The Effect Of Opening Window On The Indoor Environment In The Naturally Ventilated Dormitory In A University Of Northern China In Winter

Creating a comfortable and healthy dormitory environment is essential to the learning and life of college students.A variety of indoor and outdoor factors affect the student dormitory environment in winter.Under the existing conditions,the most preferred option to improve the dormitory environment of colleges and universities is natural ventilation,but the current quality of the dormitory environment in northern colleges and students'window-opening ventilation habits in winter are not clear.The impact of outdoor wind speed,temperature,building spacing and dynamic personnel activity on the indoor environment is unclear.Therefore,this article takes the influence of natural ventilation on the dormitory environment of a winter dormitory in a northern university as the research object,investigates the current outdoor and indoor environmental conditions in winter,and explores ways to improve the indoor environmental quality through natural ventilation.First,a questionnaire survey was conducted on 600 students at school and found that91.14%of the tested students had the willingness to open windows naturally during the winter;using data processing software to carry out correlation analysis,the results showed that students living in dorms that do not open windows are more likely to get sick And the evaluation of dormitory comfort is lower.Secondly,the data analysis of outdoor AQI and particulate matter levels in Jinan City in winter in the past three years shows that the risk of outdoor pollutants diffusing into indoors with window ventilation in winter is low.At the same time,the dormitory was monitored for168h indoor environmental parameters,and it was found that the air quality of the dormitory was poor.The CO₂ concentration was maintained above 1000ppm for a long time,and the ACH of the dormitory in 31.43%of the time period met the national standard 0.7 times/h.There is a problem of insufficient ventilation in college dormitory in winter.Then,consider the outdoor wind environment to establish a full-scale building model,use computational fluid dynamics?CFD?software to analyze the natural ventilation in the dormitory under steady state conditions,and use the PMV-PPD thermal comfort index and air age to evaluate the indoor environmental quality.The results show that the increase in outdoor temperature will not continuously improve the quality of the indoor thermal environment,and may also lead to indoor heat.When the wind speed is 1m/s,the temperature is 0?,and the balcony window and outer window opening area is 0.2m² In the rest area,the PMV value in the range of-0.1⁺0.6 is closest to the thermally neutral environment,and the air age in the rest area is 3033.18s.As the wind speed increases,the mixing effect of hot and cold air at the entrance of the outer window is weakened;the ventilation area of the balcony window and the outer window of the best low temperature weather with an wind speed of 1m/s and an extreme temperature of-10?is 0.02m²;Increasing the building spacing can improve the indoor thermal environment and ventilation efficiency.Excessive building spacing will cause the indoor environment quality to decrease.Finally,establish a dormitory model that considers personnel and radiant heat sources,and analyze the natural ventilation status of the dormitory under transient conditions using CFD software;the results show that at the inlet temperature Tr=5?,the inlet wind speed Vr=0.1m/s and Tr=5?,Vr=0.3m/s and Tr=0?,Vr=0.1m/s,the required window opening duration for indoor CO₂ concentration to below 1000ppm under three operating conditions is1200s,720s and 1200s respectively,and above The indoor temperature of the three working conditions is maintained above 16?,and student activities are the factors that have the greatest impact on the dormitory environment.This study investigates the effect of natural ventilation windows on the indoor environment of northern university dormitory in winter.Through field investigation,field testing and numerical simulation methods,it provides a reference for indoor environment monitoring and intelligent ventilation of university dormitory,and provide a theoretical basis for the design and optimization of dormitory natural ventilation system.