Since 2000, when UT-Battelle took over management of ORNL, six new buildings totaling 750,000 square feet of office and state-of-the-art laboratory space have become home to more than 1,000 of the lab's 4,100 employees. Energy consumption at the new facilities is less than half that of the buildings these replaced, but that is just the beginning of the story.
"All six of the new buildings have met ORNL sustainability commitments by achieving LEED (Leadership in Energy and Environmental Design) certification," said Lanny Bates, director of the lab's Facilities Development Division. "Most impressively, the Joint Institute for Computing Science has achieved LEED silver certification and the Tennessee Office Building has achieved gold certification."
LEED criteria were developed by the U.S. Green Buildings Council (www.usgbc.org), a building industry coalition that promotes environmentally responsible technologies. LEED promotes a whole-building approach to sustainability by recognizing performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality.
To date, the east portion of ORNL is the only fully LEED certified campus in Tennessee and the only one in the Department of Energy complexes nationwide. The facilities save more than 5 million gallons of water annually through the installation of low-flow plumbing fixtures. In addition, three-fourths of all occupied spaces receive natural lighting, and hybrid solar lighting units are being installed at the Tennessee Office Building. This system, which collects sunlight with 48-inch diameter dishes and channels the sunshine into buildings through optical fibers connected to hybrid light fixtures, can save up to $1 million per 100,000 square feet over 10 years.
Overall, the new buildings represent a huge commitment -- $150 million - that is part of a six-year modernization program designed to replace and consolidate research and office space. In the first two months of operation, three of the six new buildings saved more than 5.5 billion British Thermal Units (Btu). One Btu is the amount of energy required to raise one pound of water one degree Fahrenheit.
Looking at the numbers, the six new buildings (595,000 square feet) -- excluding the computer center - consume 146,800 Btus per gross square feet per year while Building 4500 North (341,000 square feet) uses 323,000 Btu/gsf. Building 4500N is one of the largest office/lab complexes at ORNL and houses 500 researchers and other personnel.
The new buildings feature materials selected for their recycled content, low emissions of volatile organic compounds, insulation value and durability, cost and aesthetic value. Carbon dioxide monitors and high-efficiency air filters ensure good indoor air quality. Other features include efficient lights, occupancy sensors, Energy Star office equipment and variable frequency fan drives that keep energy use low.
For comparison purposes, the average utility cost per gross square feet for the new buildings is $1.98 while the cost per square foot in Building 4500N is $3.89 per square foot. Part of the reason is the use of walls with a whole-wall R-values of 15 or greater and roofs that are R-25 or greater. Other energy-saving features include high-tech glazing, sunscreens, roof and balcony overhangs and low-infiltration window frames.
While these buildings cost more to build, the additional cost is minimal, adding between 1 percent and 2 percent to the cost, according to Bates, who noted that, "in the end you have a building that will help conserve resources, improve air and water quality, and make a statement."
Even landscaping was done with consideration to the environment, Bates said, as native plants that are drought-tolerant were selected. Trees and shrubs were chosen for their shading characteristics and concrete with high reflective power was used to minimize the sun's heating effects on pavement. A storm drainage system allows rainwater to filter through pervious pavement and rock beds and collect in a holding area under the surface as long as possible to provide water to grass and foliage.
To save energy in the central and west ends of the laboratory, facilities management staff have reduced excessive air flow, which makes it less expensive to heat and cool the buildings because this reduces the demand for chilled water and steam. Because one of the buildings, 4500 South, consumes 10 percent of the chilled water and steam, any reduction is significant, Bates said. Other energy-saving strategies include condensate returns and variable frequency drives.
ORNL is managed by UT-Battelle for the Department of Energy.