Wind-driven rain tightness of building-integrated photovoltaics panels

The exposure to wind-driven rain (WDR) is a key factor impacting the performance and the durability of the building envelope. Building-integrated photovoltaic (BIPV) panels are increasingly used as roofing and façade materials, but little information is available on their weather protection performance. Although WDR exposure has been qualitatively investigated in laboratories, only few studies have directly quantified the water intrusion through BIPV. This article presents the results from a WDR laboratory test of a BIPV product, where water intrusion was both qualitatively and quantitatively investigated. Furthermore, as roof integration is the primary function of the studied BIPV panels, the results from the same test performed on another traditional roofing material, i.e., concrete tiles, are described and discussed. The test results showed that the BIPV panels performed better as façade cladding than as roofing material, since no quantifiable water leakages were detected at 90° inclination. At 15° and 30° inclinations, the total water leakages through the BIPV system were around 90% lower than those of the concrete tile roofing. This article’s findings demonstrate that the quantification of water intrusion through BIPV panels is feasible and can provide significant information for further developing and improving the design of BIPV systems as climate screens.