Indoor Thermal Comfort of College Dormitory during Winter in a ‘Hot Summer-Warm Winter’ zone A Case Study in Shenzhen University

Cao, Danlun [UCL]

In recent years, with the enhancement of economic strength and scientific and technological level, China's higher education has developed rapidly. Universities around the country continue to expand the campus to cope with the increasing number of students. Dormitory is an important kind of educational building, its built environment is directly related to students' learning efficiency and physical, mental health. At present, due to the improvement of people's living standards, indoor thermal environment of dormitory often cannot meet the living needs of students. Thus, the research on indoor thermal environment and the improvement of thermal comfort in college dormitory has become an urgent problem to be solved. There are many different regions in our country as well as many different types of climate. Taking Shenzhen University as an example, the study has pioneered in studying the indoor thermal comfort in hot summer and warm winter zone. Firstly, the study introduces the development process and current situation of research on thermal comfort at home and abroad, and then introduces the theoretical basis of thermal comfort from the aspects of thermal comfort model, influencing factors of human thermal comfort, thermal comfort evaluation index and standard. Then it selects representative dormitories for field study. The objective study is to measure the physical environmental parameters such as indoor temperature, humidity and wind speed of the spot; subjective study is a questionnaire survey, the questionnaire collects the subjects' perception and expectation of each environmental parameter according to ASHRAE Seven-level scale and Three-level scale. By comparing the subjective and objective results, the indoor thermal comfort of the dormitory was evaluated. After introducing the theory and operation process of the software in detail, the study uses Airpak to simulate the indoor thermal environment of one measured dormitory. The model is verified by comparing the measured and the simulated values in temperature field and wind velocity field. Finally, based on the model, the study innovatively quantifies the adaptive behaviors such as opening doors and windows, as well as exploring its influence on environmental parameters and thermal comfort evaluation indicators PMV and PPD. Through the above research steps, the study draws the conclusion that in winter, the indoor temperature of dormitory in Shenzhen University is between 17.5 °C and 23 °C, the indoor wind speed is concentrated between 0m/s and 0.1m/s, and the relative humidity is 75%-85%. The overall thermal sensation of the subjects in winter was “a little dissatisfied”. Although they felt a little uncomfortable, they were subjectively able to accept the thermal environment in which they were located. People in the dormitory generally adopts two ways to warm up: one is to adjust the indoor thermal environment by controlling doors, windows or other facilities; the other is to adjust the perception of the thermal environment by changing activity state and adding clothing. Among them, reducing the opening of balcony doors can improve the indoor thermal environment both in the daytime and at night. However, the other two ventilation measures can only increase indoor ventilation, and the thermal comfort of human body has not been improved. If people in the dormitory cannot change the indoor thermal environment through adjusting facilities, adding clothing or increasing activity intensity will be the best choice to help the body achieve thermal comfort. Since the facility adjustment behavior has a greater impact on thermal comfort in daytime, the individual adjustment behavior has a greater impact on thermal comfort at night, people in the dormitory should choose suitable thermal adaptive behavior according to their specific needs and time periods.