This study aims to evaluate the potential for potable water savings by modelling the hypothetical installation of a system that combines rainwater and greywater in a house. The system consists of using rainwater to wash clothes and then reusing the effluent to flush toilets. The potential for potable water savings and the tank capacity for rainwater storage were estimated using the computer programme Netuno. A financial analysis was performed. For a rainwater tank capacity equal to 5000 litres, it was possible to obtain 51.6% potable water savings. The payback period was estimated as five years and three months. The system combining rainwater and greywater is a good alternative to save potable water because there was a significant reduction in potable water consumption and low payback period. The high potable savings and low payback period found in this work may contribute to the acceptability of these technologies and practices.

这项研究旨在通过对假设将房屋中的雨水和中水混合的系统进行模拟安装来评估饮用水节约的潜力。该系统包括使用雨水洗衣服，然后再利用废水冲洗厕所。使用计算机程序Netuno估算了可节水的潜力和用于雨水存储的水箱容量。进行了财务分析。对于等于5000升的雨水箱容量，可以节省51.6％的饮用水。投资回收期估计为五年零三个月。雨水和中水相结合的系统是节省饮用水的一个很好的选择，因为它大大减少了饮用水的消耗，并且回收期很短。这项工作中发现的大量可节省的储蓄和较低的投资回收期可能有助于提高这些技术和实践的可接受性。