Energy consumption in buildings is largely 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 result in significant increase to the building energy use due to increase in the heating and/or cooling load. In certain climates, the uncontrolled infiltration also results in humidity and mold issues. According to Department of Energy (DOE) Building Technologies Office (BTO), infiltration is approximately 10% of US buildings’ total energy consumption.

Identifying the need and opportunity for potential significant savings, ESTCP has funded demonstrations of several innovative, cost-effective and sustainable building envelope technologies that identify, locate and/or reduce the building leakage:

EW-201252, Demonstration Program for Low-Cost, High-Energy-Saving Dynamic Windows by View, Inc.

• This project demonstrated the performance and life-cycle cost benefits for U.S. Department of Defense (DoD) building energy efficiency by using dynamic windows, a new type of advanced “Smart Window” product. These smart windows can automatically tint and untint throughout the day to minimize solar heat-gain in the summer, maximize passive heating in the winter, and maximize the use of natural daylighting throughout the year. The project demonstrated a reduction in HVAC energy consumption by 29% and lighting energy by 62% and the total building energy savings was 28%. Additional details on the demonstration results can be found in the Final Report and Cost & Performance reports available for download on the project webpage.

EW-201511, Automated Aerosol-Sealing of Building Envelopes by University of California, Davis

• This project demonstrated an aerosol-based process for automated sealing of the building envelope. The aerosol envelope sealing process involves pressurizing a building to normal testing pressures while applying an aerosol “fog” to the building interior using multiple air-atomization nozzles located inside the building. As the air escapes through leaks in the exterior shell of the building, the aerosolized sealant is transported to the leaks, and seals them as it tries to escape from the building. The entire process is controlled from outside the building and is capable of simultaneously measuring, locating, and sealing leaks in a building envelope. This project is estimated to be complete by first quarter of 2018.

EW-201512, Demonstration and Cost Analysis of a Building Retrofit using High-Performance Insulation by U.S. Army Engineer Research and Development Center (ERDC), Construction Engineering Research Laboratory (CERL)

• The project demonstrates the use of thermal insulation, Modified Atmosphere Insulation (MAI), to increase the thermal resistance of walls with a marginal increase in wall thickness to reduce wall-related heat loss. MAI represents a new generation of advanced thermal insulation with the performance of silica-based Vacuum Insulation Panels (VIPs) at a low cost. It has been demonstrated to achieve greater than R32/inch in Department of Energy testing, and can be produced at significantly reduced cost when compared to VIPs ($0.10-0.15/ft²/R vs. $0.25/ft²/R). This project is close to completion and estimated to be complete by the end of 2017.

EW-201719, Demonstration and Cost Analysis of an Acoustic Building Infiltration Measurement System by Argonne National Laboratory

• The objective of this project is to demonstrate the cost-benefits for using SonicLQ, an Acoustic Building Infiltration Measurement System (ABIMS), to estimate infiltration rates of military base buildings and locate and size specific leaks. ABIMS uses sound waves to both locate and size leaks in buildings with one measurement which will both speed up building envelope leak detection and location and help prioritize the sealing of the leaks to meet infiltration requirements. This is a new project funded this year (2017) and is estimated to be complete in 2019.

As part of our webinar series to promote the transfer of successful technologies, ESTCP is hosting a webinar on the topic of Building Envelope Technologies. The Principal Investigators from two of the projects above, EW-201719 and EW-201511, will present in detail on their technology. The webinar is scheduled for November 16, 2017 from noon to 1:30 pm ET. To learn more about these technologies, please register for the webinar here.