Publication date: 12/22/2007

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New technology can seal ductwork with aerosol

This being the Christmas season, I am going to write about a part of the government that works to make life better and actually saves you money.

This part of the government produced Aeroseal, a technology that cuts residential and commercial heating and cooling bills by about 30 percent. In doing so, it saves a vast amount of energy and could dramatically cut down on greenhouse gases.

The technology was developed by the U.S. Department of Energy's (DOE) Lawrence Berkeley National Laboratory.

Many of the lab's research activities are fairly arcane, but have practical applications that are licensed to corporations. Recently, they licensed a gene therapy for Parkinson's disease; ion mobility analysis technology for cardiovascular disease indicators; and technology for the cost-effective removal of mercury from coal-fired power plant emissions.

Way back in 1987, the laboratory's Environmental Energy Technologies Division was concerned with the tremendous amount of heating and cooling energy wasted by sloppy residential and commercial ductwork.

It turns out that the ductwork taking the heated and cooled air from the furnace and air conditioner to our living space is so badly assembled that leakage costs consumers about $5 billion a year. That's wasting the equivalent of the energy consumed by 13 million cars.

Dr. Mark Modera, a staff scientist, had the idea that since ducts are often in hard to get to places and are difficult to seal from the outside, an aerosol technology might be developed that would seal the ductwork from the inside.

The DOE and the California Institute for Energy & Environment funded the research in 1990. Within a few years a process was developed by which duct outlets were blocked and very small, sticky vinyl particles dispersed under pressure into the ductwork.

The only way the particles could get out was through the leaks in the ductwork. The particles bumped into and adhered to the edges of the leaks and each other, sealing the leaks. Under laboratory conditions, particles could seal holes as large as 1 inch across. In real-world conditions this was reduced to 5/8 inch.

I have over-simplified the description of the technology and the challenges that had to be overcome to make the idea viable. Particles had to be developed that would adhere to the edges of a hole and to each other, yet not stick to the ductwork.

Special, non-clogging, atomizing nozzles were developed that would shoot the particles under high pressure. Techniques had to be developed to block off and protect the heating and cooling equipment as well as the ductwork grilles.

After years of refinement and testing, residential and small commercial use of the Aeroseal technology was licensed to the Carrier Corp. A specialist company, Carrier-Aeroseal was created to further develop and market the technology. By 2005, some 25,000 residential duct systems had been sealed.

Sealing the ductwork reduced heating and cooling required up to 30 percent and resulted in energy savings of up to $300.

Before Aeroseal seals ducts, homes are tested to determine the actual ductwork leakage. The ducts are then sealed and the home's ductwork is re-tested for leakage. The job is guaranteed for 10 years.

Here are a few real-life results.

ﾕ Building A: a 21-year-old, 1,238-square-foot, two-story home with a two-year-old, 72,000-BTU natural gas heating and 36,000-BTU cooling system.

The home was tested and found to have leaks equaling a 142-square-inch hole. The Aeroseal treatment reduced leakage by 95 percent to 6 square inches. This created a 42 percent improvement in heating and cooling capacity, and actual energy savings of $213 per year.

ﾕ Building B: A 36-year-old, 3,200- square-foot, two-story home with a 72,000-BTU natural gas furnace and a 36,000-BTU cooling system. Initial testing showed leaks equaling an 87-square-inch hole. Aeroseal treatment reduced leakage by 91 percent, leaving the equivalent of 8 square inches of air leakage. Heating and cooling capacity improved 30 percent and actual energy costs were reduced $273.

ﾕ Building C: A 14-year-old, 1,200-square-foot, single-story commercial building with an 8-year-old, 72,000-BTU natural gas furnace and a 36,000-BTU cooling system. Initial testing showed leaks equaling 110 square inches. The Aeroseal treatment reduced leakage by 87 percent, leaving 14 square inches of air leakage. Capacity of the heating and cooling equipment improved 34 percent and actual energy savings was $256.

It's simple. If you want to save money on heating and cooling at the same time you help save the planet, check out the Aeroseal system.

The Aeroseal contractor for Metro Detroit is Safety King, (800) AIR-DUCT. Out state, call Aeroseal of Michigan, (866) 900-SEAL. To find a contractor in other parts of the country, call (800) 772-6459 or click on www.aeroseal.com.

Note: This article was accurate at the date of publication. However, information contained in it may have changed. If you plan to use the information contained herein for any purpose, verification of its continued accuracy is your responsibility.

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