Study Of Indoor Thermal Comfort Of Residential Buildings In Xi’an

With the improvement of people’s living standards and the rapid increases of energy use,the creation of a comfortable living environment which ensure the effective use of resources has become an urgent problem which should be solved.In order to study the thermal comfort status of residential buildings in Xi’an,field tests and questionnaire surveys were conducted in winter,spring,and summer.The on-site testing mainly focused on testing the current thermal environment parameters of the room.The questionnaire survey included people’s subjective thermal sensation,wet sensation,wind sensation and people’s dress,activity level,in which ASHRAE’s7-grade thermal sensation scale records the subject’s subjective thermal response.The collation and analysis of data include two aspects:One is based on the season,the work include sorting out the distribution of the seasonal environmental parameters,clothing thermal resistance,and subjective thermal sensations;and analyzing the relationship between the actual thermal sensation vote(AMV)and the predicted mean thermal sensation vote(PMV)in each season.Then we get the corresponding thermal neutral temperature,and analyze the changes between them and find a way to correct them.In accordance with China’s design standards,the corresponding thermal comfort zones are obtained with different thermal comfort levels.The results showed that :in the winter,the PMV value underestimates the actual thermal sensation of the human body.But it’s the opposite in the summer.In the transition season,the PMV value is closer to the AMV value,which had a better prediction effect on the actual thermal sensation.In the winter,spring and summer,the actual thermal neutral temperature is 18.7°C,23.9°C,26.9°C,respectively,The temperature of thefirst-class thermal comfort zone fall into the range of 16.1~21.2°C,21.2~26.5°C,and25.0~28.8°C,respectively.The temperature range of the secondary thermal comfort zone is 13.5~23.8°C,18.6~29.8°C,and 23.1~30.7°C,respectively.Second,based on the one year,long-term monitoring of indoor and outdoor temperature changes in six households,and analyze the change of the indoor temperature and humidity with the outdoor temperature and humidity.And then analyze the environmental parameters,clothing thermal resistance,PMV and AMV values how to change with the seasons.Sort out the results of questionnaire survey on the daily behavior of residents in Xi’an,analyze the distribution of active regulation behaviors of residents to improve the comfort of indoor environment.The results showed that the correlation between air temperature and outdoor temperature is not significant in winter and summer.The indoor and outdoor temperature difference in winter is greater than that in summer;while the indoor air temperature in spring and autumn changes significantly with the change of outdoor temperature.Through the data analysis and analysis of field tests,we found that indoor air temperature,radiation temperature,wind speed,and relative humidity gradually increased with changes in winter,spring,and summer seasons,while the clothing thermal resistance decreased.Throughout the year,the actual thermal sensation temperature of the human body was 22.9°C,and the temperature range of the first and second comfort zones was 19.4°C~26.3°C and16.0°C~29.7°C,respectively.It also showed that the reason of the difference between the PMV value and the AMV value mainly comes from the behavioral,psychological and physiological adaptability of the human body.It provides the basis for the design of indoor parameters,which is for the realization of the effective balance between indoor human thermal comfort and building energy conservation in residential buildings in Xi’an.