Effects of illuminance and correlated color temperature on emotional responses and lighting adjustment behaviors

Abstract

This article presents a novel approach to assessing human reactions to indoor artificial lighting and lighting adjustment behavior. Participants (n = 27) were each exposed to 17 different lighting conditions via selected combinations of seven illuminance levels and seven different correlated color temperatures (CCTs) in a virtual office environment. We collected data about emotional valence, arousal, adjusted values, and adjustment uncertainty (via the number of button presses) in each lighting condition. We also considered potential gender effects in the responses to the lighting. The study confirmed the presence of “anchor effects,” in which starting conditions significantly impacted subsequent preferences and adjustment behavior. After multiple randomized trials, we also found that lighting preferences shifted toward reduced illuminance. Moreover, women were found to have a lower preference for illumination levels and correlated color temperature than men. A greater Adjustment Uncertainty for illumination was associated with lower illumination values (<290 lx), while this was peaking at mid-range levels for CCT (3500 K–5500 K). The variety of behavioral response profiles we found in lighting adjustment, along with the likely impact of gender and other demographic variables, highlights the importance of customization options in lighting design for higher indoor environmental quality. This research supports architects and engineers in creating lighting designs attuned to occupants' emotions, preferences, and adjustment behaviors while emphasizing the benefits of using VR simulations in the AEC industry to assess lighting design impacts on users.