A Lesson in Saving Energy: Geothermal System at Inderkum High School One of the Largest in Nation

The heating and cooling system at the recently completed campus in northwest Sacramento is expected to last 50 years compared to the eight- to 15-year life expectancy of a traditional HVAC system. The project manager for the contractor that installed the geothermal system said it cost more to install than a conventional system, but is less expensive to operate and maintain.

By Thomas York

	PHOTO COURTESY OF NACHT & LEWIS ARCHITECTS

Designers and contractors in California can learn a thing or two from Inderkum High School, a 235,000-sq.-ft. facility opened two weeks ago by the Natomas Unified School District in northwest Sacramento.

The Sacramento office of Turner Construction Co. provided construction management services for the two-year, $52.5 million project that included such forward-thinking innovations as:

• A geothermal well field placed under the campus parking lot that provides space heating and cooling to nearby classrooms. It pumps piped water into 500 275-ft.-deep wells, where the temperature is a constant 65 degrees. The water is warmed in the winter and chilled in the summer before it is circulated throughout the school.
• A 450-kilowatt photovoltaic system-that provides up to one-third of the school's daily power requirements.
• Solar "tubes," or skylights, that stream sunlight into interior rooms and clerestory windows and glass walls that open interior spaces and classrooms to natural daylight.

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"With the exception of a control booth in the theater, all the space on the second floor is flooded with natural light," said the project's director of design, Andy McPherson of Sacramento-based Nacht & Lewis Architects.

The Natomas Unified School District received a $2 million rebate check from the Sacramento Municipal Utility District for the new energy-saving photovoltaic system that will supply electricity to the power district's grid during the school's summer recess. School officials believe the system will provide up to 33 percent of the school's electric power needs in the summer.

Brian Haggart, project manager for Oklahoma City-based Trison Construction Inc., one of the project's contractors, said the geothermal heating and cooling system installed by his company is the largest geothermal project in California and "certainly is one of the largest in the country."

Haggart said that the system cost roughly one-and-a-quarter to one-and-a-half times as much money to install as a conventional system, but will be much cheaper to operate and maintain over time. The system should last about 50 years compared to the eight- to 15-year life expectancy of a traditional HVAC system.

"All the equipment sits underground, so it can't be damaged by vandalism or weather," Haggart said. "There are no cooling towers or other equipment sitting on the roof."

	The basketball court's wooden floor is one shining component of Inderkum High School's new $52.5 million campus (photo courtesy of Nacht & Lewis Architects).

The high school's two-story design is more commonly seen in the East and Midwest, where long stretches of cold weather require more energy-saving systems than in California.

To further reduce energy needs, the campus' buildings cover just 37 acres instead of 60-the standard for a traditional high school campus in California, McPherson said.

The 2,000-student Inderkum High was named after a dairy farming family that previously owned the property. The school centers on four, two-story classroom modules fronting an enclosed atrium, a spot where students can socialize between classes.

The new Inderkum campus is part of a greater effort to centralize public services in the fast-growing Natomas area. The city of Sacramento is building a library and 200-acre regional park next to the high school, while the Los Rios Community College District broke ground last month for a new campus on adjacent property. Completion is set for August 2005.

City officials have applied for bond money to build the new library. In addition, Sacramento Light Rail is planning to build an extension and transit station that will connect the campus with downtown Sacramento.

Using funds from state bonds, private developer Concord Eastridge of Phoenix financed construction of the campus under a long-term contract with Natomas Unified, which will lease the school from Concord Eastridge for 40 years, at which time Concord Eastridge will return ownership to the district.

Developer Edward Eastridge said the approach enabled the district to speed design and construction of the campus, which will relieve chronic overcrowding at sister campus Natomas High School.

"The project is under budget and ahead of schedule," said Eastridge. "That's unique in the public school world."

Dave Tooker, superintendent for Natomas Unified, is widely credited for bringing together the various agencies to create a town center in Natomas. He said the finished campus will revolutionize high school construction in California.

"Usually, we take a very conservative approach to public dollars," Tooker said. "But in this case, we took a very different approach, with what we believe are excellent results. It looks more like the inside of a mall than the inside of a sterile educational facility. When parents see it, they say, 'Wow!'"