Quantification of Wind-Driven Rain Intrusion in Building-Integrated Photovoltaic Systems

Abstract

Wind-driven rain (WDR) impact is a serious exposure that affects performance of the building envelope components and systems. This study presents results from a laboratory investigation of a testing methodology of WDR intrusion in building-integrated photovoltaic (BIPV) systems. The major aspect proposed in this work is a quantification of water intrusion through BIPV systems. For that matter, a water collection system was designed and tested. When water intrusion is quantified, it may enable categorisation and comparison of various BIPV systems according to their watertightness level. This methodology was applied to three BIPV systems designed for roof integration. The methodology can also be modified and used for various building envelope systems, including traditional roof and facade systems without PV or BIPV systems. As the methodology was developed with climate conditions in northern Europe in mind, WDR exposure of extreme levels was applied. Wind speed ranges from 12.9 m/s (strong breeze) to 35.3 m/s (hurricane) were used. When it comes to newly developed and not well-studied building envelope systems, such as various BIPV systems, they should be subjected to a more extensive investigation. The proposed testing methodology could become an extension of the standard investigations of BIPV systems carried out at accredited laboratories.