By Steve Rizer
What are some of the tools that can be used to assess a building’s current energy consumption? What is the best strategy for measuring and addressing air leakage in a building envelope? These were among the questions that Triple Green Building Group Principal Kelly Gearhart answered during the “Q&A” segment of “Energy Efficiency for Existing Buildings,” a WPL Publishing webinar for which a recording recently was added to the ConstructionPro Network (ConstructionProNet.com) Download Library -- free of charge for members.
In response to the question about assessment tools, Gearhart said, “Well, I think, depending on the kind of building it is, one of the best places to start is EnergyStar.gov. There’s a program there called Portfolio Manager, and, if you have an existing facility, it’s really easy to go in there and put in your energy bills for the last 12 months or so, … give it your zip code and give it some information about occupancy. You can even get into more detail and tell it how many PCs or computers are running in the building. There’s some basic data about the space types, whether you have a chunk of office occupancy, a chunk of retail occupancy, and so on.”
From there, the website will “spin its wheels and then compare your energy use intensity to buildings that are like you and score you on a scale of zero to 100,” Gearhart explained. “That scale, if you hit 50, … means you are right in the middle of the pack with your energy use intensity with your building type normalized against the data from buildings across the country. If you’re at 75 or higher, you’re actually doing quite well, and you are eligible to earn the Energy Star for your building. So, I would suggest that as a starting point.”
Answering the question about air leakage, Gearhart said, “There are service providers out there who will do a few things. There [are] a couple of strategies. You can do pressure testing, of course, in an existing facility. You’re basically pressurizing the building and seeing how well it holds on to that pressure. You can also get some … infra-red scanners -- infrared detectors -- and you can actually take images of the outside of the building and see where heat is being lost or where cool is being lost on the exterior of the building with a color indicator. So, those are a couple of strategies to measure air leakage, and once you’ve recognized where those leaks are in the building envelope or that you have a leakage problem, you can then improve upon it from there with the right kind of sealant and the right kind of verification that it’s been done well.”
Another webinar attendee asked whether buildings within the Living Building Challenge, which the International Living Future Institute described as “a green building certification program that defines the most advanced measure of sustainability in the built environment possible today,” are achieving net-zero goals.
“The answer to that is ‘Yes,’” Gearhart reported. “In fact, one of the buildings … covered in the Greening Our Built World book by Greg Kats and his associates is net-zero.”
Specifically, Gearhart pointed to the Aldo Leopold Center, which produces an estimated 113 percent of the energy needed for their facility. The 12,000-square-foot center is certified as Leadership in Energy and Environmental Building Platinum, having garnered 61 of 69 possible points. The structure uses an estimated 70 percent less energy than a typical building of its size and draws upon a suite of onsite renewable energy systems. More information about the Leopold Center can be accessed at http://www.aldoleopold.org/visit/leopoldcenter.shtml.
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