Comparison of mood and task performance in naturally-lit and artificially-lit environments

The article presents the results of a laboratory study conducted at Shanghai Tongji University. The study compares participants’ mood and task performance between naturally-lit and artificially-lit environments, with a view to identify negative impacts, such as lighting variation and temperature asymmetry caused by dynamic natural light. It was observed that the mood change in the naturally-lit environment was more significant, especially the decrease of positive mood, than in the artificially-lit environment. For the subjects in the naturally-lit environment, performance scores decreased with increase in the light intensity and temperature asymmetry. Based on the study results, suitable daylighting design was recommended for classrooms or offices.