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Geothermal System Qualifies University For LEED Certification

The recent growth of private Davenport University called for new facilities far beyond what the school’s historic old campus in downtown Grand Rapids, Michigan could provide. But university officials wanted far more than size to position Davenport to meet its growth objectives, and to transform from an adult-commuter school to one that could attract traditional 18-to-22-year-old college students.

For its new four-story, 134,000 square-foot home in nearby Gaines Township, opened in 2003, the key to the effort lies within 120 holes in the ground - the basis for the geothermal heating and cooling system that regulates temperatures for the 134,000-square-foot academic building, as well as the two adjacent residence halls.

The general contractor on the project was Grand Rapids-based Rockford Construction, working in conjunction with primary architect GunnLevine of Detroit and mechanical engineers GMB Architects of Holland.
The geothermal system is the primary piece of an effort to qualify the building for certification under the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) system - a major objective of the Davenport University Board of Trustees. School officials also believe the system is performing better than a traditional system - using less energy and providing more comfort - while costing less.

The campus is home to nearly 2,000 students, and the new facility represents Davenport’s first attempt to provide a more traditional college experience with residence halls, food service and recreation facilities. A new 84,000-square-foot student center, set to open in 2008, is the next phase of that effort.

“ Campus leadership decided this was going to be LEED-certified,” said Jim Bescey, director of facilities for Davenport. “The design of the building got steered toward this heat pump system, which is creative and provided a number of LEED points from an energy modeling standpoint. The long-term benefits, beyond LEED, are the energy efficiencies and operating efficiencies you enjoy.”

What Bescey describes as a geothermal loop system draws 55-degree ground water, runs it through a chiller in the facility basement to convert it for both heating and cooling use, then pumps it up to a fourth-floor energy recovery unit (ERU). From there, the centralized system distributes hot and cold air through individual units in classrooms and offices.

But there is only one pump - a detail that mechanical engineer Steve Hamstra of GMB considers crucial.

“ This was the largest geothermal energy plant we had done,” Hamstra said. “We had done a smaller one in an elementary school before this project, but this is the latest geothermal application, and this overcomes a lot of opposition in the marketplace to geothermal, because building engineers don’t want to deal with 150 small heat pumps and the maintenance associated with them. I’m a central plant guy. I prefer to centralize my maintenance as well. This has opened a lot of doors to us for the efficiency we can get with a geothermal system, while reducing our maintenance costs.”

The chiller also pumps water from the basement of the main building to the two residence halls approximately 75 yards away, and heats and cools the residence halls as part of the same loop.

The geothermal wells were drilled in and around the facility’s north parking lot. The only visible evidence of their existence is a manhole that would hardly strike an observer as noteworthy.

Hamstra said the system design was based on the latest German advances in geothermal technology.

“ We wanted to bring some induction technology into the U.S., and this is the first time an induction displacement ventilation system has been applied to this kind of system in the U.S.,” Hamstra said. “That technology came out of Germany, and we liked the opportunity to use warm and chilled water systems at 55 degrees instead of your traditional 45 degrees chilled water.”

Hamstra said the induction displacement ventilation units eliminate the need for a compressor and permit the system to rely solely on the geothermal pump.

Bescey described the approach as very theoretical, but pronounced the university’s leadership happy with the results.

“ You’re getting into the aquastructure of this area, and the theoretical idea of geothermal system is that, down below the Earth, there is this heat sink of 55-degree constant water temperature,” Bescey said. “In West Michigan, this is a one-of-a-kind system.”

The energy recovery fans operating at the top of the loop also make it possible for every room in the building to have fresh air at all times.

“ The building is ventilated at a higher rate than the typical academic building,” Hamstra said. “We have fresh air in pretty much every classroom, because 100 percent of the air that goes into the room goes out of the room and is exhausted. We don’t recirculate any air from one classroom to another classroom - and we use the energy recovery unit to do that.”

Hamstra estimates that the geothermal system is using 30 percent to 40 percent less energy than would a traditional system - while outperforming it in terms of providing comfort.

“ We designed it to control the building to a low level of humidity in the summertime,” Hamstra said. “We hold this building down around 40 percent relative humidity, and between 72 and 75 degrees - which is much more comfortable. It’s nice and dry and refreshing when they come in from the humid weather, so from that perspective, we actually exceed normal design conditions inside.”

While the university has yet to precisely quantify its cost savings, Bescey believes recent increases in the price of natural gas - the basis for the university’s old system - provide ample evidence that the investment is providing returns.

“ Natural gas in the last couple of years has really skyrocketed pricewise, post-Hurricane Katrina,” Bescey said. “This application, because it’s all electricity - making chilled water and using electricity 12 months out of the year, and very little natural gas - with the whole dynamics of the natural gas market, this is really going to shine from a cost-saving standpoint. Five-to-10 years ago, when natural gas was cheap, these systems were hard to justify.”

Rockford Construction had never before built a facility using a geothermal HVAC system, according to project superintendent Jeff Brakefield. But aside from leaving large holes in the bottom- and top-floor walls to account for the installation of the chiller and ERU, he said the project was smooth so long as he relied on GMB and GunnLevine for guidance on the engineering issues.

“ The only real difference was the presence of the geothermal well field,” Brakefield said. “Once you get the building constructed, you have a similar pipe configuration in the building.”

But as the project superintendent, Brakefield said he was challenged to coordinate a large subcontractor team and meet a schedule twice as fast as would be typical for such a project.

“ We were going through the heart of the winter,” Brakefield said. “A lot of this stuff had long lead times, so coordinating the schedule was the biggest challenge, and we were constantly worrying about the weather.”

Complimenting the geothermal heating and cooling system are a Steelcase Polyvision Audio-Visual system, along with a web-based classroom system called Thunder that allows classroom notes to be stored in a Windows-based format that can be downloaded off the web.

The entire campus is wireless-networked with a series of routers, and Bescey said the residence halls have also been wired for far more technology than they are currently using - an attempt to prepare Davenport for future technology trends in higher education.

As much as Davenport touts the geothermal heating and cooling system for its main building and residence halls, it will use a more traditional system for its soon-to-begin-construction, 84,000-square-foot student center.

Bescey said the university found it could achieve LEED certification for the student center without the geothermal system, and found that the needs of the facility were such that they argued for a more traditional approach.
“ There is an upfront cost with the geothermal and the drilling of the wells,” Bescey said. “We couldn’t tap into the existing geothermal, so this one will be fairly conventional.”

The student center, which will sit on 10 acres west of the other buildings, will achieve LEED certification with an efficient HVAC system and the types of wall insulation and glass used, as well as other items like low water-flow for landscaping.

Rockford Construction will also be the general contractor on the student center project. Brakefield, who has managed the Davenport project since its inception, says he will have the unusual experience of remaining on the job to the point where, by the time the student center is finished, he will have been working on-site at Davenport for seven years.

But the main facility remains the primary source of pride for Davenport, which believes it has achieved an ideal combination of energy efficiency, environmental sensitivity, efficient design and long-term viability.

“ It’s apparent when you walk in and see the overall quality and finish of this building, the granite tile, the glass system with an integrated sun shade - we’re at the high end of finishes by anybody’s standards,” Bescey said.

The finishes are very high-end, and the door hardware and frames have 50-year lives. We have material here that will last 25, 30, 40 years, so we’ve really gone the extra distance in creating an environment we feel is exceptional in terms of how it’s laid out and how it’s finished.”

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