Consulting-Specifying Engineer - September 2008 - (Page 45)

available for three to five years for a typical building, with months at a time void of activity. Communications skills are crucial, as the CxA must be able to write the Cx document deliverables as well as communicate with every member of the design/construction team. The field CxA will have to write accurate field reports summarizing complex functional issues; one who “doesn’t write” has no place in the project. The CxA must have formal training, although such training (and attendant certification) currently varies considerably in class length and rigor. Evidence of industry involvement in the commissioning community is also important and includes attendance at classes and conferences, and delivery of papers and published articles. Owners should look for a CxA with objectivity. CxAs are often called upon to assess responsibility and confirm correction. They must be able to recommend solutions and confirm correction directly related to quality without prejudicial loyalties to any member of the design/construction team. Their ethical and fiduciary loyalty lies only with the owner. The cast The playbill of each design and construction project includes, but is not limited to, the owner (including the owner’s O&M staff), owner’s representative, architect, engineer, construction manager, general contractor, and subcontractors. Objectively, the CxA can be any one of these entities, or a third-party, independent service provider contracted through any of these units to perform services for the project. Armed with an understanding of Cx requirements, qualifications, and players or delivery methods (listed below), the owner can choose the best combination for the project at hand (see Table 1 for a summary of delivery methods). Independent third party: With this most common delivery method, the CxA can be an architect, engineer, or contractor, but cannot be an employee of, or subcontractor to, the architecture, engineering, or contracting firms already on the project. Alternatively, the CxA can be a completely independent service provider that performs no project design or installation. The independent third-party CxA reports directly to, and is paid directly by, the owner. This provides the least possibility of a conflict of interest on the project at hand (although conflicts can still occur if the CxA is contracted on other projects with the same parties). This arrangement allows responsive, single-point decision-making and action with no loss in translation when information transfers from the CxA to the owner. On the downside, this delivery method adds an additional burden on the owner, who has to manage another project contract. For owners with many projects, this can be a considerable problem. Conflicts of another type arise if the CxA is a design firm and is responsible for checking a competitor’s work, or if it is a contractor checking another contractor’s installation. The independent third-party arrangement can work well, however, when the owner is willing to take the time and energy to monitor the CxA. Project architect or engineer: A CxA within the project architecture or engineering teams will have the best firsthand knowledge of the owner’s design intent and project requirements, since the CxA was part of the earliest project planning. Also, the presence of professional engineers ought to ensure a “systems” approach to the logic behind the HVAC testing process (although, if the engineer is brought on board after all functional aspects have been decided, this might not be the case). On the contrary, if the architect is the CxA, it will have less knowledge of the functioning of the HVAC/MEP systems, which are usually, but not always, the focus of commissioning. The design team likely will have personnel available to commission during construction as that is after their most labor-intensive period prior to bidding. Given that Cx verifies design through plans and specifications checking, a CxA subcontracted or employed by the design team can compromise an honest and thorough critique of the work unless the design firms are large enough to allow separation between departments or offices. This manner of procurement is only partially acceptable for U.S. Green Building Council LEED projects. Using The commissioning process Commissioning (Cx) is defined as the collaborative, quality process of confirming that a building and its subsystems perform in the installed condition as defined by the bid documents and as required by its occupants. This multidisciplinary process engages engineering (namely MEP contracting) and architectural expertise, including the performance of test, adjust, and balance procedures; direct digital control design; installation; and overall project management, demanding the participation of all members of the design, construction, and facilities operation and management teams. In order for Cx to be successful, the following goals must be achieved: • Building and subsystems check: Although Cx is applied primarily to HVAC systems, its application is now spreading to lighting, plumbing, envelope, security, vertical transport, motorized windows, doors and shades, irrigation, and other building systems. • Performance in the installed condition: Cx includes design, submittal, and shop drawing inspection but is inherently an experimental, in-situ testing process. Regardless of the program (USGBC LEED or other), the Cx process is 80% fieldwork. • Performance as defined by the bid documents: The Cx process uses project bid documents, plans, and specifications as guides to judge correct installation. Bid documents lead to shop drawings and, most important, control contractor submittals that define actual systems operation. • Performance as required by the occupants: The process includes a valid owner’s project requirements document and plan specification check, followed by in-situ installation and functional confirmation, leading to a building that operates as required by its occupants. Consulting-Specifying Engineer • SEPTEMBER 2008 45

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Consulting-Specifying Engineer - September 2008 Contents Viewpoint Letters News M/E�Roundtable Selecting Appropriate Egress Strategies Commissioning On-Site Electrical Systems Mentoring Control Engineers and Technicians Casting Call for Cx Case Study New Products Equipment Lifecycles Advertiser Index Green Space

Consulting-Specifying Engineer - September 2008

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