Changes in indoor thermal environment before and after heating insome dormitories of a university in Beijing and their effect on students’ thermal comfort during sleep

In order to explore the differences in the thermal environment of the dormitories before and after heating and their impact on the students’ thermal comfort during sleep, 8 dormitories with different orientations are investigated in a university in Beijing, and the sleep quality of 16 students is obtained by combining questionnaire survey and sleep bracelet monitoring. The results show that the average indoor temperature in the dormitories during the night is (18.6±1.1) ℃ before heating and (20.2±1.4) ℃ at the initial stage of heating, which meets the standard requirements. During the measurement period, the relative humidity of the dormitories at night is higher than 30%, which meets the comfort requirements. The total thermal resistance of the bedding system is about 3.5 to 4.9 clo, of which the thermal resistance of pajamas is about 0.03 to 0.40 clo. At the initial stage of heating, the thermoneutral temperature before bedtime is 18.0 ℃, and the acceptable temperature range is 16.0 to 19.8 ℃. When waking up in the morning, the subjects prefer warmer conditions. There is a significant correlation between the thermal sensation before bedtime and the sleep quality, and when the subjects feel warm before bedtime, the sleep satisfaction is better and the proportion of deep sleep is higher, which is more conducive to sleep.