A study on the thermal comfort in sleeping environments in the subtropics—Measuring the total insulation values for the bedding systems commonly used in the subtropics

The total thermal insulation value of a bedding system significantly affects the thermal neutral temperature for sleeping environments and is therefore an important variable in the Comfort Equation developed for sleeping environments reported in a related paper. This paper reports on the measurement of the total insulation values for a wide range of bedding systems (through different combinations of bed, bedding and its percentage coverage over a human body, and sleepwear) commonly used in the subtropical regions using a thermal manikin. The total insulation values of the measured bedding systems varied greatly from 0.90 to 4.89 clo, depending upon bedding, bed and mattress, the type of sleepwear, and percentage coverage of body surface area by bedding and bed. The use of a Chinese traditional style bed—Zongbang bed can provide less insulation than the use of the conventional mattress commonly used in Hong Kong. The use of so-called air conditioning quilt (summer quilt) cannot help lower the total insulation significantly. On the other hand, some factors such as people sweating and moisture permeability of the quilts, etc., were not considered in the current study but may be further studied in future work.