Possibly one of the most underappreciated ways to achieve improved efficiency in buildings is not a technology, a system or a gadget. Commissioning and its variants (re-commissioning, retro-commissioning, ongoing commissioning and continuous commissioning) are among the best ways to ensure that building systems are operating as efficiently and effectively as they can be. To put it another way, commissioning can help assure building owners that they’re getting the best return from the tens of millions of dollars of capital they’ve invested in their buildings’ systems.
In its Guideline 0, The Commissioning Process, the American Society of Heating Refrigeration Air-Conditioning Engineers (ASHRAE) defines commissioning as “a quality-oriented process for achieving, verifying, and documenting that the performance of facilities, systems, and assemblies meets defined objectives and criteria.” The most commonly commissioned systems are HVAC and refrigeration systems and controls, lighting controls, domestic hot water and renewable energy.
The National Institute of Building Sciences provides a great summary of commissioning’s benefits and processes here. It summarizes the benefits as follows: “Commissioning assists in the delivery of a project that provides a safe and healthful facility, optimizes energy use, reduces operating costs, ensures adequate O&M staff orientation and training, and improves installed building systems documentation.”
Though the commissioning function has been around for a long time, and probably not even originally called commissioning, the USGBC’s LEED rating system has greatly increased its visibility and demand for these kinds of services. The New Construction, Commercial Interiors and Core & Shell LEED rating systems all include “Fundamental Commissioning” as a Prerequisite, meaning it is required for any project seeking LEED certification. There are also additional points available for “Enhanced Commissioning,” getting the commissioning agent involved in the process earlier and re-visiting some of the issues once the project is complete. Commissioning plays an even larger role in the Existing Buildings:Operations & Maintenance system. EBOM also includes points for “Ongoing Commissioning,” with the intent of making “periodic adjustments and reviews of building operating systems and procedures essential for optimal energy efficiency and service provision.”
Commissioning in an existing building is “re-commissioning” if the building systems had previously been commissioned when construction was completed, or “retro-commissioning” if the building had never been commissioned before. Re-commissioning is known to provide significant benefits as operating conditions and practices could have changed quite a bit over time. Often, this is simply due to changeover in operating staff, though it also could be that staff has taken it upon itself to make adjustments, for expediency or otherwise, that aren’t in the best interests of optimal overall operation.
Why doesn’t everyone commission and retro-commission and then re-commission again? The number one reason would be cost. There are estimates that commissioning can add from 0.5% to 1.5% to the total cost of a new construction project. It’s easy to see how there would be reluctance to paying so much to a consultant for apparently just confirming that the other contractors and sub-contractors did what they’re supposed to do. This is an over-simplification of the commissioning agent’s role, however. It is often the commissioning agent who makes sure early on that the various contractors and their activities are properly coordinated in the first place. In case you’re not familiar with the classic tree swing construction program drawings, illustrating the potential value of a commissioning agent, check them out here.
Moreover, there are important studies showing that commissioning pays off in real dollars. The major 2009 study by Lawrence Berkeley National Laboratory titled “Building Commissioning: A Golden Opportunity for Reducing Energy Costs and Greenhouse-gas Emissions” provides some great evidence. The data was from 643 buildings representing 99 million square feet of floor space. Here are some of the findings.
And don’t miss LBL’s Hall of Shame photographs showing some amazing energy-wasting situations.
Commenting on the LBL study, ASHRAE President William A. Harrison pointed out that the reduction in energy use due to commissioning was “not so much the result of changes in hardware and systems as it was the result of improvements in software and expert knowledge.”
As if the paybacks aren’t attractive enough, retro-commissioning is often financially supported by energy efficiency programs run by utilities or state agencies. In New York, for example, NYSERDA provides cost-shared assistance for retro-commissioning investigations. In Illinois, ComEd’s Smart Ideas for Your Business program provides free retro-commissioning analysis to eligible businesses.
A relatively newer practice within the field is known as automated or monitoring-based or data-based commissioning. Texas A&M’s Energy Systems Lab has trademarked another even more commonly used term, “Continuous Commissioning.” The key difference from retro-commissioning, which is done at certain point in time, is that Continuous Commissioning is based on the ongoing collection and then analysis of energy data. This data is usually supplied by an existing building-automation system (BAS) or building energy management system (BEMS), though it’s possible to used dedicated meters and sensors. The systems are monitored and compared to desired performance levels on a continuous basis. Out of bounds readings are quickly flagged and investigated.
The LBL study projects that 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. In addition it estimates that this work could provide approximately 24,000 jobs in a $4 billion per year industry. This potential hasn’t gone unnoticed. Membership in the Building Commissioning Association is up from 500 in 2005 to 2,000 today. BCA also reports that interest in their certification program is up by 30%.
Savings opportunity. Business opportunity. The potential is out there and it’s big.