Wood frame wails typically need a vapour barrier at the warm side to avoid interstitial condensation due to vapour diffusion and air leakages from the interior. A more vapour open material than the traditional vapour ...Wood frame wails typically need a vapour barrier at the warm side to avoid interstitial condensation due to vapour diffusion and air leakages from the interior. A more vapour open material than the traditional vapour barriers, here calted vapour retarder, could allow condensed moisture, buiLt-in-moisture or moisture from minor leakages to dry to the interior in addition to the outward drying. The application of permeable vapour retarders in wood frame wails have been investigated in this study by the use of a hygrothermat simulation tool. A traditional wood frame wail usually has good drying possibilities to the exterior. If a vapour retarder should have an effect on the total drying, it must not be too vapour tight. The purpose of this study was to find some threshold value for the maximum vapour resistance of a vapour retarder--when a requirement is that it should have a relatively large effect of the total drying of the wail. The increased risk for condensation as the vapour resistance decreases has however not been investigated in this study. In general it was found that permeable vapour barriers have retatively littte effect on the total drying of ordinary wood frame waits in a Nordic ctimate.展开更多
文摘Wood frame wails typically need a vapour barrier at the warm side to avoid interstitial condensation due to vapour diffusion and air leakages from the interior. A more vapour open material than the traditional vapour barriers, here calted vapour retarder, could allow condensed moisture, buiLt-in-moisture or moisture from minor leakages to dry to the interior in addition to the outward drying. The application of permeable vapour retarders in wood frame wails have been investigated in this study by the use of a hygrothermat simulation tool. A traditional wood frame wail usually has good drying possibilities to the exterior. If a vapour retarder should have an effect on the total drying, it must not be too vapour tight. The purpose of this study was to find some threshold value for the maximum vapour resistance of a vapour retarder--when a requirement is that it should have a relatively large effect of the total drying of the wail. The increased risk for condensation as the vapour resistance decreases has however not been investigated in this study. In general it was found that permeable vapour barriers have retatively littte effect on the total drying of ordinary wood frame waits in a Nordic ctimate.
