New designs and materials are reducing commercial energy costs.
Ability and reputation. Andre Desjarlais believes these two simple words describe the primary attraction for industrial users to Oak Ridge National Laboratory's Building Technologies Research and Integration Center (BTRIC). "We have experimental capabilities that are not available anywhere else in the world," he says, "but it is the quality of our staff and their reputation for impartiality in the building materials industry that leads researchers to our door." Manufacturers know that if they need to send data to a building code agency or to a potential customer, a report with "ORNL" on the letterhead strengthens the credibility of the information.
Desjarlais recalls that, when established in 1987, the Building's Technology Center was the Department of Energy's first designated user facility at ORNL. From the beginning, DOE invested heavily in equipment for conducting state-of-the-art energy-efficiency research. With frequent upgrades, the unique equipment has remained state-of-the-art for more than two decades. The center, for example, still gathers data using the Large-Scale Climate Simulator (LSCS)—a huge apparatus that can enclose building components, such as roof or wall sections, within a highly customizable micro-climate. While most large-scale test facilities can control temperature, the LSCS offers researchers the added benefit of controlling relative humidity, sunlight, rainfall and other variables. This broader collection of data provides the user with a much more realistic testing environment and ensures a higher reliability of test results. Because of these unique capabilities, Desjarlais says ORNL is often called upon to simulate the climate of a particular city or region, noting that, "One day we'll be simulating Miami and the next day Anchorage."
Because roofs and attics represent some 25 percent of commercial heating and cooling costs, industrial users are particularly enthusiastic about using ORNL's simulator to study the efficiency of roofing systems. The LSCS has a unique advantage in these studies because, while other facilities are limited to testing flat pieces of roofs, it can accommodate three-dimensional roof and attic assemblies.
The roofing innovation that has generated the most interest in recent years is "cool roofing," a technique that involves changing the color of the roof to reflect heat away from the building. This seemingly innocuous alteration can significantly reduce air-conditioning costs for a building, particularly in America's sunbelt regions. The center at first worked with manufacturers to develop white or very light-colored roofing for flat-roofed industrial buildings because white roofing reflects the greatest amount of sunlight. However, after gathering data on sloped roofing for residential applications, scientists determined that most homeowners do not want white shingles on their roofs. "We worked with a number of paint and pigment manufacturers to come up with more traditional colors and finishes that would still reflect much of the sunlight away," Desjarlais said. This "compromise" approach kept homeowners happy and still decreased cooling costs.
Although the center was created as a test bed for increasing the energy efficiency of roofs and walls, over the years its capabilities have expanded into testing and evaluating internal building components, such as appliances and heating and cooling equipment. While perhaps less visually impressive than the LSCS, the additional test facilities provide the center with research capabilities to which 99 percent of American industry does not have access. However, despite the center's wide-ranging capabilities, the BTRIC does not compete with the private sector. "If a user wants to perform a fairly simple test that can be conducted at a commercial lab," Desjarlais said, "we direct them to those labs. We work only with clients who have exhausted commercial testing options."
Despite these restrictions, over the past decade the number of users wanting access to the center's research capabilities has increased, while limited capacity has kept the number of users relatively stable. Recent funding investments by the Department of Energy, including $20.2 million to construct an Integrated Net-Zero Energy Buildings Research Laboratory, suggest that BTRIC will be able to accommodate a larger number of users in coming years.
One of the center's current users is the Metal Building Manufacturers Association (MBMA), an influential industry group that promotes the design and construction of metal buildings. Oak Ridge researchers are working with the association on a series of tests involving next-generation metal building roofing systems that have been redesigned to increase energy efficiency. During each round of testing, MBMA engineers build a section of roofing. BTRIC scientists then add instrumentation, run climate simulation experiments and share the results with MBMA. Equipped with these data, MBMA engineers redesign the prototype, and the cycle is repeated until the optimum design emerges.
MBMA engineer Dan Walker noted that the aim of these studies is to create metal building roofs that meet or exceed proposed code requirements. "Our research is designed not only to improve the performance of existing roof construction methods," he said, "but also to develop new construction methods that will result in more energy-efficient metal buildings. Our goal is to develop roofing systems that people will use, that are easy to install and that are both cost effective and energy efficient."
Walker explained that the process of developing more efficient roofing systems at the BTRIC involves a lot of give and take among MBMA and BTRIC staff. "We are providing technical expertise about our product, and Oak Ridge scientists are providing technical know-how about heat transfer fundamentals," he said. "ORNL is helping us identify areas where we can make the most effective changes to increase the energy efficiency as much as possible." The studies could have far-reaching implications if the results help the rapidly expanding metal building industry make decisions about how their designs will evolve and how these changes will affect energy efficiency. In the longer term, Walker said that MBMA is hoping to secure funding to gather whole building energy measurements on a commercial metal building to determine what changes can be made to increase the efficiency of existing buildings, as well as that of new designs.
The center's work with MBMA is emblematic of the kind of relationship BTRIC seeks to cultivate with industrial users. The research also highlights the center's primary mission: removing barriers that discourage industry from using more energy-efficient construction practices. The center does this by interacting with companies and industry groups to explore innovative ideas, accelerating promising technologies and providing sophisticated testing that is impractical to conduct in the private sector.
"We spend a lot of time interacting with the building industry," Desjarlais says. "ORNL does not have a monopoly on good ideas, so we always want to know what people in industry are working on, what interests them and what role we can play. If we discover that industry shares an interest with the Department of Energy, we put the two pieces together and try to create collaborative research projects to accelerate progress in the area of interest. When we do this, energy use goes down, costs go down and everyone gains from the interaction."
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