Validation of Design Methodology for Rainwater Harvesting for Tropical Climates

Promotion of sustainable development in the building sector with reduced embodied energy and life cycle costs has become a primary need for facing the emerging threats of global warming and depleting energy sources. In this context, the minimization of the dependence on reticulated water supply is of crucial importance due to the high level of operational energy and the cost associated with the reticulated water supply. For this purpose, rainwater harvesting (RWH) can offer an ideal solution where the harvested water can be easily used for flushing of toilets and gardening. Though design curves and parameters are available for design of the rainwater tanks for a significant water saving efficiency (WSE) in temperate climate regions, the validity and the applicability of these curves and parameters for tropical climate regions such as Sri Lanka, where rainfall patterns vary significantly across geographical and climatic boundaries, is still limited. It is also important to utilize a practical solution to develop multiple data, using short-term rainfall data, in order to compensate for the lack of available data for many geographical regions. In this research, a practical methodology was employed using short-term rainfall data and an experimental set up to validate design curves for WSE, obtained in temperate climate regions, to predict the WSE for tropical climate regions.