May 25, 2016

Remember when we were all taught about the four basic food groups and how meat and milk were essential to our good health? The rules on that one have certainly changed. How about the rule that bigger is better? Tell that to cell phone manufacturers and laptop makers.

The rules regarding home energy savings are also changing. New technologies and shifting realities are showing us that what we once believed may need some rethinking. If you look at the list of energy-saving tips offered by experts just five or six years ago, the idea of duct sealing, for instance, was virtually absent. Instead, we were taught that projects such as replacing windows or insulating walls offered the most effective energy-saving results.

It’s not that experts didn’t know that leaks in residential ductwork were often the single biggest source of home energy waste. It’s just that there really wasn’t an effective solution to the problem. Sure, you could use tape or mastic to manually seal some of the leaks. But most of a duct system is located behind drywall, under insulation, in tight attic spaces or other hard to access locations. 

So, with few if any viable solutions available, the problems associated with duct leakage were virtually ignored and advice to homeowners continued to focus on turning off lights and investing in Energy Star appliances. We were resigned to living in a world where the average home lost about 30 percent of its heating and cooling energy through leaks in the ductwork.

Now that aerosol-based duct sealing technology has arrived, the answer to how to address this issue seems almost obvious. While traditional duct sealing methods work by covering leaks from the outside of the ductwork, this new approach would be the first to seal leaks from inside the ducts. If you could get sealant to work from the inside, the problems associated with accessibility would be solved. Walls and insulation would no longer be an obstacle. Sealing in tight attic spaces would be a breeze.

And that’s exactly what the researchers did. The sealant came in the form of an aerosol mist that delivers microscopic particles of adhesive directly to the leaks. The sealant particles cling to the edge of the holes and then to other sealant particles, quickly forming a permanent seal around the entire leak.  The technology, dubbed “aeroseal,” met all the initial criteria set out by the DOE and the research team. It is safe, it doesn’t coat the interior of the ductwork, and it pays for itself in 2.5 – 7 years (compared to upgrading windows at 70 years and wall insulation at 90). Most importantly, it’s highly effective – typically sealing 95% of leakage.

While duct sealing still is not on top of the list for most energy-minded Americans, it’s quickly getting there. Now that there is an effective/cost effective solution, the rules are beginning to reflect this new reality. A growing number of energy advocates – from the DOE and the EPA to local utility companies and green building certifiers – have begun to add duct sealing to the top of their recommended list for homeowners looking to reduce their energy bills and increase indoor comfort.

Times change and innovations often reset the rules of the game. That is certainly the case when it comes to energy efficiency. With effective duct sealing technology a reality, duct sealing has quickly risen to the top of the list of things we can do to reduce energy costs. It’s easy to have done, it’s highly effective and it provides one of the fastest ROI’s you’ll find for any home improvement project. Something to consider the next time you’re turning on the air conditioner or putting another blanket on the bedside.

John Dixon is a freelance writer headquartered in Portland, Oregon. He has published a number of articles on issues related to green building, sustainability and energy-saving technologies.

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