November 18, 2024
Rethinking LEDs: What Near-Infrared Offers
Study reveals potential health benefits of including near-infrared wavelengths in modern lighting
Modern LED lighting systems have revolutionized energy efficiency, in part by excluding wavelengths of light that don't contribute to visible illumination, such as near-infrared radiation (NIR). However, a recent study published in the Journal of Environmental Psychology suggests that this exclusion might inadvertently impact human well-being. The findings raise critical questions for the lighting industry about balancing energy-saving goals with potential health and productivity benefits.
The study evaluated the effects of NIR-inclusive lighting on mood, physiological stress responses, and cognitive performance in a controlled indoor environment.
Researchers compared standard LED lighting to LED systems enhanced with NIR wavelengths (875 nm and 960 nm). The results uncovered both benefits and unexpected limitations:
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Mood Enhancements
Participants reported feeling more pleasure under lighting with NIR exposure. This effect was likened to the psychological comfort associated with natural light phenomena like morning sunlight or firelight. -
Physiological Benefits
NIR-inclusive lighting improved heart rate variability (HRV), a marker of reduced stress and enhanced cardiovascular health. Participants also showed better adaptive responses to cognitive stress, indicating improved physiological resilience. -
Cognitive Performance Limitations
Contrary to expectations, NIR-inclusive lighting did not improve cognitive performance and slightly hindered visual search tasks. These findings suggest that while NIR benefits mood and physiology, its cognitive effects are complex and warrant further investigation.
Implications for Indoor Lighting
The exclusion of NIR in modern architectural lighting systems, while efficient, could have overlooked the nuanced role NIR plays in human health. Given that people spend the majority of their time indoors under electric lighting, these findings could have significant implications in the future of lighting design:
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Health vs. Energy Efficiency
NIR wavelengths are invisible and considered unnecessary for illumination, which has led to their exclusion to reduce energy consumption. Yet, the study suggests that ambient NIR exposure may enhance mood and reduce stress, creating a potential tradeoff between energy efficiency and occupant well-being. -
Preliminary but Provocative
The researchers caution that these findings are preliminary, emphasizing the need for more studies to validate the health benefits of NIR in ambient lighting. However, the data suggests an opportunity for the lighting industry to explore new designs that integrate NIR in energy-conscious ways.
"This study provides preliminary evidence that ambient near-infrared (NIR) exposure in architectural lighting can influence both physiological and psychological states. Specifically, these early findings indicate that ambient NIR exposure may positively influence parasympathetic activity through increased resting HF-HRV and supporting adaptive HF-HRV responses to cognitive demands."
— Excerpt from Journal of Environmental Psychology
Forward-Looking Questions
This study raises compelling questions for components makers, manufacturers, designers, and facility managers. Could advancements in LED technology allow for the selective inclusion of NIR without significantly increasing energy usage? How can the industry quantify the health and productivity benefits of NIR to justify potential tradeoffs?
As the lighting industry continues to innovate, it may look to create systems that balance energy efficiency with emerging evidence of health benefits. The potential to improve indoor environments could redefine priorities, possibly shaping a new era of human-centric illumination.
"Effects of Near Infrared Radiation in Ambient Lighting on Cognitive Performance, Emotion, and Heart Rate Variability"
Authors & Affiliations
- Charlotte M. Roddick, Yuxiao Wang, Frances S. Chen, Jiaying Zhao, Yeon Soo Seo, Wenjing Cao, Lorne A. Whitehead – University of British Columbia, Vancouver, Canada
- Dorukalp Durmus – Pennsylvania State University, University Park, United States
- Michael P. Royer – Pacific Northwest National Laboratory, Portland, United States
- Jennifer A. Veitch – National Research Council of Canada, Ottawa, Canada
