Abstract
During the past few years several different computer models have been developed that can predict the hydrothermal behavior of building walls with different degrees of complexity. A new hygrothermal model has been developed that combines the building envelope parts and the indoor climate. The model is capable of predicting the combined transfer of heat and moisture, including liquid and vapor flow and phase changes of moisture in the porous media and CO2 diffusion and convection. In this study, the effects of water vapor diffusion on the hygrothermal performance of walls and CO2 diffusion on indoor air quality are analyzed. Moisture can have several unwanted effects on the durability of building materials, such as rotting, mold growth, corrosion, and deterioration of masonry. The effect of vapor and CO2 diffusion through building walls on the interior climate and wall moisture contents are presented as functions of ventilation rates for a corner bedroom. The model is verified against small-scale experiments in huts exposed to real environmental conditions. These results are then expanded for a full-scale house using the simulation model. Results clearly show the importance of diffusion processes on the indoor climate at low ventilation rates. At high ventilation rates, the effect becomes insignificant and the indoor climate in the rooms approach each other, as would be expected.
Original language | English |
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Pages (from-to) | 908-918 |
Number of pages | 11 |
Journal | ASHRAE Transactions |
Volume | 104 |
Issue number | 2 |
State | Published - 1998 |
Externally published | Yes |
Event | Proceedings of the 1998 ASHRAE Annual Meeting - Toronto, Can Duration: Jun 21 1998 → Jun 24 1998 |