Facility Managers' Grasp Of Big-Picture Issues Is Crucial To Net-Zero Performance
Facility managers' grasp of such big-picture issues as a building's hours of operation and the right size for its equipment is crucial to energy performance.
Take for instance Turkey Foot Middle School — a 134,000-square-foot facility located in Edgewood, Ky. As the building programming was in progress, Rob Haney and his facilities team interviewed coaches, teachers, and other building users "to try to anticipate and predict the hours of operations to the best of our abilities," says Haney, who is executive director of support operations for the Kenton County School District. Often, when a building opens, and it winds up using more energy than it was modeled to use, the reason is not that it's a bad building with major faults; it's simply that it's operated at different or more hours than designers assumed. So it's critical to get as accurate an idea as possible about the actual hours of operations, not just make assumptions based on rules of thumb.
Today, four years after opening, Turkey Foot operates at an EUI of 24 — well below the mid-70s average for schools in its district, say Haney. What's more, it was built for a cost of $175.59 per square foot. Compare that to the average cost of comparable schools in the region of $195.59. The district also received a 50/50 grant from stimulus funds for a solar array that brings its net EUI down to 11.5 (the cost with the solar array and including the grant money is $185.72 per square foot). Adding more solar could get Turkey Foot to true net-zero energy — "we're within striking distance," says Haney. And eventually that's a goal, but Haney says the challenge is that there are other capital construction priorities in the district. Haney says the annual energy bill at Turkey Foot is currently $30,000 per year, which compares to more than $100,000 in the previous middle school building that was double the floor space.
Another way in which facility managers' expertise on real-world operations is critical is in terms of right-sizing equipment to match the way the building will be operated. Most facility managers aren't mechanical engineers, but they're well familiar with the tendency of some engineers to err on the side of "bigger is safer" in terms of designing equipment. They're also familiar with the idea that over-sizing equipment wastes energy in operations. This can't happen in any facet of a building when attempting to squeeze energy use down to single-digit EUIs. There's simply no margin for error.
At DPR Construction's new 19,000-square-foot regional office in Phoenix, which the company occupied in 2011, and which has been certified net-zero energy by the Living Buildings Institute, intense scrutiny on HVAC equipment efficiency, and balancing that figure with the amount of renewable energy it could expect to generate with a solar array, has allowed it to get to net-zero energy.
"We were the worst customer we've ever had," jokes Dave Elrod, regional manager for DPR, on the design meetings for the facility. "We didn't just throw a bunch of money at a big PV system. We sized it for the load we expected to use."
In DPR's case, the front-end discussions regarding SEER 18 package units (which didn't make it) and PV systems (which did) wound up bearing fruit. In the first year of operation, the facility wound up with about two weeks of energy surplus — meaning it had met its net-zero energy goals by the slimmest of margins. And it was even slimmer in the second year, says Elrod. Having now been on both sides of the proverbial table as a designer/builder and an owner, Elrod says he recognizes how important it is for the facility manager to be involved early in design, not only for reasons of expertise, but also because it's the facility manager who gets the bill.
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