Fluctuation Behaviors of Air Pressure in a High-Rise Building Drainage System

Abstract

Air pressure fluctuation behaviors in a high-rise building drainage system (HBDS) are presented by probability density functions and statistical analysis of measured data in the drainage stack in a real-life eighteen-floor building, the Li Ka-Shing (LKS), at PolyU of Hong Kong. Three observation points, at the mezzanine (M), 6th, and 12th floors, are arranged to record the air pressure in the primary building stack. The measured data are stored in a personal computer with a sampling period of 1 s. Statistical analysis revealed that there is an evident floor dependence of the air pressure in the real-life HBDS. The flatness factor of the pressure fluctuation increases with floor number, whereas the skewness factor has a reversed variation tendency; it decreases from a positive value in the M floor to negative values at higher floors. Probability density functions show the pressure fluctuation behaviors are far from normal distributions.