Comparison between methods of rainwater tank sizing suggested by ABNT NBR 15527:2007 for rainwater harvesting system in a single family home – CARAPICUÍBA - SP

Abstract

The techniques of rainwater harvesting are sustainable solutions that collaborate for the rational use of water, making conservation of water resources for future generations feasible. This paper’s objective is to compare the various methods of rainwater tank sizing suggested in the Brazilian standard NBR 15527:2007 for a rainwater harvesting system in a single family home in the city of Carapicuíba, SP. By means of surveying the final uses of non-potable water in the building, it is possible to estimate the volume of water needed to supply the demand for non-potable water for activities such as car washing, backyard washing, sidewalk washing and irrigation of gardens. It was essential to the study the collection of rainfall data and verification of the rainfall catchment area of the study site. Subsequently to the data collection, the rainwater tank was sized by means of six different methods, and a comparison was made between them, where it was verified that the choice of the ideal method of sizing will be according to the final interests of implantation of a rainwater harvesting system and also according to the region of implantation. In the case studied, the methods that better adhered to the demand were the Australian method and the simulation method with a rainwater tank of volume of 3m³.