Factors influencing the airflow rate of kitchens in cooking exhaust shaft system of high-rise residential buildings

Abstract

Insufficient shaft cross-sectional area of cooking exhaust shaft system in high-rise buildings influences the ventilation capacity of range hoods in kitchens, which cause damage to human health or increase the energy consumption of the building. There are numerous factors that affect ventilation capacity of the exhaust system, such as exhaust shaft cross section, range hood performance, operating rates and distribution of range hoods. The purpose of this research is to conduct a quantitative study on the effects of these parameters on the airflow rate of kitchens. A theoretical model of the cooking exhaust shaft system was established according to the Fluid Network Theory, it was further validated by a full-scale model experiment and used to calculate the airflow rate of kitchens for a 33-storey residential building. The results show that when the exhaust shaft cross section is designed to be 500 mm × 400 mm according to standard, regardless of the performance of the range hood, the airflow rate of kitchens of some users will be either insufficient or excessive, and cannot meet 300~500 m3/h required by Chinese standards. But when the shaft cross section is 750 mm × 600 mm and the standard range hoods are used, the airflow rate of kitchens can reach 300~500 m3/h at any operating rate. The established model can be applied in other countries to study the ventilation effect of the similar cooking exhaust shaft system in residential or other buildings. The research results can be useful for improving the design of the cooking exhaust shaft system in residential buildings.