Application of reference-free natural background–oriented schlieren photography for visualizing leakage sites in building walls

Journal Article · Fri Aug 26 00:00:00 EDT 2022 · Building and Environment

DOI:https://doi.org/10.1016/j.buildenv.2022.109529· OSTI ID:1885342

Boudreaux, Philip R. ^[1]; Venkatakrishnan, Singanallur ^[1]; Iffa, Emishaw ^[1]; Hun, Diana E. ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Air leakage in buildings can cause health and comfort concerns for occupants and can contribute to mold growth on building materials, or in extreme conditions, rot of building materials. Unwanted air leakage through the building envelope also contributes to approximately 4 quadrillion Btu (1172 TWh) of energy consumption per year in the building sector in the United States. Locating and sealing leakage sites can improve the energy efficiency, comfort, air quality, and moisture durability of the building stock. Typical methods of finding leakage sites, such as infrared imaging and smoke tracing, rely on concurrent blower door operation, which can also measure the total leakage rate of the building. Smoke tracing can be disruptive to occupants, and infrared imaging and smoke tracing cannot measure the contribution of individual leaks to prioritize sealing efforts. Here, an optical fluid flow imaging technique, reference-free natural background–oriented schlieren imaging, was adapted to visualize air exfiltration. This is the first step in developing a method to noninvasively locate and measure exfiltration or infiltration sites so that sealing efforts can be prioritized. Experimental results of this technique are presented, demonstrating the method's applicability to visualizing exfiltration through three common building claddings in an outdoor environment. Key variables impacting the performance of this technique when applied to building leakage are also discussed.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Building Technologies Office
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1885342
• Journal Information: Building and Environment, Journal Name: Building and Environment Vol. 223; ISSN 0360-1323
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

29 ENERGY PLANNING, POLICY, AND ECONOMY
Schlieren
air leakage
building envelope
exfiltration
optical flow