This is a recent Instagram post, an update to the AeroBarrier blog I posted back in September.
Some of my construction education comes from websites I trust. Sites like Building Science Corporation and Green Building Advisor. Another of my favorites is the Minnesota Center for Energy and Environment. www.mncee.org One of the projects I’ve taken an interest in is their research on aerosol envelope sealing in new home construction, which has been ongoing since 2016. The project will be completed in 2019. They just posted a research update of their work. From their latest update:
“The AeroBarrier sealing has reduced house leakage by an average of 75% and produced an average tightness of 0.75 ACH50. For 40% of the houses, the tightness is less than the passive house requirement of 0.6 ACH50. The results show that poly sheeting is not required as an air barrier when houses are sealed with AeroBarrier, house leakage tests conducted at the end of construction indicate little change in the house leakage, versus when they were simply AeroBarrier-sealed.”
The typical new house I blower door test in Minnesota averages around 2.25ACH50. Almost all the homes I test utilize either closed cell spray foam or polyethylene sheeting as the main air control layer. The MNCEE is suggesting that poly may be eliminated when using the AeroBarrier process. (I would like to see the use of poly reduced.) I know there are questions about durability of the air sealing product, especially over time. I have also heard concerns about the sealants effect on health, though I think there is less of a health risk associated with AeroBarrier than high pressure spray foam applications.
I was fortunate to watch the AeroBarrier process first hand last spring. A new home which started at a little over 3.5 ACH50 was reduced to .39 ACH50 in just a few hours. I get that there are builders, some of whom I follow, who can achieve that level of air tightness with their new builds. Those homes will not have durability or health concerns, but many builders for many reasons are not able to meet those numbers. This process could get us to that next level.
For the record, I have no financial interest in AeroBarrier, it’s just a product and process I’m interested in. Read my full Aerobarrier blog here and much more in depth information can be found at the MNCEE website.