Questionnaire survey and field investigation on sleep thermal comfort and behavioral adjustments in bedrooms of Chinese residents

Abstract

Thermal comfort is one of the key factors affecting human sleep. This study aimed to provide new understandings on sleep thermal comfort in residential environments by investigating the characteristics of behavioral adjustments and exploring the relationship among indoor thermal environment, bed microclimate and sleep thermal comfort. Both online and field surveys were conducted in China. Two large-scale online questionnaire surveys were carried out in winter and summer, a total of 4127 valid samples were collected. The field study was conducted in 14 bedrooms and was divided into two periods in summer and winter, each period lasted for 2–3 weeks. The field study involved continuous monitoring of bedroom air temperature, bed temperature and daily collection of post-sleep questionnaires and collected 461 valid samples. Based on the collected data, people’s adjustments of bedding systems in different indoor environments were analyzed systematically from several aspects, including the components on both the covering side and the underlying side, the coverage forms, the total thermal insulation of bedding systems. The use of two heating modes during sleep (space heating and bed heating) were investigated and the effects of regional and personal factors on the usage were explored. Under the influence of behavioral adjustments, thermal sensation during sleep was found to be weakly correlated with overnight bedroom air temperature, bed temperature was not correlated with overnight bedroom air temperature.