Impact of natural window views on perceptions of indoor environmental quality: An overground experimental study

Abstract

• People's thermal sensations move towards the neutral level when with a window. • Natural window views can enhance people's adaptation to slightly dark environments. • Natural window views can significantly improve people's overall comfort level. • Natural landscapes' effects on occupants are more psychological than physiological. Visual connection with natural elements has been shown to contribute to emotional and physical health, as well as to productivity. This study assessed the main effects of natural window views on subjective perceptions of indoor environmental quality and physiological parameters. We conducted a laboratory experiment with 22 participants in spaces with and without natural window views. The indoor temperatures were set to 23, 26, and 28°C, and the illumination to 150, 300, and 500 lx. Environmental and physiological parameters were monitored and responses to subjective questionnaires were collected. The results showed that participant's thermal sensations move towards the neutral level when with natural window views, especially under slightly warm conditions (28°C, votes decreased by 0.36). Additionally, participants with natural window views showed a 0.4 improvement in luminous sensation and a 17.5% reduction in eye symptoms under 150 lx. The window increased participants' ratings of overall comfort by 0.23 and decreased the effects of temperature and illumination by 2.7% and 2.3%, respectively. Decreasing pulse rate and increasing arterial oxygen saturation (SpO 2 ) in the window space reflected the relief of stress and fatigue. The reduction in cooling and lighting requirements demonstrates the potential energy-saving benefits of windows.