Experimental study on thermal sensation of people in moderate activities

The motivation of this study is to get better understanding about the real thermal sensations of people who undertake moderate activities. Experiments were conducted in a climate chamber. Sixteen subjects participated in two kinds of activities: treading in situ and up-and-down a step. Their metabolic rate, skin temperatures were measured. The subjects' thermal sensation votes, sweat feeling index and air movement preference were collected during experiments. The results showed that the PMV model overestimated subjects' thermal sensation for both activities. The analysis to sweat feeling index showed that subjects' thermal sensation was related to sweat activity. And the thermal regulation process of sweat had some impact on people's thermal sensation. Furthermore, the sweating process influenced mean skin temperature, which led to the decrease of neutral skin temperature at moderate activities. A linear relation was proposed to calculate the neutral skin temperature for different metabolic rate. The relation was compared with equations of Fanger and Gonzalez, which indicated that Fanger's equation strayed from the other two formulas when metabolic rate was above 2.5 met. Analysis about air movement showed that subjects expected higher velocities as activity was intensified.