Single-Pane Highly Insulating Efficient Lucid Designs
The SHIELD Program, short for “Single-Pane Highly Insulating Efficient Lucid Designs,” aims to develop innovative materials that will improve the energy efficiency of existing single-pane windows in commercial and residential buildings. Technologies created through the SHIELD program seek to cut in half the amount of heat lost through single-pane windows in cold weather. These materials would improve insulation, reduce cold weather condensation, and enhance occupant comfort. The technologies could also produce secondary benefits, such as improved soundproofing, that will make retrofits more desirable to building occupants and owners. The program will focus on three technical categories: products that can be applied onto existing windowpanes; manufactured windowpanes that can be installed into the existing window sash that holds the windowpane in place; and other early-stage, highly innovative technologies that can enable products in the first two technical categories.
Commercial and residential heating, ventilation, and air conditioning (HVAC) systems accounted for 14 percent of U.S. primary energy consumption in 2013, and about one quarter of this energy is used to replace heat that leaks through windows in cold weather. Most new installed windows are energy-efficient double-pane units that incorporate a low-emissivity coating on one of its panes to further mitigate heat loss. However, many existing homes and businesses in the United States still have inefficient single-pane windows. Upgrading these windows in existing buildings has been slow due to the cost of replacement, size and weight incompatibilities of double-pane windows with single-pane units, and undesirable changes in the appearance and functionality of double-pane replacements, particularly in historically and architecturally significant structures. Technologies that overcome these barriers and provide affordable, effective retrofits could accelerate improvements in window energy efficiency. Retrofitting single-panes windows would save about 1.3% of domestic energy use and return $12 billion per year to energy consumers. Retrofits will also reduce window condensation on cold days and improve occupant comfort.
If successful, technologies developed through the SHIELD Program 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 environmental and economic benefits. By consuming less electricity, natural gas, and/or heating oil to warm a building, SHIELD technologies could help avoid greenhouse emissions associated with producing and using these energy sources. Moreover, SHIELD 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 better soundproofing and reduced condensation.