New green technology squeezes out building leaks

Apr 10, 2013
New green technology squeezes out building leaks
Curtis Harrington, right, and student assistant Mari Thomsen from the UC Davis Western Cooling Efficiency Center prepare a blower door to test a new aerosol sealing technology. Credit: Paul Fortunato/UC Davis WCEC

(Phys.org) —A new building-sealing technology developed by researchers at the University of California, Davis, will get a real-world test today at a Habitat for Humanity home in Stockton, Calif.

Developed by scientists at the UC Davis Western Cooling Efficiency Center, the is designed to take the guesswork out of sealing leaks, which account for roughly 30 percent of the energy used to heat and cool a building.

Previous testing has shown that the UC Davis aerosol sealing technology can reduce available leaks by 50 percent. With further improvements, the researchers think it has the potential to bring leakage down to nearly zero.

The technology uses a compressed nitrogen system to push a sealant through five . Once sprayed into a pressurized environment, the sealant becomes a foggy mist of aerosolized particles. These particles move toward wherever air is escaping and seal the leak.

"Kind of like a race car run amok, the particles skid out of the air, hit the leak and stick," said project manager and Western Cooling Efficiency Center associate engineer Curtis Harrington.

"The technology has the potential to seal a building better, faster and cheaper than any manual process. It finds and seals the leaks for you—and, through a software system that tracks the sealing process, it provides automatic verification that it's sealed," Harrington said.

The system takes roughly one hour to seal a 1,200 square-foot home, identifying leaks that escape the .

"And you don't have to have someone running around using a caulking gun," said WCEC assistant engineer Nelson Dichter.

Since April 2012, the UC Davis center has tested the technology in three new Habitat for Humanity homes in San Joaquin County and one retrofit home in Davis, Calif.

The California Building Code requires that all new be zero net energy by 2020. The new UC Davis sealant technology could become a tool to help Habitat for Humanity and other builders reach that goal.

The new system builds on previous research by Western Cooling Efficiency Center Director Mark Modera, who developed a system to seal duct leakage with aerosol particles. The new technology uses a similar process to seal leaks in building envelopes—the outer shell of a building, such as the walls, doors and windows that separate the interior and exterior environments.

"The mission of the Western Cooling Efficiency Center is to reduce cooling energy use and peak power demand," said Modera, a UC Davis professor of civil, environmental and mechanical engineering. "However, when we see an opportunity to impact both heating and cooling, in this case by reducing excess air infiltration, we take advantage of it. Once we have worked out the kinks in single-family applications, we expect that this technology will have widespread applicability, not only in the buildings sector, but in many other situations in which a tight enclosure is desired."

While some ventilation is needed to maintain healthy indoor air quality, the UC Davis center's goal is to get the system to minimize leakage by as much as possible—ideally, to zero—and then adjust the system to account for ventilation needs.

The scientists primarily have focused on vacant, new buildings for the testing process to ensure the sealant does not seal or coat residents' belongings.

Once the seals are made and the building is flushed, the low-VOC sealant provides a safe environment for inhabitants. However, breathing aerosols while the sealant is being administered is not recommended. When entering the building during this time, installers wear appropriate respirators.

Explore further: Pollution top concern for U.S. and Canadian citizens around Great Lakes

add to favorites email to friend print save as pdf

Related Stories

UC Davis challenge produces a better air conditioner

Aug 14, 2009

The first certified winner of the UC Davis "Western Cooling Challenge" is Coolerado Corp. of Denver. Recent federal tests showed that their five-ton commercial rooftop unit should be able to air-condition a typical big-box ...

Keeping cool using the summer heat

Jan 23, 2009

(PhysOrg.com) -- While most Australians are taking care to shield themselves from the harsh summer heat, scientists from the CSIRO Energy Transformed Flagship are working on ways to harness the sun’s warmth ...

Recommended for you

Obama launches measures to support solar energy in US

Apr 17, 2014

The White House Thursday announced a series of measures aimed at increasing solar energy production in the United States, particularly by encouraging the installation of solar panels in public spaces.

Tailored approach key to cookstove uptake

Apr 17, 2014

Worldwide, programs aiming to give safe, efficient cooking stoves to people in developing countries haven't had complete success—and local research has looked into why.

User comments : 0

More news stories

LinkedIn membership hits 300 million

The career-focused social network LinkedIn announced Friday it has 300 million members, with more than half the total outside the United States.

Researchers uncover likely creator of Bitcoin

The primary author of the celebrated Bitcoin paper, and therefore probable creator of Bitcoin, is most likely Nick Szabo, a blogger and former George Washington University law professor, according to students ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...