Development of a Wearable Thermo-Conditioning Device Controlled by Human Factors Based Thermal Comfort Estimation

Abstract

Today in Japan, comfortable lifestyle and environment realized by abundant electric power is being questioned by energy consumption reduction policies called “cool biz” in summer, and “warm biz” in winter. One reason of these policies is the bad energy consumption efficiency of current airconditioning systems that cool or warm indirectly human body. Several researches have been investigating the effect of direct human body cooling and warming. However, most proposed solutions focus on direct head or neck cooling, using ice to cool a water circulating system, such temperature during use cannot be controlled accurately nor adapted to user and environment conditions. If the system can automatically perform the optimum warming and cooling operation, it becomes also possible to present an optimum thermal cooling environment for children and physically handicapped persons who have difficulties to control cooling/warming operation by their own will. In our objective of developing effective energy saving technology for direct thermal conditioning of human body, we have proposed and developed a Peltier element based neck-mounted wearable device that directly cools or warms human body based on estimation of user’s thermal sensation by biological information. The thermal sensation estimation algorithm was tested in an environment where the thermal sensation of Cold, Neutral, and Hot can be obtained. Obtained thermal sensation estimation was in accordance with the subjective thermal sensation from each subject. However, temperature range while wearing the device was 28 to 38°C, when ideal cooling/warming function is 20 to 40°C.