| Description |
1 online resource (ix, 110 pages) : illustrations (some color) |
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text txt rdacontent |
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computer c rdamedia |
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online resource cr rdacarrier |
| Note |
"Prepared for the National Renewable Energy Laboratory on behalf of the U.S. Department of Energy's Building America Program, Office of Energy Efficiency and Renewable Energy." |
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"November 2013." |
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"NREL technical monitor: Cheryn Metzger." |
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"DOE/GO-102013-4266"--Page [120]. |
| Bibliography |
Includes bibliographical references (pages 77-79). |
| Summary |
The following report explains the moisture-related concerns for High R-value wall assemblies and discusses past Building America research work that informs this study. Hygrothermal simulations were prepared for several common approaches to High R-value wall construction in six cities (Houston, Atlanta, Seattle, St. Louis, Chicago, and International Falls) representing a range of climate zones (2, 3, 4C, 4, 5A, and 7, respectively). The simulations are informed by experience gained from past research in this area and validated by field measurement and forensic experience. The modeling program was developed to assess the moisture durability of the wall assemblies based on three primary sources of moisture: construction moisture, air leakage condensation, and bulk water leakage. The peak annual moisture content of the wood based exterior sheathing was used to comparatively analyze the response to the moisture loads for each of the walls in each given city. Walls which experienced sheathing moisture contents between 20% and 28% were identified as risky, whereas those exceeding 28% were identified as very high risk. All of the wall assemblies perform well under idealized conditions. However, only the walls with exterior insulation, or cavity insulation which provides a hygrothermal function similar to exterior insulation, perform adequately when exposed to moisture loads. Walls with only cavity insulation are particularly susceptible to air leakage condensation. None of the walls performed well when a precipitation based bulk water leak was introduced to the backside of the sheathing, emphasizing the importance of proper flashing details. |
| Funding |
Prepared under KNDJ-0-40337-04 |
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NREL DE-AC36-08GO28308 |
| Note |
Title from title screen (viewed on May 1, 2014). |
| Subject |
Dampness in buildings -- Computer simulation.
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Exterior walls -- Thermal properties -- Computer simulation.
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Walls -- Moisture.
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Dwellings -- Insulation.
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| Genre/Form |
Online resources.
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Electronic books.
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Electronic government information.
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| Added Author |
Schumacher, C., author.
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Lukachko, A., author.
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United States. Department of Energy. Building Technologies Office, issuing body.
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National Renewable Energy Laboratory (U.S.), sponsoring body.
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Building America (Program : U.S.), sponsoring body.
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| Gpo Item No. |
0429-A-90 (online) |
| Sudoc No. |
E 1.177:DOE/GO-102013-4266 |
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