‘Super window’ could save $10 billion annually in energy costs

London’s ‘Gherkin’ [image credit: BBC]

The idea here is that a new type of triple-glazed window would be of identical width and similar weight to an equivalent double-glazed one, thus minimizing compatibility issues.

About $20 billion worth of energy leaks out of windows in the United States each winter—and that’s with double-paned insulating windows installed on a majority of buildings, says TechXplore.

The Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) is now working with manufacturers to bring to market a “super window” that is at least twice as insulating as 99 percent of the windows for sale today and will be ready to achieve mass-market status.

The “thin triple” super window design doubles the thermal performance of current Energy Star-rated double-glazed windows and is seven times more insulating than a single-glazed window.

Berkeley Lab scientists have built and tested prototypes in the lab and are now working with Andersen Corporation, the largest window and door manufacturer in the country, and separately with Alpen High Performance Products, which specializes in energy-efficient doors and windows. Both efforts are looking to build and test enhanced prototypes suitable for large-scale manufacture.

“Our approach is to attack the problem from two sides: to develop both ‘market pull’ and ‘technology push’ forces,” said Berkeley Lab researcher Steve Selkowitz, one of the inventors of the super window concept. “We are working with manufacturers to assist them with their technology challenges while also working with Energy Star, supply-chain companies, and utilities, which can offer rebates and incentives for consumer purchase. Our role is to be a catalyst in facilitating technological innovation and an evangelist in promoting DOE’s energy-efficiency mission.”

Berkeley Lab has a long history of innovation in green building technologies; for example, it recently demonstrated the use of controlled lighting and shading to save energy and is working to make net-zero energy homes a reality. Its work on high-performance windows dates back to the late 1970s when the oil crisis catalyzed new ways to save energy. Berkeley Lab researchers at the time provided the technical support for a brand-new product—a low-emissivity (or low-e) window coating that helps to block long-wave infrared rays—to reach mass-market status. Low-e coatings have gone on to save the country billions of dollars in energy costs.

Selkowitz believes the new thin triple super window could save even more. Current double-glazed windows consist of two layers of glass with a low-e coating and argon gas in the gap between the glass layers to further reduce heat transfer. The innovation of the Berkeley Lab super window is threefold: It inserts a third layer of very thin glass sandwiched between the two layers of a double-glazed window, adds a second low-e coating, and replaces the argon gas with krypton gas, which is much more insulating than argon in the very narrow space between the panes.

While there are other triple-glazed windows on the market, the virtue of this one is that it is the same width and virtually the same weight as existing double-glazed windows. This avoids having to redesign the window sash and frame, which would pose a significant cost obstacle to market penetration.

Continued here.