Aerogels on the Rise

In January, a substance called "Nanogel" was highlighted as one of the best solutions to improving thermal and acoustic insulation in daylighting applications at Bau 2005, a biennial construction expo in Munich hosting 200,000 visitors from around the world. Manufactured in Frankfurt, Germany, by Cabot, Nanogel is an example of an emerging class of translucent material made of silica aerogel, a lightweight and highly porous foam that is 90 percent air. Discovered by American chemist Samuel Kistler in the 1930s, aerogels did not find widespread commercial use until a few years ago; now building product companies including Kalwall, GE Advanced Materials Structured Products, Westcrowns, and Scobalit are using Nanogel to make skylights, curtain wall, and glass block. Alex Wilson, executive editor of Environmental Building News, says that while aerogel-based products exhibit insulation values of up to R-8, they have yet to gain a foothold in construction because they are relatively expensive and translucent rather than transparent, limiting their range of uses. Wilson speculates that aerogel will find greater acceptance only "when we begin to value energy conservation more highly." Anna Holtzman