- Author
-
Thomas, W. C.
|
Burch, D. M.
- Title
- Experimental Validation of a Mathematical Model for Predicting Water Vapor Sorption at Interior Building Surfaces.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Journal
-
ASHRAE Transactions,
Vol. 96,
No. Part 1,
487-496,
1990
- Report
-
Paper 3357,
- Book or Conf
- American Society of Heating, Refrigerating, and Air Conditioning Engineers, Inc. (ASHRAE). Desiccant Cooling and Dehumidification. 1992,
115-164 p.,
['1990', '1992']
- Keywords
-
mathematical models
|
moisture sorption
|
building surfaces
|
validation
|
equations
|
implicit finite-difference method
|
surface coatings
|
gypsum board
|
paints
|
moisture content
|
heat transfer
|
desorption experiments
|
wood
|
ventilation
- Abstract
- A mathematical model for predicting moisture sorption rates at building surfaces is presented. The governing heat and moisture transfer equations are solved by an implicit finite-difference method. The effects of surface coatings are included in the formulation. Laboratory experiments were conducted to verify the model. Disk-shaped specimens of unpainted gypsum board, gypsum board painted with a latex paint system, and unpainted white pine were used. Sorption isotherms and diffusion coefficients for these materials were independently measured. The specimens were initally conditioned to a uniform mositure content and then moved to an environment with a lower relative humidity. The moisture transfer rates at the surfaces of the specimens were determined as a funciton of time and compared to predicitons by the mathematical model. The validated mathematical model was used to estimate sorption rates at interior surfaces of a building during a summer diurnal schedule with day space cooling and night ventilaiton. The effect on the space-cooling load is discussed.