Air Sealing a Historic Building in Plymouth, MA with AeroBarrier
When the Mount Pleasant school in Plymouth was built 115 years ago we doubt that air-sealing was a priority. In fact, from our testing we know that it wasn’t.
This school was recently converted to 11 units of residential units between 467 and 1200 square feet. We worked with the builder and HERS Rater from the permit stage of the project to ensure a successful result given some of the energy challenges of the project. This school has exposed brick exterior walls with no insulation, and the proposed project planned to keep those elements.
How can a unit with uninsulated walls increase its energy efficiency?
We knew from our pre-construction testing that the units were already extremely leaky, one unit was 44.6 air changes per hour (ACH). That number had to come down if these units were going to be more efficient.
Using AeroBarrier as the sole air-sealing method, the average leakage per unit by 54% from pre-construction to post-construction. The unit that started as 44.6 ACH ended at 9.5 ACH, a 78% reduction in air leakage!
Ascetics were important as the visual integrity of the exposed brick was a chief concern of the builder. As you can see from the photo, AeroBarrier was able to seal the leaks and leave the rest of the brickwork untouched. The air sealing was completed prior to some cosmetic re-pointing of the brickwork. The spots where AeroBarrier sealed air leaks could be easily touched up lightly with mortar.
The project received over $70,000 from the local utility sponsor, Mass Save, for energy efficient upgrades.