By Mr. C Gardner (USACE)July 1, 2010
FORT DRUM, N.Y. -- With construction booming and the Army looking for more ways to "green" its construction practices and buildings, the Fort Drum Program Office of the Army Corps of Engineers New York District, decided to look into alternative sustainable energy sources for new construction. One of the sustainable energy sources was geothermal systems for heating and cooling.
The corps first started using geothermal systems at Fort Drum in 2004, for the construction of the Wheeler-Sack Air Field Complex. This system provided a renewable source of energy for heating and cooling. The temperature below the earth's surface remains nearly constant between 50 and 60 degrees Fahrenheit. The geothermal system consists of a network of pipes buried in the ground filled with liquid which acts as a heat exchanger to transfer energy to and from the building. The geothermal heat pump system provides temperature control inside buildings without the burning of fossil fuels like traditional systems.
"By using these systems we exceed our military energy requirements and reduced utility costs for Fort Drum," said Edward Sim, New York District's Program Manager at Fort Drum.
As far as the occupants experience in these facilities, the actual heating and cooling of rooms works similarly to traditional systems. Occupants can adjust the temperature on a room-by-room basis and the installation can adjust the temperature from a central location.
After success with the geothermal systems in barracks projects from 2004 through 2008, the Fort Drum Program Office is now providing geothermal as a primary option for heating and cooling needs in all new construction where it's feasible (geothermal doesn't lend itself to large open-area buildings, like hangars and vehicle maintenance facilities, where instead the corps uses a green feature called 'solar walls').
Projects that lend themselves to geothermal heating and cooling range from barracks facilities to administrative buildings.
"We heard concerns during the design phase in 2003 that geothermal systems would not work for our applications," said Phil Favret, project manager at the Fort Drum Program Office. "But the Wheeler-Sack barracks is proof that the systems do work here at Fort Drum."
A new Child Development Center (CDC), which is now under construction incorporates a geothermal heating and cooling system. The facility is designed to be Fort Drum's first LEED Gold building. The $6 million building is essentially the Army's equivalent of a daycare center. The facility will be approximately 17,000 square feet, and contractors have drilled 16 wells to handle the facility's heating and cooling needs. The wells are approximately 425 feet deep and took about a week to drill. The depths of the geothermal wells will vary throughout the installation depending on the geology/thermal conductivity of the area.
Using geothermal energy reduces energy costs by reducing the amount of fossil fuels burned which can be intense during Fort Drum's extreme winters - where temperatures can reach well below zero and have been known to reach the negative thirties. The geothermal performs very well, even in the cold, said Favret, but he did note that in the most extreme temperatures the system can sometimes need a boost from traditional heating sources.
Despite geothermal costing of approximately 30 percent more during the construction phase than traditional heating and cooling systems, Sim said that "payback," the amount of time it takes for a facility to recoup that initial cost with money saved in utilities, is generally three to seven years.
The payback time depends on the building size and the fluctuating cost of fossil fuels, which as of recent years has actually shortened the estimated payback time. He said the Program Office is looking into monitoring systems to determine the specific return on investment of geothermal at Fort Drum.
During the initial design of the Wheeler-Sack Air Field Complex in 2002, engineers from the Fort Drum Program Office met with the local Indian River School District which incorporated a geothermal system into one of their large building additions. They toured the facility and talked to the users as well as the design firm to get a better idea on the system operation and performance capabilities.
After learning more about the concept, visiting other facilities that utilized geothermal and getting a better understanding of the specifics of geothermal design, the program office was ready to incorporate it into the designs and contract language of the barracks in the Wheeler-Sack Army Airfield Complex being solicited. The barracks were two of 17 buildings in a $100 million complex that was completed in 2006.
Favret said they were pleased with the end result of the project, and a bit surprised of how well the geothermal systems worked in the minus 20 degree temperatures. "We conducted a survey of the residents in the barracks over at Wheeler-Sack Barracks and we received positive responses from all surveyed," Favret said.
Since then, geothermal has been incorporated where feasible during the construction of facilities since 2004. As of today, geothermal has been incorporated into 19 buildings currently completed, under construction or under design at Fort Drum.
This includes the aforementioned Child Development Center, 11 barracks buildings, a brigade and a battalion headquarters building and the addition to the Guthrie Medical facility. It was also used in the recently completed Warrior in Transition Complex constructed for injured Soldiers and will be included in the next two facilities to be added to this complex.