Study On Nighttime Thermal Comfort And Indoor Air Quality Of University Air-conditioned Dormitories In Guangzhou In Summer

College students dormitory is an important place which students will gather at night,has many characteristics,such as long service time,crowded.Thermal environment and air quality is directly related to students' sleep quality,influence on students' learning efficiency during the day.It's hot in Guangzhou in summer,a growing number of colleges start installing air conditioner in students' dormitory.Because of lack of fresh air,poor indoor air quality is a common problem in air-conditioned dormitories,affecting students' physical and mental health.Therefore,it is of great significance to study the nighttime thermal comfort and indoor air quality of university air-conditioned dormitories in Guangzhou in summer.By conducting a questionnaire survey aimed at college students in Guangzhou on thermal environment and indoor air quality during summer days,this paper investigates students' daily routines and subjective experiences of thermal environment in dormitory.Subsequently,field tests are administered to explore the impact of the setting temperature of air conditioner,the velocity of wind and working hours on indoor temperature,humidity,the velocity of air and the carbon dioxide concentration.With a combined method involving the field test and the subjective investigation,indicators such as thermal neutral temperature and expected temperature in dormitory at night are accordingly engendered.Ultimately,through simulated data of mechanical ventilation mode,different mechanical ventilation and control of pollution sources approaches in dormitory are simulated to analyze and compare the effect of different indoor air distribution on CO2 field.Results show that students lack of scientific guidance on setting of air conditioner parameters and students are dissatisfied with thermal environment and air quality in dormitory during sleep.Indoor environment deteriorate during sleep.Air conditioning dormitory indoor air temperature and relative humidity are greatly influenced by the air conditioning set temperature and setting wind speed of air conditioner has just a little influence on it.The lowest temperature in air-conditioned dormitory will be 2 ~ 3? higher than the setting temperature.The indoor thermal environment can conform to the specification while the setting temperature is 24?.With Setting air conditioning wind speed higher,the indoor ventilation volume is larger,the smaller the CO2 density.Stop running air conditioning,the indoor CO2 concentration rise rapidly and density stratification shows up,CO2 level in breathing zone is the highest,up to 1839 ppm.The thermal neutral operating temperature of students at night in Guangzhou is 28.0?,the range of acceptable temperature is 24.7 ~ 31.3?,the expected temperature is 27.6?.The indoor thermal environment can be satisfied while the setting temperature is 24?.Because of the air conditioning,mechanical inlet and natural exhaust mode can't effectively enter the main area of dormitories.Mechanical exhaust and natural inlet mode can reduce CO2 level below 1000 ppm.The number of students in the dormitory was reduced from 4 to 2,CO2 level can be reduced to 700 ppm.With CO2 source is closer to air conditioning and ventilation equipment,the faster the CO2 can be sent to outdoor or indoor unmanned area,CO2 concentration in main area is lower.