Artificial skylight effects in a windowless office environment

Publication date: 1 November 2017
Source:Building and Environment, Volume 124
Author(s): Markus Canazei, Wilfried Pohl, Harald R. Bliem, Markus Martini, Elisabeth M. Weiss
Research on the effects of windows has clearly indicated that humans want and need daylight to perform and feel well in indoor environments. However, until now, beneficial skylight effects have rarely been investigated. The present laboratory study aimed to quantify temporary artificial skylight effects using a randomized controlled study design. One hundred healthy young subjects either stayed in a windowless office environment that was illuminated by fluorescent lamps or an artificial skylight system that provided a virtual view of a cloudless sky and sun. Subjects rated room atmosphere parameters and their mood states, and participated in two different decision-making tests. Our results indicated that study participants felt more connected to the nature and perceived the windowless test room as more “lively,” and less “tense” and “detached” under artificial skylight as compared to that under fluorescent illumination. Furthermore, under artificial skylight, subjects reported lower feelings of tension, anxiety, and claustrophobic symptoms, and a higher positive mood state. Finally, subjects made riskier as well as more selfish decisions under artificial skylight. Thus, daylight-substituting technologies may profoundly influence mood states and alter decision-making behavior in windowless environments.

Graphical abstract