Human-Centric / Tunable-White Lighting


Light is essential, like air and water. Natural light affects many aspects of human existence and quality of life. As our modern lifestyles compel us to spend more time in artificially lit surroundings, there are consequences for our well-being. Human Centric Lighting (HCL) addresses this by tailoring indoor lighting by Correlated Color Temperature (CCT, conventionally expressed in kelvins, using the symbol K), illuminance level, time of day, spectrum, and other special human needs.

The benefits of HCL include increased comfort, improved well-being, reduced anxiety, engaged learning, higher productivity, faster recovery time, customized ambiance, and superior retail experiences. Lighting market segments – hospitality, retail, education, commercial, and healthcare – are gradually realizing the value of HCL. For these reasons, HCL has captivated the attention of architects, lighting specifiers, interior designers, and building owners.

Human-centric lighting puts people at the center of lighting design. It considers both the visual and non-visual effects of light from a physiological and psychological perspective and extends the scope of lighting beyond the traditional architectural design approach which focuses on aesthetics, visibility, and safety.

Tunable-white technology enables human-centric lighting applications. By adjusting the color temperature of a luminaire’s white light output, tunable-white technology creates artificial light that mimics natural daylight and its daily warm-to-cool cycle. And this is important to those that spend many hours indoors. Studies have shown that people may receive a number of benefits including better focus, sleep, and general feelings of wellness when they have access to nature’s 24-hour daylight cycle.

CCT Tuning

Human bodies are attuned to the light of the sun and the effect of the circadian clock extends to sleep, mood, alertness, productivity, and health, far beyond the visual perception of light. The period shortly after sunrise or before sunset is between 2000K-3000K depending on place and weather, and warmer white lighting is good for relaxing and general activities.

The noon sun or a clear sky is between 4900K-6000K, and cooler white lighting is more conducive to higher productivity, alertness, and concentration. People working in enclosed areas with no windows show higher levels of fatigue than workers exposed to daylight.

The cognitive performance of students improves when light settings are distinctly customized for calm concentration versus energetic participation. Studies have shown that hospitalized patients recover faster when exposed to indoor lighting that mimics natural light, and dementia patients display less anxiety. As CCT and illumination levels are both important for HCL, it is critical that the LED luminaire LED array and driver support a 1800K-6500K CCT tuning range with deep dimming in 0.1% steps to <1%.

Simplified integration with the Encelium X Light Management System

Multiple manufacturers of LED luminaires and LED luminaire drivers provide tunable-white solutions that are all compatible with Encelium X. As an example, the OSRAM OPTOTRONIC® Tunable White LED Driver and PrevaLED® Tunable White Light Engine work seamlessly with Encelium X.

The addition of tunable-white technology to any Encelium X project is effortless for all stakeholders. On-site installation is straightforward. Controls wiring uses 2-wire GreenBus or DALI cables for wired applications, simplifying the installation process your electrical contractor will go through. And wireless control installations are even simpler, requiring fewer contractor labor hours.

Digital control enables consistent luminaire performance

DALI Type 8 digital control commands ensure consistent and high-quality light levels across multiple luminaires regardless of the size of the space. This uniform performance is particularly noticeable in large spaces such as open office designs, corridors, and lecture halls where you can see a difference in the color and intensity of light levels. With a 0-10V tunable-white solution, a color temperature on the light output is derived from an analog voltage. One of the technical limitations of analog control is that it is prone to noise and the voltage drops as it travels the length of the wiring. Therefore the voltage read by each fixture on the same wiring can be slightly different. The fixture at the end of a line will exhibit a different color temperature than the fixture closest to the control source.

Encelium X Tunable-White solutions

Encelium X allows facility managers and occupants of spaces to take full advantage of the benefits of tunable-white lighting. From automated color temperature adjustments throughout the day, establishing preset color temperature and intensity settings for defined activities, or providing elegant user touchscreens and keypads for specific at-the-moment settings, Encelium can meet any tunable-white requirement.