Air pressure variations at drainage stacks of high-rise residential buildings

Purpose - The purpose of this paper is to examine the air pressure variations in an in-use drainage stack of high-rise residential buildings with the probable influence of occupant loads. Design/methodology/approach - The air pressure variations in a drainage stack of a typical in-use high-rise residential building in Hong Kong were correlated to the number of water closet (WC) flushes of the building. In particular, measured diurnal WC flushing patterns of the residential buildings were used to correlate the diurnal pressure variations measured at 16 m above the stack base in a 115 m high, 150 mm diameter fully vented drainage stack of a typical high-rise residential building of Hong Kong. Findings - The occurrence of the maximum air pressure in the stack could be correlated with the expected hourly WC flushes of the high-rise residential buildings with mathematical demonstrations. Research limitations/implications - There may be high speed transients in the stack (>1 hertz) which was not measured. Originality/value - The result would be a useful source of reference for the development of control strategies against probable appliance seal loss in high-rise residential buildings.