It’s 10 p.m. Do you know what your building is doing?
By Lincoln Pearce, PE, LEED AP, BEAP
IMEG Senior Principal
Some of you may remember that old public service announcement before the evening news, asking if you knew the whereabouts of your children. In a way, the same thought applies to the performance of your building. It’s 10 p.m. – are the lights on? Are the HVAC systems on? Have the temperature set points been set back? For many buildings, the answers to these questions aren’t what they should be – and are likely causing building owners a lot of money.
When retro-commissioning or evaluating a building’s energy consumption, our commissioning team commonly discovers incorrect operating schedules causing systems to operate when they shouldn’t. You don’t park your car and leave it running with the keys in it for long – and the same philosophy should be applied to the operation of your facility. Like running your car unnecessarily, running your building’s systems at unnecessary levels wastes energy and results in added operational and maintenance costs. How much can be saved by having a properly performing infrastructure? A 2009 study by the Department of Energy’s Berkeley Lab reported that retro-commissioning results in a median whole building energy savings of 16 percent. That’s a significant savings.
In the 10 years since the Berkeley Lab’s study, energy use reduction has only grown in importance, and today the building design and construction industry is trending toward more monitoring of a building’s performance after construction is complete. Ongoing commissioning, measurement and verification, and fault detection diagnostics are becoming more common activities after occupancy, acting on the adage that you can’t manage what you don’t measure.
There’s great value in this holistic approach from concept to consumption because it closes the loop between design intent and actual performance. In addition, high-performance and sustainable design projects often bring a higher level of system complexity, and as such a greater chance that systems may not be operating as intended. If they aren’t, the building is not realizing the performance savings expected during design
A great example of what can be achieved is the post occupancy measurement and verification work IMEG conducted following the recent Marston Hall renovation at Iowa State University. Monitoring of the building’s energy use for a year after the renovation showed the facility was using 41% more energy than we had modeled during design. Was our modeling off or was there an issue in the operation? It turned out to be an operational issue, and rectifying it is saving the university a substantial amount in energy use and costs. Read more about the project – and how we identified and fixed the culprit – in an article published by C-SE magazine.