| Abstract | For an efficient moisture performance analysis of walls, the selection of wall orientation for undertaking the hygrothermal simulations plays an important role. The wall orientation receiving the highest amount of annual wind-driven rain (WDR) and the one receiving the least annual solar radiation is that which is recommended in ASHRAE 160. There are different methods to select this orientation, called “default orientation” and the objective of this study is to answer two questions: (i) Are the different methods consistent with each other in terms of default orientation selection? (ii) Is the default orientation, as suggested by any method, identical to the orientation that actually (using simulation outputs) leads to the worst moisture response? Four methods for selecting the default orientation were investigated: ASHRAE, ISO, Climatic Index (CI), and product of rain and wind speed (R*v). Simulations were carried out under historical climate of different Canadian cities for two different wood-frame 2 × 6 inch wall systems that differ by their claddings: brick veneer and stucco. A moisture source of 1% of WDR was also assumed to be present on the exterior side of the sheathing membrane. Four cardinal orientations (North, East, South, and West) and the default orientation, as suggested by a given method, were evaluated in this study. Results showed that the ASHRAE and ISO suggest the same default orientation for most of the cases and this orientation also results in the worst performance on the basis of actual simulation results. |
|---|
