Air Pressure Fluctuation Behaviors in a High-rise Building Drainage System

摘要

Air pressure inside the drainage stack is an indicator for the safety retention of water seal.While the excess air pressure destroys water seal of traps and water closets, smell emission from the drainage system will occur and cause health problem.In view of drainage safety, air pressure can be measured for assessment of drainage system in a building.After the SARS outbreak, there are intensive reviews with this respect.A setup has been established to demonstrate how it is assessed.Air pressure fluctuation behaviors in a highrise building's drainage system (HBDS) is presented by probability density functions (PDF) 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 second(s).Statistical analysis reveals that there is an evident floor dependence of the air pressure in the real-life HBDS.