The Research On Indoor Environment And Ventilation Of Urban Residential Buildings In Temperate Climate Zone

As people spend more than 80% of time indoors,thereby indoor environment and natural ventilation are crucial.As one of five climate zones in China,temperate climate zone has special low-latitude and high-altitude geographical features as well as excellent air quality conditions throughout the year,which makes it very suitable for natural ventilation.Study of indoor environment and natural ventilation in residential dwellings in temperate climate zones could be used to explore indoor environment and performance of natural ventilation under ideal outdoor conditions.This article used comprehensive method of questionnaire survey,household measurement and long-term sensor monitoring of indoor environment and natural ventilation in urban residential building of Kunming,Yunnan Province.There are thirty dwellings participating in the household measurement,and thirteen of them participating the long-term monitoring.In the aspect of indoor pollutants measurement,household measurement included indoor formaldehyde,BTX series volatiles organic compounds(VOCs)and other pollutants.Results showed the average formaldehyde concentration in summer exceeded China's national standards.The average benzene concentration of bedrooms in winter exceeded the World Health Organization(WHO)standards.By using long-term monitoring data,it was found that indoor PM2.5 concentration exceeded WHO standard in winter and spring,and the indoor PM2.5 were mainly sourced from indoor.In the aspect of thermal comfort,indoor temperature and humidity in winter are not enough to meet the conditions of thermal comfort.In the aspect of natural ventilation,the length of window-opening time is analyzed.Machine learning models such as the decision tree,support vector machine(SVM)established predictive models of the window-opening behavior,which would be convenient for future research on the window-opening and natural ventilation behavior in the temperate climate zones.As the infiltration rate is lower than both Chinese and ASHRAE standard,only the infiltration is insufficient to meet the health demand.This paper mainly focused on natural ventilation of the bedroom.Night ventilation of the bedroom throughout the year can meet the ventilation requirements.This paper comprehensively studied the indoor environment and natural ventilation of urban dwellings in temperate climate zones,obtained a large number of original sample data.The situation of indoor environment and natural ventilation in temperate climate zones is also analyzed,which can provide reference for residential design in temperate climate zone.