B014 Domestic flush demand

Influence of domestic occupant load on flushing water consumption

Brief:

Design of building drainage systems requires a reasonable estimation of flushing water consumptions. Domestic WC would consume 30-40% of the total water supply in a domestic building, however, little is currently known concerning the flushing water consumption due to occupant load patterns in cities having a high population density, e.g., Hong Kong. This paper highlights the occupant load pattern in the residential building has significant influence on the domestic flushing water consumption. In particular, a simple stochastic model is proposed with the parameters determined for typical residential buildings in Hong Kong; the model parameters including the installed cistern capacity of water closets, variations of occupants’ demands, occupant load and its diurnal variations are determined from recent studies on domestic WC usage patterns. The results show that occupant load and its variations have significant influence on the flushing water consumptions. The variations of the domestic flushing water consumption due to various occupant load conditions in typical residential buildings in Hong Kong are illustrated with the proposed model.

Further information:

Wong LT, Mui KW, 2004. Influence of domestic occupant load on flushing water consumption, Joint Symposium 2004: Servicing Dense Built Environment, CIBSE, Kowloon Shangri-La Hotel, 16 November, Hong Kong, pp. 89-97.