Rational sizing of greywater systems
Greywater systems are becoming more and more important as an alternative to main water due to the decreasing water resources. It is known that a third of main water demand can be substituted by the reuse of greywater. Most of actual greywater systems can reach this percentage of saving depending on the greywater sources available and the expected use. It has been determined that the more the water source matches to a specific demand, the more the system is efficient and worthy through its life expectancy considering both quantity and quality aspect of the water. It means that the efficiency of such systems is linked to a good sizing of greywater storage. But it has also been determined that the efficiency of a system depends on usage patterns and behaviour of people concerning water appliances, which lead to a randomness use of the water. This paper uses previous studies, works and papers to identify gaps on sizing of greywater systems, proposes a new model based on the flow rate rather than the volume in the previous studies in order to match the demand and the supply in a more realistic and reliable way. This report explains how the flow rate system has been developed on Excel, presents the results coming from this model and compares it to previous studies. The conclusion includes also recommendations for future changes in the program in order to improve it.