end of the project.
・Verify the contractor’s training plan contains adequate information for the Owner to understand how to maintain the systems after the building handover.
・Verify that the contractor’s training plan includes a list of all the equipment manufacturers and the installation contractor’s contact information if future help is needed.
・Provide a commissioning report that documents the end results and recommendations that explain the overall commissioning project.
・For Enhanced Commissioning, the commissioning agent may also develop a plan for ongoing commissioning that focuses on maintaining the building’s systems during its occupancy.

Another difference between TAB and Cx is that commissioning requires cooperation and communication between the Owner, Users, construction managers, design architect, engineers, construction contractor, and subcontractors to deliver results. Commissioning is a team effort that requires all parties understand that we have a set of common goals for the project. Everyone wants the project to go well, the building systems to be working perfectly, debugged of problems, construction to be completed on time, and within the allowable budget. None of the parties are hoping that design or construction flaws are found during the final days before the handover date. These problems can add time and expenses to a project that can reduce the owner’s or the contractor’s budget. The goal of commissioning focuses on identifying problems to make corrections as early as possible to find cost-effective solutions ahead of the completion date. When all parties share this responsibility, they are working together toward a common goal. The end result of a successful commissioning project is a quality building that all of the parties can be proud of.