Demonstrations are sought of innovative window retrofit solutions that can be installed with minimal occupant disruption, improve occupant comfort, and offer lifecycle cost savings. Proposals should include whole-building analysis to consider the impact of improved building envelope thermal performance on HVAC system sizing and configuration. It is anticipated that combining window upgrades with HVAC replacement will result in better overall technoeconomic performance.  

Solutions with the following characteristics are of interest: 

• Ability to retrofit/upgrade windows of an occupied building with minimal occupant disruption. 
• Energy modeling and analysis considering impacts on planned or coordinated HVAC system replacement. 
• Comfort analysis. 
• Analysis and demonstration designed with consideration of future implementation through Energy Savings Performance Contracts (ESPCs) or Utility Energy Services Contracts (UESC). 
• Collaboration/partnering with Energy Services Companies to facilitate transition of successful technologies and integration with future ESPCs/UESCs 

For selected project teams, ESTCP will provide building data to include physical characteristics, hourly electric utility data, and planned HVAC upgrade/replacement schedule. Proposals should describe the process for performing the technoeconomic analysis as the basis for justifying the investment for the proposed window retrofit/upgrade. The analysis should also include sensitivity analysis of the design concept across all American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) climate zones.  

Proposed technologies and methods should have completed all proof-of-principle work. ESTCP supports demonstrations at a scale sufficient to determine the life-cycle operational cost and performance of the technology. 

Efficient, healthy, and reliable buildings are critical to supporting military and DoD civilian staff to live and work safely in DoD facilities. More energy efficient windows and optimized building energy systems reduce annual operating costs and improve occupant comfort.

The DoD has a wide variety of buildings, most of which are 50 years old or older, with single and double pane windows. With the advancement of new secondary glazing technologies, there is growing opportunity to cost-effectively improve building envelope performance, improve occupant comfort, and reduce energy costs. The DoD has more than 500 installations worldwide, with 300,000 buildings, that account for about 30 percent of the DoD’s total energy use. In FY 2023, DoD consumed 204,883 billion Btus (BBtus) of energy and spent approximately $4.7 billion on installation energy, which included $4.5 billion to power, heat, and cool buildings. Energy consumption in buildings is significantly driven by the building envelope, as it is one of the primary determinants in how comfort and indoor air quality are maintained. Approximately 35% of energy consumption in buildings is used to maintain a comfortable and safe indoor environment. Building envelope leakages caused by either unconditioned air infiltrating into the building or conditioned air leaking out through cracks/openings in the building, including windows, result in significant increase in building energy use due to increase in heating and/or cooling load. In certain climates, the uncontrolled infiltration also results in humidity and mold issues. According to the Department of Energy (DOE) Building Technologies Office (BTO), infiltration is approximately 10% of US buildings’ total energy consumption.