Warm Feet, Cool Heads

Maine may not be a hotbed of geothermal activity, but two midcoast school districts are nonetheless fighting back against high oil prices by drilling holes in the ground. It’s all part of an effort on the part of school administrators, architects, faculty, and even students to create “smart buildings,” which use energy more efficiently.

At Camden Hills Regional High School (CHRHS), an entire academic wing is heated in winter and cooled in spring and fall by means of 21st-century heat-exchange technology. And a new addition to nearby Rockport Elementary School West, scheduled to break ground this October, will use a similar ground-source system to heat and cool the whole building.

Keith Rose, facilities director for both school districts, explains that the process works much like a kitchen refrigerator. “Your refrigerator’s heat pump extracts the BTUs from whatever’s inside, and that heat ends up in the coils. We’re using the exact same process with three drilled wells.”

Water more than 300 feet below ground remains at a constant year-round temperature of around 50°F. A heat-exchange system like the one at CHRHS works by extracting heat from the water, which is then returned to the ground at a lower temperature. In warmer months, the process is reversed, heating the water and cooling the school. Although the process consumes electricity, the cost is more than offset by the savings in fuel oil. “All told, it’s saving us anywhere from 10 to 25% as compared to the cost of running an oil burner,” Rose says.

But that’s not the school’s only cost-saving innovation. According to Erik Greven, a principal at Harriman Associates, the Auburn-based architectural firm that designed the school, CHRHS was a precursor to the current building trend that is producing school buildings nearly as intelligent as the people who occupy them.

“You have to remember that the school was designed nearly 10 years ago,” Greven says. “Nonetheless, it was on the cutting edge of attempts to save energy in schools and other public buildings. It’s a very smart building.”
Rick Miles, senior mechanical engineering designer at Harriman, offers the following example: “In a large area, such as the auditorium, occupancy varies widely. You could have 16 people in there for a gym class, or 600 for an assembly. And, obviously, all those people are breathing and exhaling. Our system can detect how much carbon dioxide is being exhaled. It can detect minuscule drops in the oxygen level in the room, and drive the ventilation system accordingly.”

Similar systems, known as “optimization controls,” regulate temperatures and energy use in other parts of the building. Patterns of seasonal and day-to-day use determine energy outlays, without humans having to be there to turn down a dial or throw a switch.

Other design factors promote better learning environments. The classrooms at CHRHS all have heated floors. “We used the whole floor as a baseboard, running heating pipes throughout the concrete in the floor,” Greven says. “Studies have shown that students learn better when their feet are warm and their heads are cool.”

The layout of the 172,000-square-foot building clusters departments, with math and science at the far end of the geothermally heated wing, humanities in another section of the same wing, and industrial technology and fine arts in a separate area on the far side of the cafeteria, which is more like a food court than an old-style school lunchroom. The library and the auditorium are centrally located, off the main lobby. Today’s students are benefiting from a design plan that anticipated the flow of a school day, from classes to lunch breaks to athletics and extracurricular activities.

Harriman has designed several new schools in southern Maine and New Hampshire, though Camden Hills Regional High School is their most recent project in the Bangor metro area. All are certified by the U.S. Green Building Council as conforming to Leadership in Energy and Environmental Design (LEED) standards, a nationally recognized benchmark for the design, construction, and operation of high-performance, energy-efficient buildings. In November 2003, Gov. John Baldacci issued an executive order mandating that all new state buildings be LEED certified. Although the order is not binding on schools, Greven says, “It’s the industry standard that we follow.”

Camden-Rockport students are also getting into the energy-saving act. For the past year, a group of students has been collecting wind data from atop a 140-foot meteorological tower at the school. Rose says the data will be used to determine the feasibility of erecting a wind generator to supply part of the school’s electricity needs.

The Rockport Elementary School West addition, which will quadruple the size of the school from 20,000 to 80,000 square feet, is being designed by PDT Architects of Portland. Rose said the district is considering a geothermal system modeled after one in use at Gorham Middle School in southern Maine, in which the heat from the water in the ground is transferred to circulating pipes filled with an antifreeze solution. Such a “closed” system will be able to provide heat for the whole building, Rose says. It differs from the “open loop” system at CHRHS, in that the water is not pumped out of and returned to the wells.

The project will go out to bid this summer, and the work is expected to be finished in time for the beginning of the school year in September 2009.

“The intent is to go all geothermal for the building’s heating,” Rose says. It’s just one more example of today’s technology helping out the innovators of tomorrow.