Numerical study of wind-driven rain distribution on low-rise buildings with different roof styles

The quantity and distribution of wind-driven rain on building envelopes have considerable effect on the hygrothermal performance and the material durability of building facades. A better understanding of the mechanism of wind-driven rain and its interaction with the building is of important to the building maintenance design. In this paper, the wind-driven rain distribution on a low-rise building with different roof styles is studied using the numerical simulation technique. Three roof styles, including gable roof with overhangs, gable roof without overhang and flat roof without overhang are considered. The obtained results indicate that the wind-driven rain on flat-roofed buildings is more concentrated at the top area of the windward wall than that on gable-roofed buildings, especially in low-wind velocity situations, and the roof overhangs of the building have a shielding effect on the reaching rain drops which decreases the amount of wind-driven rain on the top area of the wall.