Impacts of Dynamic LED Lighting on the Well-Being and Experience of Office Occupants

Abstract

As a critical factor in the built environment, lighting presents considerable influence on occupants. Previous research across static lighting conditions has found that both illuminance and correlated color temperature (CCT) affect occupants’ physiological and psychological functioning. However, little research has been conducted on the non-visual impacts of dynamic lighting with daily variation in illuminance and CCT levels. The purpose of this study is to better understand the impact of dynamic lighting on office occupants’ health, well-being and experience at a living lab. Fifteen participants were recruited to work in three office modules for four months. Four lighting conditions were designed and implemented in this study, including two static lighting conditions and two dynamic lighting conditions with a specific predefined control scheme. A prototype lighting system with enhanced control capabilities was configured and implemented to ensure the desired lighting environment protocol. Both objective methods and subjective surveys were used to assess the behavioral and physiological outcomes of interest, including mental stress, sleep, productivity, satisfaction, mood, visual comfort and perceived naturalness. The results showed that the daytime behavioral impacts were either positive or mixed. Specifically, a significant alertness increase was observed in the afternoon, indicating a potential solution to reduce the natural feelings of sleepiness during the workday. There was also a marginal benefit for mood. The nighttime impacts include a significant decrease in perceived sleep quality and sleep time after subjects were exposed to dynamic lighting. No significant differences were observed for mental stress, productivity, visual comfort, or perceived naturalness. The findings present additional insights into the non-visual impacts of dynamic lighting and give recommendations for further investigations.

Should We Re-think Regulations and Standards for Lighting at Workplaces? A Practice Review on Existing Lighting Recommendations

“…Impacts of two dynamic LED lighting concepts with illuminance and CCT gradually decreasing between 1:30 p.m. and 5 p.m. were investigated on its effects on sleep and well-being ( 62 ). In one setting illuminance changed from 700 to 500 lx and CCT from 6000 to 3500 K, in the other from 500 to 300 lx, and CCT from 5000 to 3000 K. The settings were compared to static light (500 lx, 5000 K and 300 lx, 4000 K).…”

Reviewing the Role of Outdoor Lighting in Achieving Sustainable Development Goals

“…This influence of light in humans can impact positively and negatively through visual and non-visual perception of radiation. For example, adaptive lighting can be applied to induce desired feelings in users by changing its intensity and spectrum [25]. Some lighting systems have mood detection to identify different needs of stimulation required to enhance well-being [24], used also to enhance cognition [26].…”

“…The alertness is highly desired in the context of productivity in outdoor workplaces and traffic safety regarding drivers awareness. Many studies evaluate the effect of light level and light spectrum on productivity responses [24,25,46,47]. Alertness stimulation depends on light intensity (high illuminated areas), time of exposure and spectrum.…”

Analysis of the Impact of Working Environment Factors on Employee’s Health and Wellbeing; Workplace Lighting Design Evaluation and Improvement

“…Optimized lighting can have many positive features that are beneficial for increasing comfort and safety in the indoor environment. Several studies [10][11][12] have addressed the effect of dynamic lighting on health and well-being. A study [13] in the office environment proves that people are happier when they have the ability to control and adjust the lighting in their workplace.…”