U.S. Department of EnergyOffice of Scientific and Technical Information
Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota
Abstract
IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used "Warme und Feuchte instationar Pro two-dimensional modeling" to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.
- Authors:
-
- Ibacos Innovation
- Publication Date:
- Other Number(s):
- 5495
- DOE Contract Number:
- ;
- Research Org.:
- DOE Open Energy Data Initiative (OEDI); Ibacos Innovation
- Sponsoring Org.:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Building Technologies Office (EE-5B)
- Collaborations:
- Ibacos Innovation
- Subject:
- Array; attic air leakage; attic ventilation; BEopt; building america; BuildingAmerica; cathedralized attics; closed-cell spray foam insulation; cold; computational fluid dynamics; hygrothermal analysis; moisture risk; multifamily; residential; single family; water vapor flow rate; WUFI
- OSTI Identifier:
- 2204228
- DOI:
- https://doi.org/10.25984/2204228
Citation Formats
Rapport, Ari, Shaffer, Matthew, and Prahl, Duncan. Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota. United States: N. p., 2016.
Web. doi:10.25984/2204228.
Rapport, Ari, Shaffer, Matthew, & Prahl, Duncan. Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota. United States. doi:https://doi.org/10.25984/2204228
Rapport, Ari, Shaffer, Matthew, and Prahl, Duncan. 2016.
"Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota". United States. doi:https://doi.org/10.25984/2204228. https://www.osti.gov/servlets/purl/2204228. Pub date:Tue Apr 26 20:00:00 EDT 2016
@article{osti_2204228,
title = {Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota},
author = {Rapport, Ari and Shaffer, Matthew and Prahl, Duncan},
abstractNote = {IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used "Warme und Feuchte instationar Pro two-dimensional modeling" to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.},
doi = {10.25984/2204228},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2016},
month = {4}
}