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. Window performance can be improved either by transparent, adhesive products that can be applied directly onto existing windows or by manufactured windowpanes that can be installed without replacing the window sash that holds the windowpane in place. Innovative technologies to enable inexpensive, high-performing products in these two categories are needed to accelerate effective retrofit options.
Project Innovation + Advantages:
Argonne National Laboratory (ANL) with its partners will develop a transparent nanofoam polymer that can be incorporated into a window film/coating for single-pane windows. The transparent polymer-nanoparticle composite will be applied to glass, and will improve the thermal insulation and the soundproofing of a window. Key to this technology is the generation of small and hollow nanometer-sized particles with thin shells. These will be embedded in a polymer with a carefully controlled structure and uniform dispersal of nanoshells in the polymer matrix. Competing approaches such as those used for silica aerogels have limited ability to fine tune the material's structure, resulting in materials with weaker mechanical strength, difficulties with transparency, and high processing costs. ANL will develop materials fabricated with self-assembly and a level of precision that allows careful prediction of how light and heat transmit through the material. The team also plans to introduce ultrasound-enhanced continuous processing techniques to manufacture the nanofoam at low cost and with high transparency without undesired haze and enhanced sound isolation capabilities. ANL predicts that the technology will enable an inexpensive window film that can be installed by the homeowner to upgrade a single-glazed window to double-glazed performance at about 25% of the cost.
If successful, ANL’s innovations 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.