Field Study On Human Thermal Adaptation In University Classrooms And Domitories In Severe Cold Area

Adaptation is the potential of human survival, and the adaptation to thermal environment is inevitable. The thermal adaptation in different climat zones is various. The winter in severe cold zone is long, and the outdoor temperature changes throughout the winter which is similar to the changes between different seaons in cold regions. So human thermal adaptation maybe different in each period in winter. Besides, under two different indoor environments, human thermal adaptation may be different.The study focouses on the thermal apatation to the envirionment and thermal comfort in university classrooms and dormitories. Combined a field study with subjective questionnaires, we conducted a 8-months investigation in 5 classrooms and 11 domitories. 30 university student-subjects were surveyed once a week. Based on the results of human thermal responses in different heating periods and environments, we get the following conclusions.First of all, the average indoor temperatures in classrooms were close to or beyond the upper limit of 24℃ in the thermal comfort standards. About 50% of subjects felt warm, indicating the classrooms were overheat. The neutral temperatures were all lower than the air temperatures and predicted neutral temperatures. In heating periods, the neutral temperatures gradually increased, which indicates that human adaptation to the environment. The lower limits of 80% acceptable temperatures were lower than 14℃ in heating periods, which means that people had tolerance to cold ambient environment in winter. The subject’s clothing insulation in different periods were different. It was related to the indoor temperatures in heating period.Secondly, the indoor temperatures in dormitories were all in the range of thermal comfort temperatures. Before heating, the neutral temperature was higher than indoor air temperature. However, the neutral temperatures were slightly lower than air temperatures in other periods. At the early heating period, the neutral temperature was the lowest, which declined to 20.9℃. All of the neutral temperatures were lower the predicted values, which reveals that people had better adaptation to lower temperature in winter. The thermal adaptation had positive effect on thermal comfort. In heating period, the clothing insulation had significant relationship with both indoor and outdoor temperatures.Finally, the thermal adaption models of the classrooms and dormitories in severe cold zones were established. The air temperatures and clothing insulation in classrooms were obviously higher than in dormitories, so the thermal sensation in classrooms was higher than in dormitories. The above reasons leaded to the neutral temperature in classrooms was lower than in dormitories. Those showed that the indoor air temperatures in classrooms were too warm. In both environments, the subjects took measures to improve thermal comfort, such as change clothes. But the freedom of behavioral regulation were different. When the subjects adjusted behaviors such as putting on more clothes, they felt more comfortable and this can save energy and reduce carbon emission.In summary, the indoor temperature should be close to the lower limit of the comfort range to feel comfortable and save energy. In addition, we should make full use of the human thermal adaptation, human behaviorial regulation and psychical expectation, and the indoor temperatures should be change with the outdoor temperature in different heating periods and environments.