Building commissioning – is it really worth it?Peter Serian for Zondits, November 3, 2014
As energy efficiency programs strive to transform the market with new technologies and systems, building commissioning remains one of the most ripe and undervalued opportunities. Commissioning and its various forms, which include re-commissioning, retro-commissioning, and continuous commissioning, ensure that the systems in a building are operating as efficiently as possible. Commissioning applies to a host of building end uses, including HVAC, refrigeration, lighting, and controls. Without commissioning of these systems, the incremental benefits of the most efficient equipment can be lost.
So what is commissioning exactly? Both ASHRAE Standard 202-201, ASHRAE Standard 202-2013, The Commissioning Process for Buildings and Systems, and ASHRAE Guideline 0, The Commissioning Process define commissioning as “a quality-focused process for enhancing the delivery of a project. The process focuses upon verifying and documenting that all of the commissioned systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the Owner’s Project Requirements.”
The benefits of properly commissioning a system are vast. According to the National Institute of Building Sciences, the benefits of commissioning a building include a safe and healthy facility, optimized energy use within a building, reduced operating costs, staff training on proper O&M practices, and improved documentation of building systems. What does this all boil down to? A finely tuned, energy efficient building that operates as originally designed.
Understanding the different types of commissioning can be tricky. Commissioning a building that was previously commissioned when construction was complete is called “re-commissioning.” “Retro-commissioning” is commissioning a building that was not commissioned when construction was complete. A newer practice that is gaining momentum is “monitoring-based” or “continuous commissioning.” Where re-commissioning and retro-commissioning are done at a discrete point in time, continuous commissioning is the ongoing collection and analysis of building system data. The data, typically provided by building automation systems (BAS) or energy management systems (EMS), is continuously monitored to determine when building performance deviates from optimal.
So why aren’t building owners clamoring to their have new and existing buildings commissioned? Estimates to commission a new building come in at 0.5% to 1.5% of the total cost of the project. According to the EPA, retro-commissioning costs can range from $0.05 to $0.40 per square foot. The incremental cost of commissioning results in building owners questioning the value of paying a consultant to complete a task that installation contractors should include in their original service. The reality is that installation contractors are great at installing systems but not necessarily at making sure they operate as efficiently as possible. The value of a commissioning agent is highlighted by Lawrence Berkeley National Laboratory (LBNL) in the following cartoon.
Besides the inherent deficiencies in the construction process, LBNL completed a study in 2009 that provides evidence of the economic benefit of commissioning. The LBL study gathered and analyzed data on 643 buildings, representing 99 million square feet of floor space from 26 states. The study found median payback times of 1.1 and 4.2 years for existing building and new construction, respectively. What’s more, the energy-savings potential of retro-commissioning in the existing non-residential buildings in the U.S. is as much as $30 billion per year by 2030.
Building commissioning does pay off, and it’s imperative that as we look for savings opportunities in existing buildings and design and build the next generation of new buildings, commissioning and all its forms are part of the equation.
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