Energy efficiency, sustainable products talk of Ecobuild

Sahely Mukerji, Glass Magazine
December 10, 2008
COMMERCIAL, RETAIL, FABRICATION : GREEN, MEETINGS AND EVENTS

The Efficient Windows Collaborative Pavilion at the Ecobuild & AEC-ST Fall conference hosted a number of speakers Dec 10. The conference runs Dec. 8-11 at the Washington Convention Center, Washington, D.C. The exhibit portion of the event takes place Dec. 10-11.

Nils Petermann, project manager, Efficient Windows Collaborative, Washington, D.C., opened with an introduction of his organization. “There are plenty of ridiculous claims out there, such as a 40 percent reduction in energy bills with the use of a certain brand of windows or payment of the difference," he said. "But there are tools that can give users a real idea of energy savings."

The EWC provides information that helps decision makers select energy-efficient windows, Petermann said. Lawrence Berkeley National Laboratory's residential sector tool RESFEN and commercial sector tool COMFEN help users calculate energy performance of windows. More information is available at www.efficientwindows.org and www.commercialwindows.org.

The EWC is a coalition of organizations, companies, and government agencies interested in promoting high-efficiency fenestration products. It comprises the Alliance to Save Energy, Washington, D.C.,  for communications/ marketing activities; the University of Minnesota for information products and technical support; AZS Consulting, Gainesville, Fla., for outreach support; the U.S. Department of Energy for funding; and more than 160 members.

After Petermann, Ray McGowan, technical services manager, National Fenestration Rating Council, Greenbelt, Md., presented an overview of his organization. “The NFRC was created in 1989 to provide standardized methods for determining windows', doors' and skylights' energy performance,” he said. “It’s a unique, educational nonprofit public/private organization representing the Industry, state energy offices, design professionals, utilities and consumer organizations.” NFRC has been a member of the U.S. Green Building Council since 2007.

NFRC’s energy performance ratings include U factor, visible transmittance and solar heat gain. The ratings “ensure complete aggregated performance of frame, glazing and spacer,” McGowan said. “NFRC is the only nationally recognized fenestration rating organization and is required by the IECC [International Energy Conservation Code], ASHRAE and Energy Star.”

Dave Martin, president, Allied Windows Inc., Cincinnati, Ohio, and Jim Nelson, sales manager, Mon-Ray, Minneapolis, were up next to talk about storm windows. “Storm windows or secondary glazing reduces energy losses and costs by 50 percent,” Martin said. “They have a three-to-nine-year payback.” Old buildings with single-glazed windows are the best potential for storm window usage, he said. NFRC does not have any ratings for storm windows, he pointed out.

“Windows lose energy through radiation, transmission, and air infiltration and exfiltration,” Nelson said. “Sixty percent of energy loss through windows occurs through air leakage. The big bang for your buck is in the air leakage. It can’t be ignored. And that’s where you get the most benefit from secondary glazing. When the wind blows parallel, an IG performs well, but when the air flows perpendicular, it leaks.”

A high-performance storm product is a better choice than an IG unit, because the sealant will eventually fail in an IG unit, Nelson said. “IGs are good for fixed windows, but in operable windows, it will fail at some point. With a high-performance storm product that won’t happen.”

Wrapping up the day, Mario Tarquinio, business development specialist, Mid Atlantic Territory, Traco, Bethesda, Md., presented his company’s NexGen technology and NRG products, on display at the show.