Numerous U.S. buildings have single-pane windows that do not insulate the building or its occupants as well as double-pane units or other advanced windows. Single-pane windows are also inferior in condensation resistance and occupant comfort. However, complete replacement of single-pane windows with efficient, modern windows is not always feasible due to cost, changes in appearance, and other concerns. Retrofitting, rather than replacing single-pane windows, can reduce heat loss and save roughly the amount of electricity needed to power 32 million U.S. homes each year. One avenue is to replace just the pane itself with an improved windowpane. To be economical, these new types of manufactured windowpanes must be able to be installed into the existing window sash that holds the windowpane in place. To be adopted, they must improve window energy efficiency and other important qualities without substantially affecting the window’s appearance.
Project Innovation + Advantages:
Aspen Aerogels and its partners will develop a cost-effective, silica aerogel-insulated windowpane to retrofit single-pane windows. Silica aerogels are well-known, highly porous materials that are strongly insulating, resisting the flow of heat. The team will advance their silica aerogels to have a combination of high visible light transmittance, low haze, and low thermal conductivity. The team's design consists of an aerogel sheet sandwiched between two glass panes to make a double glazed pane. This silica aerogel-insulated pane will be manufactured using an innovative supercritical drying method to significantly reduce the aerogel drying time, thereby increasing productivity and reducing cost. Aspen Aerogels’ windowpane could be used to replace single panes in windows where thickness or weight preclude replacement with common double-pane units and at substantially lower cost.
If successful, technologies and techniques developed through Aspen Aerogels’ project will enable energy-efficient retrofits for the substantial remaining stock of single-pane windows in the United States. Retrofitting single-pane windows could produce significant economic and environmental benefits. These technologies could help reduce building energy consumption and save money for homeowners and businesses. Consumers adopting these retrofits could also benefit from improved window performance, including greater comfort and condensation resistance in cold weather and better soundproofing. Finally, by consuming less electricity, natural gas, and/or heating oil to warm a building, these technologies reduce the greenhouse gas emissions associated with using these energy sources.