A review of wind-driven rain research in building science

Wind-driven rain (WDR) or driving rain is rain that is given a horizontal velocity component by the wind. WDR research is of importance in a number of research areas including earth sciences, meteorology and building science. Research methods and results are exchangeable between these domains but no exchanges could yet be noted. This paper presents the state-of-the-art of WDR research in building science. WDR is the most important moisture source affecting the performance of building facades. Hygrothermal and durability analysis of facades requires the quantification of the WDR loads. Research efforts can be classified according to the quantification methods used. Three categories are distinguished: (1) experimental methods, (2) semi-empirical methods and (3) numerical methods. The principles of each method are described and the state-of-the-art is outlined. It has been the intent of the present paper to bring together the reports, papers and books-published and unpublished-dealing with WDR research in building science to provide a database of information for researchers interested in and/or working in WDR research, independent of their field of expertise.