This breakthrough enables window producers to meet the growing demand for R-5 windows with less expense and less disruption to their manufacturing operations, compared to producing R-5 triple-pane IG windows.
To achieve R-5 ratings (U-values of 0.22 for operable windows and 0.20 for non-operable windows), manufacturers have traditionally been required to produce triples. However, by combining Duralite with thermally enhanced frames (such as the EnergyCore™ window system by Mikron), argon gas filling and low-emissivity (low-e) glass coatings, manufacturers can realize R-5 ratings in a double. This combination of components yields a 0.20 center of glass U-value, which results in a total window U-value of 0.22 – or R-5. That rating is up to 40 percent more efficient than today’s ENERGY STAR® windows and aligns with the Department of Energy’s R-5 Windows Volume Purchase Program.
Compared to R-5 triples, R-5 doubles are less expensive to produce, as they require fewer raw materials, including less glass, spacer material and gas filling. Doubles weigh less than triples, which makes them less expensive to transport and easier to install. Less weight also enables manufacturers to use lighter grade hardware. In addition, to meet R-5 demands producers do not have to reconfigure their traditional double-pane window manufacturing lines to accommodate triple production.
“A number of market forces are driving the demand for high-performance, energy-efficient windows, including increasingly stringent ENERGY STAR and LEED home specifications. Triples will certainly meet a portion of that demand,” said Ric Jackson, director of marketing and business development at Truseal. “However, R-5 doubles give manufacturers an alternative option that is less disruptive to their operations and less expensive to produce. The distribution channel can pass those savings down the line to consumers, enabling homeowners to meet their desired home energy-efficiency goals more economically.”
Truseal’s R-5 double-pane window design requires a low-e soft coating on glass surface 2 and a pyrolytic low-e coating on glass surface 4. (The four glass surfaces in a double are numbered from the exterior to the interior of a home.) The design also requires argon gas filling, which accounts for as little as 1 percent of the total raw material cost of the window. R-5 values are not possible in traditional doubles, even when using better insulating rare gases like krypton or xenon, which may add up to $50 to the manufacturing cost of a typical double-hung window.
Simulations for Truseal’s R-5 double-pane window design were performed by Enermodel Engineering Ltd. Using Windows 5.2 and Therm 5.2 as per NFRC 100.
About Truseal Technologies, Inc.
Truseal Technologies, Inc., headquartered in Solon, Ohio, and part of the Quanex Building Products Corporation, is one of the world’s leading manufacturers and marketers of insulating glass (IG) products and systems. Truseal produces superior IG warm edge spacer systems with consistent after-sales service and a warranty program for qualified window fabricators. In addition, with a wide variety of equipment platforms, Truseal provides customers with value and efficiency in their window fabrication operations. Truseal’s trademarks include: Duraseal™ and Duralite®, both part of the company’s Dura Platform; Envirosealed Windows™, which feature Dura Platform spacers to insulate homes and reduce energy consumption; and Decoseal™, a spacer system designed for use in decorative windows with multiple air spaces. For more information, visit www.Truseal.com.
Truseal Technologies, Inc.