This article appeared in Western Roofing magazine January/February 2004.
Saving Energy
Energy Star Roofing Makes the Steep Slope Switch
by Heidi Ellsworth, HJE Marketing
Black outs in New York, rolling brown outs in California, energy, and more importantly, energy saving procednures are making headlines. Energy Star® rated products are a common theme in commercial roofing systems, but what about steep slope roofing? Homeowners are looking for ways to save energy and in turn, money. Roofing contractors are looking for ways to supply the demand. Maruhachi Ceramics of America, Inc., (MCA) has made huge strides forward to provide homeowners and contractors with roofing tiles that are Energy Star rated. MCA is a cool roof clay tile manufacturer and a leader in providing the solution for steep slope energy savings.
The past five years, MCA has worked to provide not only Energy Star rated roofing tiles, but also stronger Energy Star solutions for steep slope roofing. MCA is one of several industrial partners participating in a California Energy Commission Public Interest Energy Research (PIER) project to make cool-colored roofing products a market reality within the next four years. The PIER project is a collaborative effort among the tile, metal, cedar shake and asphalt shingle roofing industries, the Lawrence Berkeley National Laboratory (LBNL) and the Oak Ridge National Laboratory (ORNL). Dr. Hashem Akbari, a researcher for the Heat Island Project at LBNL and Dr. William Miller of ORNL are working with MCA to further improve and document benefits of cool colored clay tile. “The Roof Tile Institute is interested in better understanding the venting of air between the roof deck and clay and concrete tiles,” said Miller. “The convection heat transfer in this space may be mixed and the heat transfer issue poses significant reductions in heat transfer penetrating the roof.”
“We are in the process of soliciting participation from manufacturers like MCA to develop cool roofing products with higher reflectivity in an ever widening range of colors, and are investigating new cool colors that will further increase the reflectance of MCA’s palette of clay tiles,” stated Akbari. “MCA has some of the highest reflectance available with their roofing tiles.” MCA and other Roof Tile Institute participants have Miller of ORNL conducting field experiments to document the thermal and energy benefits of clay and concrete tile. ORNL has MCA’s gold buff tile, having a reflectance of 51.5%, under field study.
“Energy Star roofing materials must have a minimum of 25% reflectivity that will not decrease below 15% after three years,” stated Akbari. “For Title 24 the California Cool Roof standard is 40%. MCA satisfies those requirements easily, said Akbari.
MCA is producing a wide range of colors and blends that carry the Energy Star label. “It is due to MCA’s ceramic technology,” stated Yoshihiro Suzuki, general manger and director for MCA. “Our tile helps lower the roof surface temperature and decrease the amount of heat transferred into the building’s interior.”
According to www.title24express.com, California continues to set the standard for energy efficiency with Title 24. The energy efficiency standards for residential and non-residential buildings were established in 1978 in response to a legislative mandate to reduce California’s energy consumption. The standards are updated periodically to allow consideration and possible incorporation of new energy efficiency technologies and methods. Commission standards went into effect on June 1, 2001. The standards, along with standards for energy efficient appliances, have saved more than $20 billion in electricity and natural gas costs. It is estimated the standards will save $57 billion by 2011.
Researchers at LBNL and the Florida Solar Energy Center (FSEC) have measured cooling energy savings of up to 60% for individual homes where white roof coatings were applied to dark roof systems. Much of the extra heat from these roof systems make its way into an attic and then the house, though the heat transfer is slowed by attic insulation. A cool roof system – one that reflects solar radiation and emits thermal radiation well – keeps a building cooler and helps reduce air-conditioning costs.
“MCA’s Energy Star colors are part of our standard product line. They are the colors and blends architects, homeowners, and developers have been specifying for years,” Suzuki said. “There is no additional cost for selecting a color from MCA’s Energy Star list, and all are covered by the same warranty as any other MCA product. We are continuing to conduct solar reflective measurement tests, and are adding more colors to our growing list of Energy Star compliant products.”
Roofing contractors are experiencing the benefits of providing Energy Star labeled roofing systems. In California, there have been rebates offered that have provided tremendous incentives to homeowners. The fact that the cool roof trend is primarily in California is not a situation that will last. In a recent article out of the Arizona Republic, columnist Kathleen Ingley urged Arizona residents to push for cool roofing. “Cool roofs have been astonishingly slow to catch on,” wrote Ingley. “We need governments to set an example in public buildings, a public push to spread the word and incentives to get the ball rolling.”
Ingley also writes, “The Sacramento Municipal Utility District has been a leader in encouraging cool roofs, part of its strategy to meet a California mandate to control demand. It originally offered rebates of 20 cents a square-foot, but has gone to ten cents with plans to phase out the money as cool roofs become an industry standard.”
MCA was part of the original push for cool roof rebates. With properties like the Hyatt Regency and Palm Desert Housing Authority, reroofing with MCA Energy Star tiles set a precedent while also receiving hefty refunds for using the Energy Star tiles.
Greg Villegas, project architect for Wimberly, Allison, Tong & Goo Architects, Newport Beach, Calif., who worked on the Hyatt Regency in Huntington Beach, Calif., liked the combination of energy savings and aesthetics. “We used the Energy Star Old Mission Blend® on the Hyatt,” noted Villegas. Letner Roofing in Orange, Calif., installed the roof and PCL Builders were the builders for this job, which utilized about 3,000 squares of MCA “S” tile. “The owners liked the idea of an Energy Star rebate and we really liked the look of the tiles. We have used MCA tiles on other hotel projects and always experienced success.”
California building codes are adopting the energy saving regulations with flat roofs needing to be Energy Star rated by 2005 and steep slope by 2008. “We are looking at other factors beyond color,” confirmed Suzuki. “Clay tiles provide natural air space between the roof deck and the roofing materials. We are studying the effects of this natural air space and how it may help provide natural ventilation.”
All of MCA’s standard styles, including the one piece “S” mission, straight barrel mission, Corona tapered mission, and turret tile, offer Energy Star-rated colors.
The range of colors already includes natural red to white buff and regency blue to weathered green. It is one of the most diverse ranges of Energy Star-rated colors in the industry. Homeowners, building owners and roofing contractors are discovering this new option in California and throughout the Western States.
MCA tile can help achieve credits with Leadership in Energy and Environmental Design (LEED) in the Green Building Rating system. You can receive points in the Energy and Atmosphere section and in the Material and Resources section of the Rating System. Visit the U.S. Green Building Council at www.usgbc.org for more information. •••