Abstract
This paper reports our research findings of a joint influence of several environmental factors -sunlight, outdoor view, privacy, and control- on room occupants’ cognitive performance. An experiment with one hundred subjects showed that the amount of daylight and sunlight alone was not evident for subjects’ cognitive performance; instead, multiple environmental factors have significant effects. The combined effect of the above environmental factors at a level of sixty percent was optimal for performance. This finding is in agreement with the optimal arousal theory, which suggests that an optimal level of arousal is at a certain moderate value for most day-to-day activities. It suggests that the commonly believed benefits of daylighting on improving building occupants’ performance may only take effect on condition that the other factors are in an optimal range. This study, for the first time, reveals the importance of non-luminous factors, privacy and control, in daylighting design.
