Effects of bedding insulation and indoor temperature on bed microclimate and thermal comfort

Abstract

Bed microclimate can directly affect the thermal comfort of the human body. A study combining experiments and field measurements was conducted to determine the effects of bedding insulation and indoor air temperature on bedding temperature and thermal comfort. The experiments involved varying indoor air temperatures (14, 18, 22, and 26°C) and bedding system insulations (3.1, 3.7, and 4.4 clo). Six male college students participated in the experiments, and three of these also participated in the field study along with a further three to give a total of six participants in the field study. Six participants each completed 4 experiments of 3 hours duration for the experimental part of the study. The two-week field study was conducted in students’ respective dormitories, where measurements of bedding temperature and feedback on thermal perceptions were obtained. The experimental results indicated that the higher the bedding insulation and indoor air temperature were, the warmer the participants felt. Linear relationships were found between air temperature and bedding temperature, air temperature and skin temperature, and bedding temperature and thermal sensation vote. Different body parts, except for the head, shared similar sensitivities to the bedding temperature but have varying thermal requirements. The thermal neutral bedding temperature in the experiments was 31.1°C whereas that in the field study was 32.1°C. This difference could have arisen due to metabolic rates, anticipated control, and self-adaptive behaviors. Based on measured data, a comfort zone for bedding insulation and air temperature was developed to further investigate the sleeping environment and its impact on daily life.