Gutter design and selection for roof rainwater catchment systems

Water, while being critical for the survival of all of humanity, is not readily available to everyone. Within much of the developing world, water delivery systems are sub-par, leaving many homes without accessible and sustainable water resources. To address this issue, the use of rainwater harvesting systems is common. However, many extant systems are flawed in design, efficiency or sustainability. This paper investigates the impact of gutter cross-section on the performance and efficiency of rain water harvesting from roof catchments. Multiple gutter systems, with varying cross-sectional profiles, including a novel wrap-gutter design, were built and tested experimentally using a rainwater simulator. Experimental data, together with theoretical analyses, were used to rate gutter performance in terms of water lost though overflow, rate of water drainage, amount of standing water remaining in the gutter, amount of water loss via overshoot and the total amount of rain caught by the gutters. It was found that a wrap design, not normally highlighted in the literature, had the most consistent performance, regardless of rainfall intensity. Analyses regarding context-appropriate designs along with broader economic impacts of RWH systems are discussed.