A STUDY ON THE EFFECTS OF THERMAL COMFORT ON SLEEP QUALITY IN A NATURALLY VENTILATED SLEEP ENVIRONMENT IN SINGAPORE

Abstract

While there has been many research conducted on thermal comfort, the effects of it on sleep has not been widely explored, especially in the case of sleeping in a naturally ventilated environment. In order to help Singapore become a net-zero nation by 2050, high energy appliances like the air-conditioner should be used sparingly. For this pilot study, the effects of thermal comfort on sleep quality in a naturally ventilated sleep environment is investigated in a 4-room flat of a public housing estate in Singapore. An experiment was conducted to observe the effects of changes in thermal conditions on sleep quality, over a period of 6 days. The subject was scheduled to sleep in various naturally ventilated conditions, where data of the four environmental parameters of thermal comfort were logged using appropriate equipment. In order to have a holistic thermal comfort assessment, the adapted PMV model was first used for analysis and later substantiated with results from the subject’s votes for three other thermal comfort assessment scales. While changes in the thermal conditions of the sleep environment affects sleep quality, the impact of these changes were not significant. Moreover, thermal preference of the subject has negligible effects on sleep quality, as compared to thermal sensation and comfort perception. It is found that relative humidity has the highest impact on sleep quality. A set of acceptable ranges of the four environment thermal comfort parameter is tabulated. The author hopes that the findings from this pilot study is able to provide some insights to encourage further studies to explore passive design for residential homes in tropical climates to reduce energy consumption.