Human-Centric Lighting – Many Benefits in the Post-Pandemic World
Light is rarely the focal point of a space. Aside from a rainbow after a rainstorm or a sunset over the ocean, we often don’t even see light, we just see with it. That may be one reason lighting considerations occur as an afterthought for many facilities. Despite the significant energy efficiency improvement LED lighting brought over the past decade or so, lights typically fly under the radar of a building’s occupants. However, the coming wave of Human-Centric Lighting (HCL) technologies and products will bring the discernable impacts of lighting to a whole new level, one which has been previously “unseen” since the time electric lighting was first commercialized back in the Thomas Edison days. A breakthrough development in the evolution of HCL is the ability to integrate self-contained UV-C disinfection within the units that can continuously reduce pathogen levels in the air, while preventing human exposure to harmful UV rays.
Human-Centric Lighting: Integrating Technologies Today, Preparing Us for Tomorrow
HCL describes LED lighting that integrates various rapidly growing technologies in electronics, software, sensor and even cloud power that could create biological, physiological and emotional benefits for a facility’s occupants. HCL encompasses both the visual and non-visual benefits of lighting, from increased safety, comfort and productivity to improved mood and sleep. Integral to today’s world of pandemic “reality” we are experiencing, it is also prudent for facility managers, engineers and operators to be cognizant of the power HCL has to bring UV-C lighting to their properties, while keeping occupants safe and healthy.
Some immediate key benefits HCL is able to bring to facilities are reviewed below:
Low Flicker: Critical for Wellness and Performance
Flicker is the modulation of light output caused by the conversion from AC to DC power. The effects of flicker are dependent on the frequency of modulation, the ambient lighting situation and the sensitivity of occupants exposed to the lighting. These effects range from headaches, fatigue, and eyestrain to reduced task performance, according to IEEE, and flicker in the 3 – 70 Hz frequency range can even induce photosensitive epilepsy. Flicker was first introduced with magnetic ballasts for fluorescent lamps, then removed with higher quality electronic ballasts, and then re-introduced with lower quality LEDs that have flooded the market in recent years. Ensuring that only lamps that have low flicker (UL defines “low flicker” as below 1%) through electronic circuit designs used in your facility is critical for the wellness and performance of your occupants.
Adjustable Color Temperature: Improving Alertness and Focus
Color temperature denotes the spectral distribution (the concentrations of particular wavelengths) of light and is often referred to as “warm” or “cool.” It is measured in Kelvin (“K”), referring to the color a metal object heated to that Kelvin temperature would naturally radiate, according to National Institute of Standards and Technology. Warmer, yellower light (closer to 3000K) evokes a sense of calm and relaxation; whereas cooler, bluer light (closer to 7500K) improves alertness and focus and has been shown to increase productivity, according to Journal of Circadian Rhythms.
Circadian Lighting: Optimizing Lighting for Health and Wellness
Circadian lighting aims to optimize light levels and color-temperature of the lighting to align human bodies to the 24-hour sleep-wake cycle, or “circadian rhythm,” based on the rising and setting of the sun. All living organisms on Earth exhibit circadian rhythms, which govern a wide array of cyclic physiological processes from melatonin secretion to immune responses. These rhythms are regulated or entrained by environmental cues, the primary cue being the natural light-dark cycle. Typically, higher color temperature and higher amount of light is beneficial during working hours to suppress melatonin and keep us alert and productive, and lower color temperature and lower amount of light during late afternoon to evening would allow the secretion of melatonin for better sleep. An effective circadian lighting system may help improve the health and well-being of building occupants, according to research published by The Lighting Research Center and some research, such as a study published in Translational Psychiatry, has shown it may even reduce anxiety and depression. The research by the Lighting Research Center also indicates that when circadian rhythms are out of sync, people may experience issues with physiological function, neurobehavioral performance and sleep. In addition, there appears to a higher risk for cardiovascular disease, diabetes and certain cancers.
Ultraviolet Germicidal Irradiation: Self-Contained Units Integrate With HCL Lighting Technologies
Going beyond the visible spectrum of light, HCL can bring about even more potent health and wellness benefits. Ultraviolet Germicidal Irradiation (UVGI) has been used in air treatment systems for decades to destroy a wide array of indoor air pollutants. UV germicidal lights disinfect the air by emitting short wavelength light (or radiation), in the 200 – 280 nm range (UV-C) , according to Public Health Reports, which can damage the DNA in the cellular nucleus of bacteria, virus, and mold – rendering them incapable of replicating. However, the same destructive properties that make UV so effective at disinfection may also render it harmful to humans, as the rays emitted may also damage human skin and eye cells according to the Journal of Nucleic Acids. Self-contained UV-C disinfection units prevent human exposure to the harmful UV rays while continuously reducing pathogen levels in the air.
LED and UVGI Technologies: Gaining Financial, Environmental and Health Benefits
Recent advances in tubular LED and UVGI technologies enable simple, affordable and quick retrofits with both human centric lighting and in-room UVGI. Platforms and solutions that combine UV-C air disinfection and tubular LEDs (TLEDs) are significantly more cost-effective and environmentally friendly in both the near- and long-term. TLEDs, as opposed to integrated fixtures that cost far more and can’t be upgraded as technologies advance, grant facility managers the option to upgrade or replace lamps without replacing the entire fixture, and some are capable of both dimming and color-tuning and UVGI. There has never been a better time to direct your attention up, to your lighting, to HCL for triple bottom line benefits: financial, environmental, and health.
James Tu is Chairman and Chief Executive Officer of Energy Focus, Inc., an industry-leading innovator of sustainable LED lighting technologies and solutions.