Subjective experiment on causal relationship between indoor temperature and occupants’ performance mediated by arousal state

In the present study, a subjective experiment was done to validate the causal relationship between indoor environment and occupants’ performance mediated by their arousal state. Indoor temperature was selected as the environmental parameter, and controlled at three levels (22, 25, 28^oC). The subjects’ performance was evaluated with three types of tasks (detecting wrong pairs of numbers, inputting numbers, and Sudoku). The results were obviously dependent on the tasks. When subjects engaged in either detecting wrong pairs of numbers or inputting numbers, there were almost no differences in both arousal state and performance among three indoor temperatures. However, in the case of Sudoku, the EA at 22^oC was significantly higher than 28^oC (p<0.05) and the TA at 22^oC was significantly lower than 28^oC (p<0.05). A difference in performance on Sudoku was also found between 22^oC and 28^oC at the ending of the session (p<0.1). As the reason of the dependence on the tasks, it was considered that both EA and TA subsided due to the simplicity and monotony of the tasks except for Sudoku. Thus the EA and TA became lower regardless of the indoor temperature and no differences were caused in the performance.