Air Pressure Fluctuations of Drainage Stacks at a High-rise Office Building

Liao, Wan-Ju; Mui, Kwok Wai; Cheng, CL; Wong, Ling Tim; He, K.C.

doi:10.1177/1420326x11409602

Cited by 19 publications

(24 citation statements)

References 11 publications

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“…[13][14][15][16][17] Otsuka provided five predictive methods based on ventilation systems and gradually concluded the predictive models of the single-stack drainage system, suction valve equipped drainage system and special ventilation system. [12][13][14][15][17][18][19][20][21] In 2011, Liao et al 22 studied the air pressure fluctuation of the drainage system in a highrise office building. This study illustrated the air pressure changes along with the pipe height under a transient flow condition, and it also tested the air pressure fluctuation frequency, the maximum and average pressure, and their standard deviations.…”

Section: Introductionmentioning

confidence: 99%

Influence of installation of S-shaped pipe offset on the water flow capacity of double stack drainage system in a high-rise building

Guan

Fang

Yuan

et al. 2019

Building Services Engineering Research and Technology

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In high-rise and ultra-high-rise residential buildings, the drainage systems usually adopt the S-shaped offset pipe joint to avoid collisions of pipelines with beams and columns. However, the flow direction changes at the offset point would significantly affect the drainage capacity of the systems. To better understand the influence of pipe offset joints on the drainage capacity, three different building drainage systems namely YZW 1, YZW 2, and YZW 3 systems, were built up and investigated. YZW 1 system is a standard double-stack drainage system with anti-reflux H-tube joints. YZW 2 and YZW 3 systems were developed from YZW 1 by adding S-shape offset pipe joints on the 4th floor. An extra anti-reflux H-tube joint added 1 m above the offset joint as a measure for improving the drainage capacity differentiates YZW 3 system from YZW 2 system. The pressure fluctuation and water seal losses were adopted as experimental parameters to determine the maximum discharge capacity according to Standard for Capacity Test of Vertical Pipe of the Domestic Residential Drainage System. The experimental results show that the discharge capacity limitation of the drainage system with the offset joint is 6.5 L/s, which is much smaller than 11.0 L/s of the system without the offset joint. In the experiments with the offset joint, the pressure fluctuated fiercely at the position where flow direction changed and caused severe water seal losses of the floor drain and P-shaped trap. An anti-reflux H-tube joint above the original offset joint was observed to relieve the pressure fluctuation as an improvement and the drainage capacity was improved to some extent. The relationships among the maximum discharge rate, pressure fluctuation transients, and water seal losses were discussed. Lastly, a nondimensional analysis was adopted to understand the relationship between water seal losses and pressure limit values under different discharge rates for current test facilities. Practical application: A method has been tested and approved to effectively improve the discharge ability of a building drainage system that includes offset. The application of S-shape-offsets in high-rise building drainage systems can relieve the discharge congestion typically caused by standard pipe offset arrangements.

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Section: Introductionmentioning

confidence: 99%

Influence of installation of S-shaped pipe offset on the water flow capacity of double stack drainage system in a high-rise building

Guan

Fang

Yuan

et al. 2019

Building Services Engineering Research and Technology

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“…17 The transmission of virus in sewage containing faecal matters transported in drainpipe in multi-storey high-rise buildings is a possibility. 18 The indirect long-range route of transmission (droplet nuclei transmission or aerosol transmission) is a possibility and could occur but this is currently Exhaled flow dispersion between occupants in close proximity. 14 unconfirmed and needs to be proven.…”

Section: Transmission Of Covid 19mentioning

confidence: 99%

The 2019-nCoV epidemic control strategies and future challenges of building healthy smart cities

Xin

et al. 2020

Indoor and Built Environment

111

114

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The 2019 Novel Wuhan Coronavirus (2019-nCoV) epidemic (namely COVID 19) was first reported and confirmed on 31 December 2019, in Wuhan, Hubei Province, China, which is one of China's largest cities and a major domestic transport hub (located in the central part of China, as shown in Figure 1). 1 The epidemic is attracting worldwide concern due to its rapid spread and transmission rate between humans. On 30 January 2020, the International Health Regulations, Emergency Committee of the World Health Organization (WHO) declared the outbreak-a 'public health emergency of international concern'. 2 On 8 February 2020 (24:00 GMT þ 8), there were 37,198 confirmed infections in China (including 811 deaths with a death ratio of 2.1%; and 6188 patients were confirmed in serious condition and 28,942 suspected cases). 3 The COVID 19 infections were also reported in 26 other countries on

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“…In these studies, the pressure transients have been examined but not water seal loss characteristics or the influence of ventilation. 20…”

Section: Introductionmentioning

confidence: 99%

Influence of the vent pipe diameter on the discharge capacity of a circuit vent building drainage system

Guan

Fang

Tao

et al. 2019

Building Services Engineering Research and Technology

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Experiments on different vent pipe diameters (nominal diameters of 100, 75 and 50 mm; DN100, DN75 and DN50, respectively) in a full-scale circuit vent building drainage system were conducted in a 60 -m high structure, and the wastewater discharge capacities as a function of vent pipe diameter were measured. Critical pipe pressures, water seal losses of sanitary fixtures and air flow rates were measured. The ultimate pressure values in pipes on lower floors were larger than those in pipes on higher floors using DN100 and DN75, which was opposite to the results with DN50. A positive correlation between the ultimate pressure values and floor heights, as well as between ultimate pressure values and water seal losses, was found for DN100 and DN75. The maximum discharge flow of the three systems using DN100, DN75 and DN50 vent pipes was 17.0 L/s, 14.0 L/s and 7.5 L/s, respectively. Nevertheless, in China, the maximum wastewater discharge capacity in a circuit vent system adopting a DN100 vent pipe connected to a DN100 drainage stack in tall residential buildings is 11.5 L/s according to the Code for Design of Building Water Supply and Drainage. Thus, the vent pipe diameter DN75 can fully meet the design requirements of drainage systems for high rise buildings in China. The engineering cost associated with material expenses for building drainage systems can be minimised by optimising the size of vent pipe based on required capacity rather than using a single size universally. Practical application: The engineering cost associated with material expenses for building drainage systems can be minimised by optimising the size of vent pipe based on required capacity rather than using a single size universally.

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Air Pressure Fluctuations of Drainage Stacks at a High-rise Office Building

Cited by 19 publications

References 11 publications

Influence of installation of S-shaped pipe offset on the water flow capacity of double stack drainage system in a high-rise building

Influence of installation of S-shaped pipe offset on the water flow capacity of double stack drainage system in a high-rise building

The 2019-nCoV epidemic control strategies and future challenges of building healthy smart cities

Influence of the vent pipe diameter on the discharge capacity of a circuit vent building drainage system

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