Demand Analysis for Residential Water Supply Systems in Hong Kong

Accurate estimates of probable maximum simultaneous demand are essential for sizing the water supply plants and piping systems of high rise residential buildings cost-effectively and eco-efficiently. This paper surveyed the water usage patterns through face-to-face interviews and simple on site measurements from some typical high-rise residential buildings in Hong Kong and investigated the probable maximum demands of domestic appliances in terms of fixture units determined at an allowable failure rate of 1% of the peak hourly demands. The fixture units of a WC, a washbasin, a shower, a kitchen sink and a 5 L washing machine were quantified and compared with the current design values. The results showed that the latter must be reviewed. This study hence provides a useful source of reference for the optimisation of water supply and piping systems in high-rise residential buildings.