(Reference ) Evaluation and Design of Rain water Re-circulation
Rain water recycle system includes rain collection, treatment, storage and supply of water facilities. At the preliminary stage of recycle rain water, one must take into account and evaluate the rain water collection and usage frequency. Then, the area of water surface and the capacity of the storage facility determines the earlier two factors. The calculation of the rain water collected is simple . It is the depth of rain water times the area of rain water .
Normally, taken from the meteorological report, evaluation of rain fall can be divided into sporadic , daily , monthly , and yearly rain fall. Using of yearly rain fall record and consumption frequency could be used for preliminary rain water recycle consulting purpose. Any wide variation will cause hard decision in the size of rain water storage system. Normally, daily record of rain fall is taken to be the key for evaluation uses.
Calculation of frequency in rain water usage and accumulation
depend on the relationship among the four factors of the rain water storage tank. These four factors include the inflow portion of the volume of rain water, supplement supply of tap water , outflow portion of the consumption water, and the overflow portion of the water. This can be shown with the diagram .
For calculation purposes, one needs to confirm the location of the rain water usage and yearly assessment . Then, decide the area surface of the rain water size, and frequency usage of the water as mentioned earlier. Refer to the figure 4 below which shows the flow chart that carry out the evaluation .