October 24, 2017 07:48 PM
Duluth's high schools have gotten some good grades when it comes to energy.
Both Denfeld and East recently earned Energy Star certifications. East scored in the 98th percentile, Denfeld in the 97th.
"Energy Star benchmarking is a tool developed by the Environmental Protection Agency to judge the performance of a building against a similar building," Kris Spenningsby, Minnesota Power retail accounts supervisor, said. "So in the case of the Duluth schools, they performed better than 98 and 97 percent of other high schools out there."
This is something the facilities team has been working toward for about a decade.
"I was really excited," Facilities Manager Dave Spooner said. "In fact, when I saw that this school had scored so high, I thought maybe there was an error. But it was true."
Spooner said he is very proud. Adjustments have been made both on a small and large scale to make the buildings more energy efficient.
"As soon as people come in the room, the ventilation starts, the lights come on," Spooner said about the individual classrooms. "And vice versa if people leave the room."
In classrooms with a lot of windows, there are also sensors that dim the row of lights closest to the natural light. Even the ventilation is based on use.
"In the ductwork, there's carbon dioxide sensors. So if you have a lot of people in a room, it's going to sense that (the fan) needs to speed up," Spooner said.
Minnesota Power has partnered with the district for many years to assess ways they can be more energy efficient.
"Oftentimes, more energy efficient devices are more expensive," Spenningsby said. "So we're able to offer rebates to close that difference in price."
Overall, Spooner said the energy upgrades pay for themselves.
"It helps us conserve energy, it's being good stewards of taxpayer funds," Spooner said. "It makes it a really conducive teaching and learning environment in the classrooms."
In fact, in 2007, it cost the district $1.04 per square foot per year for all of what was then Ordean's utilities. Ordean was about a third of the size of East. In 2017, it cost .62 cents per square foot for East's utilities.
"The district has saved a considerable amount of money than we would have if we hadn't done this plan," Spooner said.
At East High School, they used to have two giant boilers that were only 60 percent efficient. Now, there are five high efficiency condensing boilers that are 90 percent efficient. On a day like Tuesday, only two of them needed to be running. But if it was a -40 day in the dead of January, all five would kick in.
From the outside in, they prepped East and Denfeld to keep heat and AC in.
"We specified high efficient glass and windows and skylights, high efficient insulation for our roofs and our walls," Spooner said. "So if the building envelope is good, then that's a major player for energy efficiency."
That's part of the overall plan, which Minnesota Power helped with.
"Energy conservation's an important part of Minnesota Power's long-term Energy Forward strategy to provide clean, safe and renewable energy to our customers," Spenningsby said.
For Spooner, the Energy Star certification is a big accomplishment.
"I'm very proud of that," Spooner said, "and that validates that the entire process going back to '07, that all of us involved including the district personnel, contracted personnel and our employees, we did our jobs and we did them well."
Updated: October 24, 2017 07:48 PM
Created: October 24, 2017 06:27 PM
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