Q: I’m now hearing a lot about “ongoing commissioning” and “continuous commissioning” of facilities. Can you clear up my understanding of the various types of commissioning and the role each plays in today’s built environments?
A: “I can see clearly now, the rain is gone, I can see all obstacles in my way…..” Johnny Nash, 1972
When Johnny Nash penned these lyrics, the world was a different place—and the controlled environments we know today have gone through almost as many iterations as Nash’s original song.
The goal of building commissioning (Cx)—in whatever form or building stage it’s performed—is to clearly identify and rectify obstacles to the efficient operation of buildings. First, a quick refresher. Then we’ll review some recommended best practices for building commissioning and provide you with sources for more detailed information than this column can cover.
Commissioning 101
Building commissioning is a relatively young practice, first integrated in the project delivery system by Public Works Canada in 1977. Notably, Disney included Cx in the design and construction of the Epcot Center in 1981, and three years later the University of Wisconsin, Madison began offering Cx courses. Relatively speaking, the last few years have brought an explosion of commissioning practices and process refinements, partially enabled by increasingly sophisticated equipment and greater demand by commercial building owners. The increased adoption recently of building commissioning can also be credited to the significant cost savings building owners have enjoyed, with relatively quick returns on their investment.
ASHRAE Guideline 0, The Commissioning Process, defines building commissioning as “a quality-oriented process for achieving, verifying, and documenting that the performance of facilities, systems, and assemblies meets defined objectives and criteria.” It’s all about building performance and quality assurance: making sure a building is operating as intended by the designers and engineers, and that the building staff is able to maintain the efficient operations of the equipment and systems.
In a perfect world of new construction, that seems straightforward enough. But new buildings and their systems age; while additions, renovations, and changing uses deteriorate the functionality of the building’s operating systems. Decreased efficiency, increased operating costs, and reduced life cycles of capital equipment result. So, to remedy these situations, below are a few more key definitions of Cx processes you should understand:
The Building Commissioning Association (BCA) defines existing building commissioning (EBCx) as “a systematic process for investigating, analyzing, and optimizing the performance of building systems through the identification and implementation of low/no cost and capital-intensive facility improvement measures and ensuring their continued performance.” EBCx could be considered an “umbrella term” defining in the broadest possible way any Cx processes involving an existing building. But here are three important sub-categories to keep in mind:
• Re-commissioning refers to the process of commissioning a building that has been previously commissioned. While recommendations as to how frequently the re-commissioning process should be undertaken are dependent upon a host of factors, Energy Star recommends re-commissioning be undertaken every three to five years.
• Retro-commissioning is a term used to define the commissioning of an existing building that had never been previously commissioned. The goal of retro-commissioning, in alignment with Cx practices generally, is to improve the functionality of a building’s systems and equipment. These improvements could address problems that are caused not only by declining systems functioning, but also redress issues that may be the result of changing use, design, and construction.
• Ongoing commissioning (a/k/a continuous commissioning) is a variant of re-commissioning but is, literally, an ongoing process enabled by the development of monitoring equipment and sophisticated software that allow the building’s systems to be continuously monitored. The equipment and analytic software are connected to the building’s systems which enable usage, performance, and trending data to be fed continually to quickly identify any variation in building system performance.
In short, a “continuous” building commissioning program is data based. The program constantly monitors a building’s system performance (usually HVAC) through automated building control systems, and then analyzes and compares the data to analytical models. This allows a facilities staff to identify problematic equipment, including controls and sensors.
Interestingly, the term Continuous Commissioning was trademarked by the Energy Systems Laboratory (ESL), a member of the Texas A&M University System, although the term appears to have gained widespread, popular use.
Don’t get hung up on terminology. The process of commissioning, regardless of when it’s applied, is aimed at the same end goals: optimizing energy use while improving comfort, reducing costs, and solving building operations issues. And don’t forget the benefit of avoiding an “unhealthy building” crisis. You’re simply keeping your building tuned up, much like you take care of your car.
Where’s the payback?
There was once a famous commercial for a hamburger chain where an elderly lady goaded a competing burger chain for the puny sized hamburgers they served by asking, “Where’s the beef?” Today’s facilities professionals want to know, “Where’s the payback?”
Compared to even a few years ago, metrics are now mainstream and more reliable. Tools, including building simulation and energy modeling, building management systems, computational fluid dynamics (CFD), energy monitoring and building systems software and others, all feed into the increasing reliability of data. Fault detection and diagnostics software allows building operations and equipment performance to be monitored against ideal operations in virtually real time, providing information on performance and identifying potential problems with the building systems themselves in addition to energy consumption. This explosion of data driven knowledge allows facilities professionals to understand both real costs and avoided costs to a degree not possible before— not only in developing estimates for a new building but in being able to measure relative performance throughout the life cycle of an existing structure.
This enables more sophisticated design of building systems, with goals for future savings, reduced energy consumption and footprint, the comfort of the occupants, and more efficient maintenance programs to be met. Increasingly a building’s major systems—such as electrical, HVAC, plumbing, and even structural components—are being designed in coordination with an eye to these goals.
While the avoided costs and payback to investment realized from undertaking building commissioning will vary greatly due to building type, Cx program, and location, building commissioning is now widely recognized as providing both significant and swift returns on investment. Below is an example published by the Massachusetts Institute of Technology, which has undertaken an ongoing commissioning program:
“Building 68 served as a pilot site for the program, in which it was determined through detailed monitoring of the building automation system that heating and cooling were occurring simultaneously in three large air-handling units. Programming changes were then applied to the buildings automation system, reducing both steam and chilled water consumption immediately and creating an annual savings of more than $360,000 in that building alone. Based on these successful results, MIT has applied its continuous commissioning program on some of its most energy-intensive lab buildings. To date, the buildings commissioned by this method include Dreyfus (18), Zesiger Center (W35), Koch Biology (68), new Ashdown (NW35), Dorrance (16), and Whitaker (56) and Whitaker College (E25) Continuous commissioning is also being incorporated into new construction. MIT has committed $850,000 to this multiphase commissioning program and expects to save $847,000 annually in energy costs.” Source: MIT Energy Initiative (www.mitei.mit.edu)
What’s coming in Part 2
“The Building Commissioning Maze, Part 2” will be in the next (April) issue. In that column, we’ll continue the discussion on commissioning including some basic rules for the road and 13 key steps to undertake in any commissioning process.
Richard Bilodeau, PE, is director of engineering at SMRT, architects and engineers (www.smrtinc.com). His 30 year career includes plant engineering positions in clean manufacturing. Richard has engineered, designed, operated, and supervised the construction of numerous controlled environments and labs for advanced technology, life sciences, industrial, healthcare, academic and corporate clients. Dick can be reached at [email protected] or [email protected]
This article appeared in the March 2014 issue of Controlled Environments.
