Abstract
For the sustainable society, sparing tap water and energy in urban life is one of keys in solving the problem of resource and environment. In general, the rain water storage facility has been projeted to use rain water for non-potable water instead of city water. But the rain water should be used for many other aspects. The one is to use for cooling water. It is essential to evaluate the ability of rain water used for cooling water as an unused energy. In this study, the rain water storage facility of the R system in which the rain water is used for saving city water and cooling a refrigerating unit has been analysed to evaluate the performance in saving of city water and energy. The R system has an artificial set of open channel and pond serving as a favorable waterscape. The rain water used for cooling water is cooled and regenerated by the artificial set in the R system. A simulation program has been developed to calculate the amount of water and electricity saved by using rain water for grey water and cooling water. Several numerical runs were conducted by the simulation program and the water and energy saving properties of the R system were evaluated.
