Aerogel is a material with almost superhuman insulating properties (up to R-10 per inch), made of 98 percent air. It’s not a gel—but is initially made with gel, to create a super-dry lightweight translucent material that looks, quite literally, like blue smoke. Until now, aerogels have been specialty products, used to insulate space shuttle tiles and winter jackets for well-off kids with seasonal ski passes.
Recently, however, some companies have begun to offer aerogel insulating products for home construction. For example, ThermaBlok, is a ¼-inch thick, 1 ½- inch wide thermal break that you attach to wood or metal studs before adding drywall. The company claims that this system—a nice upgrade for conventionally framed and insulated stud walls--can result in a 40 percent overall wall R-value increase.
For special insulating challenges, such as retrofitting a brick building or insulating a concrete block, Aspen Aerogels, offers Spaceloft blankets. This product can be applied to interior or exterior walls, acting as both thermal break and insulator. Cabot Corp. offers a similar Thermal Wrap blanket. Aerogel is still quite expensive to make and that cost is passed along to the user, so it’s not likely to replace bulk insulation anytime soon. Researchers are looking at ways to replace some of the more costly silica components with bio-based materials. If successful, that could bring prices down considerably.