A testing methodology for quantification of wind-driven rain intrusion for building-integrated photovoltaic systems

Abstract Wind-driven rain (WDR) exposure is a crucial impact factor to consider for building envelope components and systems. The roof being a climate screen, shields inner structures from various precipitations preventing most of the water from intruding. Although WDR exposure tests are quite common, there is a lack of studies that explore a quantification of water intrusion during such an experiment. Novel technologies such as e.g. building-integrated photovoltaic (BIPV) systems have been steadily more used as the building envelope components, and majority of BIPV systems are designed for roof integration. Such systems are mainly viewed as electricity generators, consequently, the power output and parameters that affect them are usually in focus when these systems are evaluated, whereas little information is available on the weather protection performance of BIPV systems. To address this gap, a series of experiments were conducted to improve the testing methodology of WDR exposure for BIPV systems where quantification of water intrusion was implemented. As a result, a novel framework is presented, which includes a step-by-step test methodology and a detailed description of the construction of a water collection system. Selected BIPV system for roof integration was tested according to the methodology and collected water amounts were provided. The findings in this study demonstrate that quantification of water intrusion is feasible and provides performance-based information that will help improving the design of BIPV systems as climate screens.