To provide employees with thermal satisfaction and improve workplace productivity, subjects were studied during a cooling period in an office room temperature modulation protocol that takes into account aspects of human circadian rhythm. The following findings were obtained in this paper.

Task performance was improved by setting the room temperature 1℃ lower than 27℃ during morning hours and after lunch.

Sleepiness tended to be ameliorated by setting the room temperature 1-2℃ lower than 27℃ during postprandial working hours.

No correlation was found between room temperature and task performance, even when the temperature was increased in the evening.