In order to investigate seasonal variations in the thermal comfortable environments a year round experiment on human subjects was conducted in a detached house in the suburb of Tokyo. Thirty five college-aged women were provided by the experimenter with uniform clothing, which was subject to seasonal changes (0.4clo-1.3clo). Air temperature, humidity, globe temperature and air velocity were continuously recorded and several skin temperatures, the microclimate temperature and humidity inside the clothing of human subjects were monitored. Thermal and comfort sensations were evaluated at the interval of 10 minutes. The SET* values were calculated based on measurements results and comparison was conducted for values for different seasons.
The variations in the thermal environment according to the season, time, and type of room had influenced the physiological and psychological responses of the subjects. SET* values obtained from the correlation ship with thermo neutral sensation were 25°C and 28°C in the winter and the summer, respectively. Mean skin temperature which strongly correlated with thermo neutral sensation was 33°C and 35.5°C in the winter and the summer, respectively. The comfortable zone was found to range from 24°CSET* to 29°C SET* and from 25.5°CSET* to 30°CSET* in the winter and the summer, respectively. These determined ranges of SET* values were higher than the comfortable SET* variations in the ASHRAE standard 55-2004. The difference might be considered to occur due to young female subjects and could possibly also originate in clod floor in the winter season or the air velocity in the summer season.
