I had a call from a customer asking me if we sealed ducts.  He was watching This Old House on TV and the contractors were using equipment that sealed the ducts from the inside.  They stated that this procedure kept duct leakage to 5% or less.  Has anyone ever heard of, seen, or used this procedure. Just curious, I'll stick to mastic, but I always like to keep up with the latest.



Tags: Duct, HVAC, Sealing

Views: 10237

Reply to This

Replies to This Discussion

He's probably talking about Aeroseal http://www.aeroseal.com/

I have no experience with it. One of my customers is definitely a candidate for this.

I would find out what was being sprayed on the inside of the ducts...
The air being blown through the house goes through those ducts...
The homeowner will get to breathe the sprayed on sealant for quite a while.. You want to make sure it's not harmful.
Ira Eisenstein
Keep in mind they were using this on "This Old House" so they probably aren't going to use something dangerous or toxic or harmful to the system. Never heard of anyone using it here in the south.
You also want to make sure there are no motorized duct dampers (for zoning)...
You don't want to "seal" them into one position.
Ira Eisenstein


  • Seal ducts that are inaccessible
  • Seal joist spaces that are used as duct runs to hopefully improve air quality


  • Forget about having the ducts cleaned after they are sealed from the inside.
This product typically can only seal small holes 1/4 inch or less. For the overall cost, your better off buying a bucket of mastic and mesh tape and doing it the old fashioned way. This might be an option for brand new systems but many older ones will have larger holes that this cannot fix.
Thanks for the info.  It may be useful in situations were all the ducts are run through bulk heads in the basement.













We just completed an Energy Upgrade on a home that had the FAU replaced with a 90% sealed combustion unit. The HVAC Contractor who sold our client the FAU the year before, told them their ducts were fine, and he'd just seal them.  We tested the duct leakage at 25%, and the photos reflect the condition of the ducts.  For clients that ask for a sealing option, make sure they know the true condition of their ducts. 

If the product is effective I would think many would benefit from its use- What's the point

of renting conditioned air.Question, can the application process show before and after pix?

Confirmation of the products proper application would be of interest,                                                                   - not just to me but for any customer.

Invented here at LBNL.

More info at this link: http://epb.lbl.gov/aerosol/


Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

SmithWatson commented on SmithWatson's blog post Top 6 Energy Efficient Brands for Gas Furnace and Boiler
"Thank you for your valuable comment Gary.Yes, the product AFUE rating and other numbers are from…"
6 hours ago
Eric Kjelshus replied to Barbara Smith's discussion Eliminating Standing Pilot Light Furnaces
"Biggest pro is to keep the clay or brick or high mass chimney warm  with the 4-8" flame.…"
12 hours ago
Profile IconScott Bloedorn, Matt Macfadden, Lauren Asplen and 1 more joined Home Energy Pros
17 hours ago
Tim Wulling joined David Eggleton's group

1000 Home Challenge

Linda Wigington distinguished between deep retrofits & deep energy reductions, thus expanding…See More
19 hours ago
Gabrielle Rossetti's event was featured

Online Course: ASHRAE 62.2 Ventilation for Single-Family Dwellings at Online - At Your Own Pace

October 15, 2015 at 6pm to November 27, 2015 at 7pm
20 hours ago
Tom White posted videos
20 hours ago
Diane Chojnowski replied to Diane Chojnowski's discussion Solar Decathlon 2015
"Great photos Steven! Thanks for sharing."
21 hours ago
Steven Lefler replied to Diane Chojnowski's discussion Solar Decathlon 2015
22 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service