Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota
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.
Citation Formats
TY - DATA
AB - 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.
AU - Rapport, Ari
A2 - Shaffer, Matthew
A3 - Prahl, Duncan
DB - Open Energy Data Initiative (OEDI)
DP - Open EI | National Renewable Energy Laboratory
DO - 10.25984/2204228
KW - building america
KW - BEopt
KW - WUFI
KW - attic air leakage
KW - attic ventilation
KW - cathedralized attics
KW - closed-cell spray foam insulation
KW - hygrothermal analysis
KW - moisture risk
KW - residential
KW - water vapor flow rate
KW - cold
KW - computational fluid dynamics
KW - multifamily
KW - single family
KW - BuildingAmerica
LA - English
DA - 2016/04/27
PY - 2016
PB - Ibacos Innovation
T1 - Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota
UR - https://doi.org/10.25984/2204228
ER -
Rapport, Ari, et al. Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota. Ibacos Innovation, 27 April, 2016, Open Energy Data Initiative (OEDI). https://doi.org/10.25984/2204228.
Rapport, A., Shaffer, M., & Prahl, D. (2016). Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota. [Data set]. Open Energy Data Initiative (OEDI). Ibacos Innovation. https://doi.org/10.25984/2204228
Rapport, Ari, Matthew Shaffer, and Duncan Prahl. Moisture Risk in Unvented Attics Due to Air Leakage Paths - Minneapolis Minnesota. Ibacos Innovation, April, 27, 2016. Distributed by Open Energy Data Initiative (OEDI). https://doi.org/10.25984/2204228
@misc{OEDI_Dataset_5495,
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.
},
url = {https://data.openei.org/submissions/5495},
year = {2016},
howpublished = {Open Energy Data Initiative (OEDI), Ibacos Innovation, https://doi.org/10.25984/2204228},
note = {Accessed: 2025-05-20},
doi = {10.25984/2204228}
}
https://dx.doi.org/10.25984/2204228
Details
Data from Apr 27, 2016
Last updated Nov 1, 2023
Submitted Apr 27, 2016
Organization
Ibacos Innovation
Contact
Ari Rapport
Authors
Research Areas
Keywords
building america, BEopt, WUFI, attic air leakage, attic ventilation, cathedralized attics, closed-cell spray foam insulation, hygrothermal analysis, moisture risk, residential, water vapor flow rate, cold, computational fluid dynamics, multifamily, single family, BuildingAmericaDOE Project Details
Project Name Building America
Project Number FY14 AOP 1.9.1.19
