Abstract
The experimental rainwater recycling system has been constructed and we have researched its performance. In this system, purified water is supplied into the rainwater tank when the volume of stored rainwater for miscellaneous use is insufficient. The consumption of the purified water used for miscellaneous use is varied with the way of purified water supply. The way that consumes very little purified water for miscellaneous use is; 1)supply of the purified water into the tank starts when the volume of stored rainwater is less than the volume of water for miscellaneous use in two days, 2)volume of the supplied water is equal to the volume of water for miscellaneous use in a day. If the rainwater recycling system is introduced every office building which number of the floors is less than 10, the volume of purified water for miscellaneous use decreases approximately 30%.
