An Experimental Study on Human Thermal Comfort with Thermal-Conductive Bed during Sleep in Summer

Sleep is vital for human health, while sleep quality is affected by indoor thermal environments. This study aims to investigate human thermal comfort with a thermal-conductive bed during sleep in summer. A series of experiments were conducted in a climatic chamber of a university. Subjects slept on a thermal-conductive bed, with or without the supply of water cooling them by flowing through the pipes embedded in the bed. The supply water was set at 20, 25, 28, and 30 degrees C. The indoor temperature was set at 32 degrees C. The bed surface temperature (back, buttock, thigh, and calf) and the subject's skin temperature were measured. Questionnaires after waking up the next morning were conducted. The results show that when there was no water supply in the pipes of the thermal-conductive bed, the bed surface temperature was 0-1.5 degrees C higher than the indoor temperature, and subjects felt slightly warm. When the supply water temperature was 28 or 30 degrees C, subjects felt thermally comfortable during a night's sleep. This study demonstrates that the proposed thermal-conductive bed with supply water temperatures of 28-30 degrees C can create a comfortable sleep environment for residents who have no air-conditioning systems in summer, which can also help save building energy.