March 12, 2021
After several years of a research and development relationship, one of the largest window and door replacement companies in the U.S. announced the national launch of a new high-performance glass option for select replacement windows. The new glass option offers a “thin-glass” triple-pane glazing element that makes the window five times more insulating than a single-pane window, based upon a typical single-pane wood window performance of 1.0 Btu/hr-ft 2 -℉.
The Department of Energy’s (DOE’s) Lawrence Berkeley National Laboratory (Berkeley Lab) has been working with Andersen Corporation and its window replacement division, Renewal by Andersen, for several years to build and test enhanced prototypes of the thin-glass triple-pane window suitable for large-scale manufacture. Renewal by Andersen’s national launch is a significant milestone in Berkeley Lab’s effort to advance from a research prototype to a marketable product that can provide energy savings across the U.S.
“Our successful relationship with Andersen Corporation goes back to the 1980s when we collaborated with them on the first big change in window energy efficiency technology – low-emissivity window coatings,” said Stephen Selkowitz, now a retired Affiliate in Berkeley Lab’s Energy Technologies Area (ETA). “Most window companies were reticent to add the new low-E coated glazing in their windows but Andersen saw the potential and was one of our first allies to adopt the new technology. Now, more than 30 years later, those low-E windows have captured almost 90% market share across the entire industry. We hope that this relationship with Andersen and Renewal by Andersen’s recent market launch of the thin-triple glass option will have similar impacts. We believe this technology will help to create billions of dollars per year in new energy savings in buildings across the country.”
The full-service window replacement division of Andersen Corporation, Renewal by Andersen, plans to market thin triple-pane glass direct to homeowners. “Our commitment to being good stewards of our natural resources is a core value of Andersen Corporation,” said Director of Quality and Research at Renewal by Andersen, Kate Graham. “By investing in thin-triple pane glass and marketing the benefits to our customers, we believe our homeowners will help reduce energy consumption and see additional savings in home energy costs and experience a more comfortable living space. We are grateful for our long-standing relationship with Berkeley Lab. We hope Andersen’s leadership embracing this innovation will encourage other manufacturers to
follow our lead and invest in new technologies that will continue to revolutionize our industry.”
Berkeley Lab, which has an extensive history of success in window research and development, invented and patented the “thin-triple” window concept 30 years ago. Conventional triple-pane windows have existed on the market since the early 1980s, but they have not been widely adopted because they required wider, heavier, more costly frames. What differentiates Berkeley Lab’s thin-glass triple-pane window design from other triple-pane windows is that they are designed to easily replace existing double-glazed windows without having to modify the window frame, making them a more cost-effective market-ready technology.
The windows are big energy savers in a wide range of climates, including California. The Berkeley Lab high-performance window team, now led by ETA Principal Scientific Engineering Associate Robert Hart, installed prototype thin-glass windows supplied by Alpen High Performance Products, a small innovative window company, into a home in Fresno, CA in 2019. That experience helped secure a new grant awarded early last summer by the California Energy Commission’s Electric Program Investment Charge Program that is enabling Berkeley Lab’s team to expand that work with multiple industry partners to conduct demonstration projects in low-income and disadvantaged California communities, and ultimately promote wide-spread adoption of thin-triple windows.
“In addition to these new field demonstrations, we are extending our research and development efforts to other efficient window technology,” said Hart. “We are developing thin-glass quad-pane windows, exploring vacuum insulated glazing, quantifying the comfort benefits and expanding our focus from homes to office buildings, which have enormous additional energy savings potential.”
The Berkeley Lab windows team hopes that the new market announcement from Andersen will be followed by others and will begin to shift design practice in new and retrofit homes to a new generation of more efficient windows. “Our research goal since the 1980s has always been to develop windows that are even better than insulated walls, and these new products get us closer
to that target. Ultimately, we need to get there if we want to help meet the climate goals set by the Paris Climate Agreement and the new 2050 energy/carbon goals of the Biden Administration,” said Selkowitz.
Berkeley Lab’s thin-glass triple pane window research was primarily funded by DOE’s Building Technologies Office, with additional support from the California Energy Commission.
New Berkeley Lab Thin Triple Window Program in CA: newscenter.lbl.gov/2020/07/01/high-performance-windows-to-benefit-low-income-california-communities/
Energy Savings Potentials of Berkeley Lab Thin Triple Window Program:
Technical Updates on Berkeley Lab Thin Triple R&D Program: windows.lbl.gov/triple-glazing-thin-non-structural-center-glass