Reports

Numerous organizations have been involved in research efforts aimed at collecting data and increasing the knowledge base of the characteristics of window attachments and how users interact with them.

The valuable information gleaned from this research is available in the reports located below. These reports are also available for download in PDF format.

Window Attachments: A Call to Action

October 2016, AERC (Updated September 2017)
Aimed at utility programs, this report outlines the energy saving benefits that window attachments provide, the market size for the product category, and the potential impacts of an energy certification program.

Residential Windows and Window Coverings: A Detailed View of the Installed Base and User Behavior

September 2013, D+R International
Sponsored by DOE, this report on the window attachment market included a behavioral study on consumer usage patterns of window attachments.

Low-E Storm Windows: Market Assessment and Pathways to Market Transformation

June 2013, Pacific Northwest National Laboratory
Field studies sponsored by the U.S. Department of Energy (DOE) have shown that the use of low-e storm windows can lead to significant heating and cooling energy savings in residential homes. This study examines the market for low-e storm windows based on market data, case studies, and recent experience with weatherization deployment programs. It uses information from interviews conducted with DOE researchers and industry partners involved in case studies and early deployment efforts related to low-e storm windows. In addition, this study examines potential barriers to market acceptance, assesses the market and energy savings potential, and identifies opportunities to transform the market for low-e storm windows and overcome market adoption barriers.

Global Lighting Performance

January 2015
This Swiss Federal Office for Energy study focused on the use of movable shading devices in offices and their impact on indoor daylighting. The research explored usage patterns, attachment orientation, and the role of automation on the optimal use of sunscreens. The results demonstrate significant energy savings as result of automation.

Mind the Gap: Summary of Window Residential Retrofit Solutions

2016, Joseph Petersen, Katherine Cort, Sarah Widder, Pacific Northwest National Laboratory
Thomas Culp, Birch Point Consulting, Greg Sullivan, Efficiency Solutions

This paper reviews various window retrofit options, the most recent field test and modeling data regarding their performance and cost-effectiveness, and discuss future rating efforts. This information is useful for utilities and energy-efficiency program managers to help effectively implement incentive measures for these technologies.

Energy Savings from Window Attachments

October 2013, Lawrence Berkeley National Laboratory
This DOE-sponsored study conducted by LBNL used the installed base and user behavior data collected from D+R International’s Residential Windows and Window Coverings report to estimate the energy performance of different window attachment product categories. This modeling study evaluated the thermal and optical properties of eleven window attachments for twelve cities, four residential building types, two HVAC systems, and three baseline window types. The results of the study allowed researchers to make generalizations about the energy performance of window attachments to help demonstrate their energy savings potential.

Saving Windows, Saving Money: Evaluating the Energy Performance of Window Retrofit and Replacement

This study from the National Trust for Historic Preservation builds on previous research and examines multiple window improvements options, comparing the relative energy, carbon, and cost savings of various choices across multiple climate regions. Results of this analysis demonstrate that a number of existing window retrofit strategies come very close to the energy performance of high-performance replacement windows at a fraction of the cost.

Thermal and Optical Properties of Low-E Storm Windows and Panels

July 2015
This study conducted by Pacific Northwest National Laboratory aims to characterize the key energy performance properties of clear and low-e storm windows and panels when installed over different types of primary windows. The study presents the representative U-Factors, solar heat gain coefficients, and visible light transmittance properties of the combined applications of various storm windows over single- and double-pane windows with nonmetal and metal framing. Both fixed and operable windows and panels were evaluated in the study.

Researchers at Architectural Testing, Inc. conducted detailed thermal and optical simulations using WINDOW and THERM software in accordance with National Fenestration Rating Council (NFRC) procedures but also accounting for how storm windows and panels are realistically attached to base windows. The study found that low-e storm panels could reduce U-Factor by 59 – 64% with low-e storm s over single pane windows, and by 43-57% over double pane windows. The authors also noted that storm windows and panels help to reduce air leakage through existing windows, particularly windows that are older.

Database of Low-e Storm Window Energy Performance across U.S. Climate Zones

September 2014, Pacific Northwest National Laboratory
This is an update of a report that describes process, assumptions, and modeling results produced Create a Database of U.S. Climate-Based Analysis for Low-E Storm Windows. The scope of the overall effort is to develop a database of energy savings and cost effectiveness of low-E storm windows in residential homes across a broad range of U.S. climates using the National Energy Audit Tool (NEAT) and RESFEN model calculations. This report includes a summary of the results, NEAT and RESFEN background, methodology, and input assumptions, and an appendix with detailed results and assumptions by climate zone.

Evaluation of Low-E Storm Windows in the PNNL Lab Homes

May 2014, Pacific Northwest National Laboratory
This report describes whole home experimental research conducted in support of the Building America’s Low-e Storm Window Adoption program. The purpose of the project was to evaluate the energy savings potential of installing low-e storm windows over typical double-lane clear aluminum frame windows in the Pacific Northwest National Laboratory’s (PNNL) matched pair of Lab homes.

High Performance Dynamic Shading Solutions for Energy Efficiency and Comfort in Buildings

May 2015 – This European Solar Shading Organisation (ES-SO) funded study explored the energy performance of shading systems and their impact on overall building energy performance. The study analyzed thermal and optical properties for numerous combinations of glazing and shading (interior and exterior). The results of this study highlight the impact of solar shading on heating and cooling loads, energy savings, and CO2 reduction potential in European buildings.

Low-E Storm Windows Provide a New Way to Solve the Window Conundrum

December 2015, Efficiency Vermont
This report details a 2015 pilot project by Efficiency Vermont to increase customer awareness and eliminate the incremental price barrier by marking down the price of Low-E glass storm windows to the price of clear glass storm windows at Lowe’s and The Home Depot stores in Vermont. Marketing materials developed for the pilot include stack-outs and other point-of-purchase materials, and Efficiency Vermont reached out on social media to make customers aware of the promotion. Overall storm windows sales increased by more than 37 percent and sales of Low-E storm windows increased by 337 percent during the 2015 pilot period in comparison to the same period in 2014.