Lawrence Berkeley National Laboratory

Thin-triple pane windows are coming down in price due to some unprecedented changes in the window manufacturing industry, including the recent expansion in the number of U.S. manufacturing lines producing thin-triple pane windows. These insulating glazing units (IGUs) can provide the performance of a traditional triple-pane window with the thickness of a double-pane IGU, allowing them to drop into double-pane window frames in existing homes. More importantly, U.S. window makers can use them in place of double-pane IGUs in their high-speed production lines, paving the way for lower cost, high-performance windows for high-volume U.S. home builders. This paper will touch on these developments and the U.S. Department of Energy (DOE) research that led to them. Recent energy modeling analyses of single-family and multi-family homes are presented showing how thin triples can be a cost-effective tradeoff against other envelope measures to help builders in mixed and cold regions meet the higher Energy Rating Index (ERI) requirements of recent energy codes. Non-energy benefits of thin triples are also addressed, including resiliency, sound mitigation, condensation control, and comfort sections.