Energy Commission-Funded Product Delivers Tightly Sealed Building Envelopes

Homes are generally designed to keep the indoors in, and the outdoors out. But that doesn’t always happen, especially with older homes.

Leaks in a building’s envelope – roofs, walls, and floors – waste money and energy and can be a source of poor air quality. Sealing the envelope though, can be a time-consuming, difficult, and not always effective process that typically involves caulk, spray foam, weather stripping or other materials. But a new product on the market, developed with the help of research grants from the California Energy Commission and the U.S. Department of Energy, is changing that.

AeroBarrier is a portable automated process for sealing gaps and tightening a building’s envelope. Using pumps, hoses, and aerosol-mist nozzles, the system sprays a cloud of waterborne acrylic droplets into a pressurized room. The pressure forces air to escape through leaks, and as it does, the sticky particles follow, coagulate around openings and harden to seal them. A computer controls the temperature, pressure, humidity, and distribution of the sealant while technicians monitor the progress in real time.

AeroBarrier can seal holes as tiny as a human hair and as large as a half inch across, and tests show it can reduce leakage by up to 90 percent in new buildings. Sealing a typical single-family home takes about four hours from setup to completion and costs far less than traditional methods. The process is GREENGUARD Gold certified, meaning it meets or exceeds low emissions standards for volatile organic compounds in indoor spaces.

AeroBarrier hit the commercial market in January after five years of research and development at the University of California, Davis Western Cooling Efficiency Center. The project received support from the Energy Commission’s Public Interest Energy Research Program and the Department of Energy’s Building America program. It is licensed to a company called Aeroseal that manufactures, sells and distributes the machinery and sealant.

Successful early demonstrations of AeroBarrier in California homes proved its effectiveness and drew the attention of builders around the country. Arizona-based home builder Mandalay Homes was an early adopter. During beta testing of the technology in 2017, the company volunteered to try it out on a few dozen new homes it was building. It now uses AeroBarrier on every home it builds.

According to Mandalay, in less than three hours, a two-person team reduced the air leakage of a 2,200 square-foot, three-bedroom house by an additional 68 percent over what was accomplished by traditional sealing methods that required more than 20 hours of labor.

Earlier this year, AeroBarrier received the best in show award at the National Association of Home Builders’ International Builders’ Show.