Rook Energy Solutions had the opportunity to work with Spark Applied Efficiency to do a comprehensive energy retrofit in Yarmouth, Maine. The goal of the homeowner was to get off of oil for their primary heating fuel, and instead heat with a central air source heat pump system with electric backup. In order for this fuel switch to be viable and cost-effective compared to oil, it was necessary to majorly improve the building envelope of this old cottage.
The initial blower door reading of the home was 4200 CFM50 (0.63 air changes per hour). Air movement in the attic and knee wall spaces was excessive due to the poor condition and installation of the 60-year rock wool batt insulation. The basement and crawl spaces were uninsulated and lacking a good vapor barrier causing poor indoor air quality and mold. The air quality was causing problems for the child in the home, who was sensitive to the mold and mustiness being recirculated by the furnace.
Rook Energy Solutions did a full weatherization retrofit of the attics, basement and crawlspaces. Insulation was removed to allow for thorough air sealing of all attic bypasses, and new Thermax rigid board, closed cell spray foam and cellulose was installed. A new vapor barrier was installed over the exposed dirt in the crawlspaces.
The final blower door reading showed our work reduced infiltration by nearly 40% (a 1600 CFM50 reduction). This reduction, along with increased in R-values now allows for the use of a 4-ton heat pump to provide the vast majority of the building’s heating. The homeowner can now enjoy lower energy bills, increased comfort and better indoor air quality for everyone.
Improved dense-packed cellulose in the slopes (above).
Insulation voids eliminated (above)
Air movement through the built-in dressers eliminated (above)
Greatly improved insulation in the rear dormer slope and attic (above)
Air leakage from a hidden chimney chase sealed (above)