Development and Testing of a Tall Building Façade System to Collect Rainwater

The key objective of this research was to devise and test a vertical rainwater harvesting system and demonstrate that the rainwater could be collected off building envelopes in sufficient quantities, and then cycled into the buildings’ water systems. While tall building envelopes have traditionally been designed to prevent water infiltration, this study proposes a building envelope system to allow for “controlled water leakage”, transforming into a channel to catch desired rainwater, as well as a barrier to unwanted water infiltration. Weather data were collected for six major cities around the globe experiencing a water crisis, and in which the tall building is the principal building type in the central districts, to determine the optimum building orientation based on normal and average amounts of rain per event. Next, buildings of varying heights were digitally modeled, simulating rain events for each city and the resulting rain volumes. Finally, water-droplet size, adherence, cohesion, filming and streaming of rainwater on building façade were studied, using rainwater performance simulation.