Date of Award

Summer 8-11-2017

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Arts (MA)




Sharon Klein

Second Committee Member

Caroline Noblet

Third Committee Member

Cynthia Isenhour


Residents of Maine face a large monetary expense to heat their homes in the winter. In Maine it takes 540 gallons of heating oil each year to heat a typical home [1]. Interior window inserts may be a practical solution to improve comfort, save money, and consume less environmentally harmful fossil fuels during cold winter months. The window inserts discussed in this paper are custom measured to fit into a window and consist of a wooden frame that is wrapped in two layers of polyolefin film and weather stripped for a snug fit. Commercial inserts cost $20-$36/square foot, or approximately $300-$540 for a 36” by 60” window [2]. However, there is a growing movement in Maine to reduce costs by harnessing the power of community volunteers. WindowDressers is a non-profit organization in Rockland, Maine that helps community organizers in towns throughout the state provide inserts for one-tenth of the price ($1.65-$3.68/square foot) of commercial inserts. In addition, 25% of inserts are allocated to low-income customers for a reduced rate ($10 for 10 inserts). Customers that purchase inserts also volunteer time to work to build and assemble them with other members of the community. This is part of a growing movement of community energy that works through grassroots movements as opposed to traditional “top down” approaches to achieve energy related goals.

Survey data are used in this thesis to show customers are participating to conserve energy, live comfortably, save money, benefit the environment, and because they value the sense of community with the project. Volunteers are participating to help others achieve the same goals. Ninety-six percent of participants reported being satisfied with their overall experience, and 68% of volunteers report having a better experience than they were expecting. Survey data are also used to demonstrate that most customers are not reporting a direct rebound effect, or lower than expected energy savings from an energy efficiency improvement. After the inserts are installed in a home, more customers reportedly turn their thermostats down rather than up. The ability for the inserts to reduce drafts and make rooms feel warmer are credited for this.

We also predict the cost, energy, and emissions savings: a typical home with ten 36” by 60” inserts is estimated to save 35 gallons of heating oil per year, which results in $105 per year in savings and a simple payback period of 3.9 years on their investment for full price customers. The typical Maine home is also predicted to save 357 kilograms of carbon dioxide, 14 grams of methane, and 3 grams of nitrous oxide per home, per year. Historical fuel oil consumption data are used from three WindowDressers customers to estimate the median of their annual fuel oil energy savings to be 17% as a result of window inserts. The historical heating fuel analysis shows a median of 128 gallons of heating oil being saved per household during the winter of 2016 - 2017, resulting in an estimated $326 of household savings 1,300 kilograms of carbon dioxide, 52.5 grams of methane, and 10.2 grams of nitrous oxide per household. Finally, this thesis compares historical consumption for two customers to the predicted energy savings model designed for their homes. We find that their consumption falls along the same range of predicted savings.

Mistro_SupplementalMaterials.pdf (1192 kB)
Full Versions of the Survey Questions