HARRISBURG, PA -- As the sun beats down on one of the biggest buildings in the country, solar thermal collectors go to work providing enough heat for a 1.7 million square foot warehouse.
Spread across more than 40 acres, the Defense Logistics Agency's (DLA) Eastern Distribution Center in New Cumberland, Pa., provides critical supplies for the military stationed overseas. DLA needed an alternative, cost-saving way to provide heat for this massive warehouse.
In the summer of 2011, Headquarters U.S. Army Corps of Engineers approached the U.S. Army Engineering and Support Center, Huntsville about an Energy Conservation Investment Program energy reducing project. Huntsville Center teamed with the Corps' Baltimore District to build the largest induction solar wall in the country.
"The project installed Solar Thermal Collectors on portions of the East and South walls for a total of 55,263 square feet of solar wall," said Dennis Lacy, Huntsville Center project manager. "This system provides preheated outside air to air handling units and the large fans located inside the warehouse."
Lacy compared the solar wall to layered clothing on the skin of the building. "The air gets in, and the sun warms it, providing heated air for the building's use," he said.
This two-phased solar wall contains a bottom portion of normal solar wall with a top portion that seals the air intakes.
"The bottom portion lets the air in," Lacy said. "The heated air rises and goes up to the top half, which is sealed off with a membrane to cover the perforations. The membrane considerably assists the outside air to only entering the system at the bottom section of the solar wall, providing additional insulation to the top half of the solar wall."
When the wall reaches 180 degrees, the dampers at the top portion open up to allow the heat to enter the warehouse, where large fans are strategically placed to circulate the heat evenly. In the summer, DLA will close the dampers to prevent unnecessary heat in the warehouse.
"It could be 27 degrees outside, but the sun beating on the wall will still heat it up to 180 degrees," said Curt Ellsworth, Baltimore District construction representative.
It is estimated that this solar wall will save DLA $350,000 in annual energy costs.
Remi Bollana, Baltimore District's Harrisburg Area Office resident engineer, said he looks forward to seeing the results from the measurement and verification test.
"The test will show us how much fuel DLA can expect to save each year, and those funds can be re-allocated toward other programs," Bollana said.
This $3.4 million project took less than a year to build.
The U.S. Army Corps of Engineers strives to protect, sustain, and improve the natural and man-made environment of our nation, and is committed to compliance with applicable environmental and energy statutes, regulations, and Executive Orders. Sustainability is not only part of the Corps' decision processes, but is also part of its culture.