Engineered Systems - October 2008 - (Page 28)

Commissioning BY REBECCA ELLIS, P.E. WHY DESIGN–PHASE Commissioning? Get ready for the next time someone asks you. I received a phone call today from an owner’s representative who needs help convincing his client that a commissioning professional should be brought onto the project early in the design phase. The client (building owner) believes commissioning may be a good idea but there is no need to think about it until late in the project — and he meant late in the construction part of the project. This conversation reminded me of how far commissioning has come in the past 20 years, i.e., the owner’s representative is a commissioning advocate because of the benefits he has experienced on past projects. Commissioning now has a history, and that history, for the most part, has resulted in commissioning converts who want to make it “business as usual” for all of their projects. On the other hand, the conversation opened my eyes to the fact that there are still plenty of people — building owners, designers, contractors — who are not as well informed about commissioning as the people with whom I deal everyday. That only makes sense, since I work with those who have already decided that commissioning is valuable and that it is important to initiate the commissioning process during the design phase. I want to use this month’s column to provide some talking points for commissioning converts to use when talking to newcomers to commissioning about why the process should start in the design phase. OWNER’S PROJECT REQUIREMENTS (DESIGN INTENT) The commissioning professional will facilitate the development of a document focused solely on defining the owner’s performance expectations for the new building systems. Clearly defined criteria for temperatures, pressures, IAQ, redundancy, light levels, energy consumption, backup power, etc., are almost never found on projects without commissioning. Facilitating this communication between the owner and the design team is critical in the design phase — as early as possible — to help ensure that the designers’ work will result in systems that meet the owner’s expectations. This is a benefit for the entire project team. O&M PLANNING The commissioning professional will work with the owner’s O&M representatives to define a customized documentation and training program for the new systems. Although turnover of the systems to the O&M staff is an end-of-construction activity, it is critical to have the processes and deliverables clearly defined in the bid documents so that the requirements are enforceable on the owner’s behalf at the end of the job. This process will not necessarily change what the contractors need to provide at the end of construction, but it will clarify how the documentation and training is to be organized, scheduled, and delivered. COMMISSIONING SPECIFICATION If commissioning is intended to be part of the construction phase of a project, it is critical to unambiguously define what that means to the contractors in the bid documents. Without a detailed description of what the contractors need to do as part of the commissioning process, Clearly defined criteria for Clearly defined criteria for temperatures pressures IAQ temperatures, pressures, IAQ, redundancy, light levels, energy edu da cy, gh le els e e consumption backup power etc consumption, backup power, etc., are almost never found on projects are almost never found on projects withou co out commissioning. ss o g and how the systems will be tested and accepted, there will be resistance (e.g., changeorder requests and threatened schedule delays) if commissioning is introduced to the project after the contracts are awarded. COMMISSIONING DESIGN REVIEWS The commissioning professional will be available to review the design drawings and specifications for commissioning-specific issues. One aspect of this review is third-party confirmation that the systems, as designed, should be able to achieve the documented owner’s performance criteria. Equally important, though, is the clarity with which the operational requirements of the systems are communicated to the contractors. Are the control system schematics, points lists, and sequences of operation comprehensive and unambiguous? Are equipment and system interfaces clearly defined? In short, if the commissioning professional cannot decipher what the designers have specified, there may be significant construction-phase issues associated with the contractor making wrong assumptions, inundating the design team with requests for information, and/or asking for changeorders once the designers clarify their expectations. Finally, the commissioning design review will focus on long-term O&M issues. Is sufficient access provided to equipment for PM, repair, and eventual replacement? Are the O&M documentation and training requirements specified in enforceable terms? Even if systems function as intended at the end of construction, the real long-term benefit of commissioning is facilitating the transfer of knowledge to the owner’s O&M staff and creating a base upon which the systems will continue to operate properly long after the design, construction, and commissioning team are off the job. There are still a number of projects where commissioning is introduced during the construction phase, and benefits can be gained even when starting that late. However, every owner who has done that has decided they will begin the commissioning process during the design phase on future projects. These owners are now commissioning converts and will help spread the word to their peers. ES Ellis is president of Questions & Solutions Engineering, Inc. (Chaska, MN). E-mail her at rteesmag@qseng.com. 28 En gi neer ed S y stem s October 2008

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Engineered Systems - October 2008 Contents Editor’s Note Letters Back2Basics HVAC Challenge Case in Point Commissioning Building Automation HydroTech HVACR Designer Tips Special Insert: Engineer's Technical Library Fall 2008 Living Wild! Chilled Beams in Chicago Phoenix Convention Center: On The Rise Cold-Climate HVAC Challenges Humidification Strategies For Data Centers & Network Rooms Special Advertising Supplement: Tabb Talk Computers & Software Issues & Events Products Literature & Catalogs Glossary Classifieds Advertiser Index Tomorrow’s Environment

Engineered Systems - October 2008

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