Summer sleep quality and change of bedroom thermal environment - From the beginning to the end of sleep

Abstract

Relations between bedroom thermal environment changes and subjective sleep quality and thermal comfort were surveyed for 63 apartment occupants during midsummer in Osaka. Changes of Wet Bulb Globe Temperature (WBGT) of 123 air-conditioned and 41 naturally ventilated nights were compared. 1) For air-conditioned bedrooms, sleep quality was better for smaller changes of WBGT from the beginning of sleep and for faster changes of WBGT to constant from the beginning of sleep. 2) For naturally ventilated bedrooms, a) WBGT increased from the beginning of sleep and decreased toward the end of sleep for higher sleep quality nights. However, WBGT decreased from the beginning of sleep and increased toward the end of sleep for lower sleep quality nights. b) The WBGT change was smaller for thermally comfortable nights.