- Author
-
Burch, D. M.
|
Thomas, W. C.
- Title
- Analysis of Moisture Accumulation in a Wood-Frame Wall Subjected to Winter Climate.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Department of Energy, Washington, DC
- Report
-
NISTIR 4674,
October 1991,
36 p.
- Distribution
- Available from National Technical Information Service
- Book or Conf
- American Society for Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE). Thermal Performance of the Exterior Envelopes of Buildings V. December 7-10, 1992,
Clearwater Beach, FL,
467-479 p.,
['1991', '1992']
- Keywords
-
moisture
|
capillary transfer
|
moisture control guidelines
|
moisture management in walls
|
moisture performance of walls
|
moisture transfer
|
water vapor diffusion
|
capillary flow
|
siding
- Abstract
- A transient, one-dimensional, finite-difference model is presented that predicts the coupled transfer of heat and moisture in a multilayer wall under nonisothermal conditions. The model can predict moisture transfer in the diffusion through the capillary flow regimes. It has a provision to account for convective moisture transfer by including embedded cavities which may be coupled to indoor and outdoor air. The model is subsequently used to predict the time-varying average mositure content in the sheathing and siding of a wood frame wall as a function of time of year. Results are shown for a mild winter climate (Atlanta, GA), an intermediate winter climate (Boston, MA), and a cold winter climate (Madison, WI). The effect of several construction parameters on the winter moisture accumulation are investigated. The parameters include the interior vapor retarder permeance, sheathing permeance, exterior paint permeance, indoor air leakage, and the amount of insulation.