A study on the thermal comfort in sleeping environments in the subtropics—Developing a thermal comfort model for sleeping environments

In the subtropics, air conditioning serves to maintain an appropriate indoor thermal environment not only in workplaces during daytime, but also at night for sleeping in bedrooms in residences or guestrooms in hotels. However, current practices in air conditioning, as well as the thermal comfort theories on which these practices are based, are primarily concerned with situations in which people are awake in workplaces at daytime. Therefore, these may not be directly applicable to air conditioning for sleeping environments. This paper, reports on a theoretical study on a thermal comfort model in sleeping environments. A comfort equation applicable to sleeping thermal environments was derived by introducing appropriate modifications to Fanger's comfort model. Comfort charts which were established by solving the comfort equation, and can be used for determining thermally neutral environmental conditions under a given bedding system have been developed. A related paper reports on an experimental study on measuring the total thermal insulation values of a wide range of bedding systems commonly used in the subtropics, which are an essential input to the comfort equation developed and reported in this paper.