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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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98 records · Page 6

Development of novel techniques for non-invasive air leakage and moisture detection in building envelopes

Unwanted air leakage and moisture in building envelopes can cause high energy consumption, detrimental indoor air quality, poor occupant comfort, and reduction in building material durability. High moisture can cause rot and mold, leading to costly and time-consuming repairs that add to the carbon burden of the building envelope. Novel detection techniques for locating and measuring air leakage flow and areas of high moisture in building envelopes will be presented. The techniques are easy, fast, and non-destructive which can enable quick building envelope assessment, foster retrofits, and lead to energy savings and carbon emission reduction.

Boudreaux, Philip [ORNL] (ORCID:0000000229564665)↗

Coastal Forest Seawater Exposure Increases Stem Methane Concentration

Methane (CH 4 ) exchange between trees and the atmosphere has recently emerged as an important, but poorly quantified process regulating global climate. The sources (soil and/or tree) and mechanisms driving the increase of CH 4 in trees and degassing to the atmosphere are inadequately understood, particularly for coastal forests facing increased exposure to seawater. Here, we investigated the eco-physiological relationship between tree stem wood density, soil and stem oxygen saturation (an indicator of redox state), soil and stem CH 4 concentrations, soil and stem carbon dioxide (CO 2 ) concentrations, and soil salinity in five forests along the United States coastline. We aim to evaluate the mechanisms underlying greenhouse gas (GHG) increase in trees and the influence of seawater exposure on stem CH 4 accumulation. Seawater exposure corresponded with decreased tree survival and increased tree stem methane. Tree stem wood density was significantly correlated with increased stem CH4 in seawater exposed gymnosperms, indicating that dying gymnosperm trees may accumulate higher levels of CH 4 in association with seawater flooding. Further, we found that significant differences in seawater exposed and unexposed gymnosperm tree populations are associated with increased soil and stem CH 4 and CO 2 , indicating that seawater exposure significantly impacts soil and stem greenhouse gas abundance. Our results provide new insight into the potential mechanisms driving tree CH 4 accumulation within gymnosperm coastal forests.

54 ENVIRONMENTAL SCIENCES↗

Monitoring of Unvented Roofs with Fibrous Insulation, Diffusion Vents, and Interior Vapor Control in a Cold Climate

This research involved construction of a conditioned test hut in a cold climate (Climate Zone 5A) with multiple side-by-side instrumented roof rafter bays. This work examined seven experimental unvented roofs and one code-compliant control hybrid ccSPF-cellulose roof over three winters and following summers. Examined variables included insulation material (fiberglass and cellulose), the presence or absence of a ridge diffusion vent (vapor-open material at the roof ridge to promote drying), the effect of various interior vapor control membranes (fixed and variable permeance), the effect of interior relative humidity, and the effect of interstitial airflow (from the interior into the cavity). This experiment was run over three winters, changing variables of interior conditions, roof configurations/materials, and the addition of intentional air leakage.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗