WindowDressers is pleased to announce that with the help of WindowDressers Board Member and University of Maine Orono Professor of Economics, Sharon Klein, we now have updated and more detailed information about the energy and emissions savings of our inserts.

Our research shows that, in a typical house, one medium 11-ft2 pine insert (30” x 52”) may save an average of 8.5 gallons of heating oil (0.8 gallons/ft2) every year, for an estimated savings of $15 – $43 per year, depending on variations in fuel price. Our inserts generally pay for themselves in two heating seasons or less. 

Savings may vary based on outside temperature, whether you have single- or double-pane windows, and what type of heating fuel you use. Our estimates are based on 7,074 heating-degree-days (median historical value for Bangor, Maine 2010-2021), a standard fuel oil-fired furnace (78% efficiency), window insert R-value of 2.0, and averaged results for single- and double-pane existing windows (R-value of 0.91 and 1.93, respectively).

For more detailed information, access the links below: 

Public window insert energy emissions model 2023 – you can download this Excel spreadsheet and change the inputs to model your own scenarios. Make sure to start by reading the Instructions tab.
WindowDressers Energy Emissions Money Savings Estimates March 2023 – you can download this Excel spreadsheet to see how we calculated our estimates of annual and cumulative energy, fuel, and emissions savings.

WindowDressers 2022 Impact Chart