Sleep quality and adaptive thermal comfort under various energy use modes

There are limited studies on the impact of room temperature on sleep quality, particularly outside laboratories. Also, limited studies investigated the impact of thermal control on sleep quality and energy related matters, while heating and cooling are responsible for 40% of the energy use in buildings. This work investigated the impact of thermal comfort on the sleep quality, gender differences, ventilation mode and thermal control systems, which lead to differences in the energy use. Field test studies of thermal comfort were applied between 2010 and 2014. 13,728 datasets from 61 buildings and 135 participants were collected in participants’ bedrooms in Japan. The results indicated that female participants had lower comfort temperature, as compared to men, before sleep during the cold months. Otherwise, no significant difference was found between their comfort temperatures, which is in disagreement with the existing research. The sleep quality was improved when thermal sensation was between slightly cool and neutral; and the comfort temperature between 17-27°C. Natural ventilation had a consistent impact on the sleep quality, as compared to heating and cooling modes. Opening a window improved the sleep quality during the warm months; while reduced it during the cold months. This suggested extra care regarding the natural ventilation to improve the sleep quality and to reduce the energy demand of the building.