Driving rain on building envelopes - I. Numerical estimation and full-scale experimental verification

An accurate method for the quantification of real-life driving rain loads on building envelopes from generally available climatic data such as wind speed, wind direction and horizontal rainfall intensity serves various purposes, from the development of design guidelines for building envelopes to the incorporation of driving rain loads as a boundary condition in Heat-Air-Moisture (HAM) transfer analysis models. In this paper, an existing numerical technique for driving rain simulation is incorporated into a practical numerical method to estimate driving rain loads on building envelopes based on the building geometry and the climatic data at the building site. This numerical method is applied for several sequences of spells around a low-rise test building and the results are experimentally verified. It is shown that the numerical method can accurately estimate the spatial and temporal distribution of driving rain loads on building envelopes.