By hybrid we mean that this project combines energy efficiency with energy production. This project began as a solar site assessment with Puget Sound Solar. Through this visit we gained a better understanding of the homeowners goals for the home and it was determined that a home performance evaluation was a good starting point. On our follow up visit to the home we found some very significant issues that were effecting the comfort and efficiency of the home.
Here we can see uninsulated knee walls where the cathedral ceiling meets the attic
This is a picture of the same knee wall from the attic side showing bare drywall with no insulation
This 4'x8' section of attic is a dropped soffit above the shower which is open to interior walls all around its perimeter. Additionally you can see that the attic insulation does not reach the tops of the 2"x6" joists providing a limited amount of thermal performance for the home.
Retrofit
Based on the findings from our home performance evaluation and the customer's goals for energy generation we proposed a scope of work which included air sealing and insulating the attic to R-50, insulating the knee wall with R-13 fiberglass batts supported by R-5 ridged foam, and installation of a 3.36kw Sanyo photovoltaic system with Enphase inverters.
Results
Key benefits from the retrofit include:
- 25% reduction in air leakage
- 30% reduction in heating load
- 50% offset of electrical load
-Candis Litsey