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Geothermal Wells to Help Cool NASA Facility
04.22.13
 
NASA's Langley Research Center in Hampton, Va., is steadily going greener and greener -- but not without making a few messes.

Geothermal Well Drilling

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A crew drills a well at NASA Langley's geothermal exchange field. The wells are part of a hybrid system that will help cool the Integrated Engineering Services Building. In all, the exchange field features 140 wells drilled to a depth of nearly 400 feet. Photo courtesy of Gary Stergin


Gary Stergin

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Gary Stergin, project manager for NASA Langley's Integrated Engineering Services Building, uses a hand-drawn schematic to explain how the geothermal exchange field will help cool the building. Credit: NASA/Dave Bowman

It's part of the center's 20-year revitalization plan.

One of the messes comes in the form of a mucky mud pit. There's really no other description for the wide, fenced-in parcel of land next to one of the wind tunnel buildings at the center.

Formerly a parking lot, the 2.3-acre (9,308 square meters) plot began undergoing a transformation late in November of last year. That's when crews came in to tear up the pavement and begin work on a geothermal exchange field.

That field is part of a system that will help cool the Integrated Engineering Services Building (IESB), which is under construction and slated to open in June of 2014.

In all, the exchange field features 140 wells, dug to a depth of almost 400 feet (122 meters) each. Crews did most of the drilling during the soggy, chilly months between December and March.

According to Gary Stergin, NASA Langley's project manager for the IESB, in a good week -- one not hampered by weather delays -- crews were able to drill about 15 wells. The ground temperature at the bottom of those wells hovers at around 62 degrees (about 17 degrees Celsius).

But this system, which Stergin refers to as a "hybrid," relies on more than just the cool ground temperatures to work.

"What makes it a hybrid," Stergin said, pointing at a hand-drawn schematic on a dry erase board in his office, "is the addition of this fluid cooler here, which is mostly, for lack of a better term, like a cooling tower. You see them all over the center here. And that's going to be installed on the roof of the new building."

In the simplest terms, the system will work something like this:

A compressor at the building site will pump hot Freon gas through cooling coil heat exchangers that are fed by both the geothermal well field and the fluid cooler. The water in those coils will cool the Freon down from 140 degrees to about 90 degrees (60 to 32 degrees Celsius). The Freon will then travel to an expansion valve where it will cool down even more, to about 45 degrees (7 degrees Celsius). From there, it will circulate through cooling coils that have air blowing across them, providing cold air to the building.

Because, among other functions, the IESB will house NASA's Langley's cafeteria and all its associated industrial-size kitchen appliances, a lot of audio-visual equipment and an auditorium that will frequently play host to large groups of people, Stergin expects the heat load to be high.

"You're always going to be trying to shed heat from this building," he said.

So having an efficient cooling system is important. And Stergin believes the hybrid geothermal/fluid cooler system will work very efficiently -- so much so that he's anticipating it will help the IESB earn a gold rating from the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) program.

In the meantime, work continues and the mucky mud pit is beginning to look a little less, well, mucky. All the wells have been drilled and the 2.3-acre (9,308 square meter) site has mostly been smoothed over.

By: Joe Atkinson

The Researcher News
NASA Langley Research Center
Editor & Curator: Denise Lineberry
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