×
Subscribe to Updates and Newsletters
 
 
You're Here: Home » Information » LED Lighting

Tunable White LED Lighting

Abstract: Tunable white lighting visually, biologically and emotionally contributes to human interaction with the physical world. Human centric lighting (HCL) that builds on this technology brings the dynamics of natural daylight indoors and delivers a positive effect on human health, well-being and performance.

Tunable White LED Lighting

Tunable white lighting is a dynamic white lighting technology developed to support the concept of human centric lighting (HCL). Until recently the lighting industry had been placing its emphasis on products and solutions that provide visual sensation in humans and facilitate perception of the visual environment. The discovery of a third photoreceptor in 2001 has transformed our understanding of how light interacts with the human organism. Light not only provides visual sensation through rod and cone photoreceptors, but also influences biological processes in the human body by stimulating the non-visual photoreceptor called intrinsically photosensitive retinal ganglion cell (ipRGC). Human centric lighting, which is designed to evoke non-visual human physiological responses through biologically effective lighting, was initiated on this discovery and is driving the technology trend in the lighting industry.

What Is Tunable White Lighting

Tunable white lighting refers to dynamic control of color temperature and light intensity of a lighting system, with the intention of aligning lighting with circadian rhythms or key activities that require occupants to be more physiologically and psychologically engaged. This technology harvests superior controllability and color mixing performance of LEDs to create a tunable mixture of white light. The dynamic feature of tunable white solutions allows any color temperature within the mixing range to be called up. Along with independent, full range control of light output, tunable white lighting systems can simulate the drama and variety of natural light for a positive effect on human health, well-being and performance.

The Science behind White Light

Not all white light is created equal. Similar to the way natural daylights comes in different tones, white light has its own variations in appearance. Correlated color temperature (CCT) is a color metric that quantifies the appearance of a white light source. White light with color temperatures at 3000 K or less is called "warm white" because it has a relatively reddish tone, whereas white light at 4000 K or greater has a relatively bluish tone, like moonlight on snow, and is therefore considered "cool white". And white light with CCTs between 3000 - 4000 K is called "neutral white" as it does not excessively emphasize either red or blue in its appearance. For a long time, people has related CCT to merely the visual impression of white light in different tones. But the light spectrum behind every CCT value is inherently tied to biological processes in the human body.

The human biological clock has evolved to cycle with the 24-hour rhythm of the solar day through circadian phototransduction. Circadian phototransduction is a biochemical process in which three photoreceptors (rods, cones and ipRGCs) in the retina convert received light into electrical signals for the circadian system. Among three photoreceptors, ipRGCs play a dominant role in this process. They transmit signals emanating from the retina to the suprachiasmatic nucleus (SCN) in the hypothalamus region of the brain where the circadian system is located. The SCN is the body's master biological clock which orchestrates the circadian system and synchronizes the sleep-wake rhythm to the natural light-dark cycle using signals provided by the photoreceptors. The master clock co-ordinates and synchronizes peripheral clocks located in other tissues outside the SCN. Thus the circadian rhythm established by the SCN influences various aspects of human biology, endocrinology, physiology, metabolism, and behavior.

From sunrise to sunset, the dynamic changes in the color temperature and illuminance of daylight have been genetically registered in our biology as a system of internal clocks that include the master and peripheral clocks. Melanopsin, the photopigment that drives the ipRGCs' photosensitivity, reacts specifically to light at the blue end of the spectrum. It is most sensitive to bright daylight and exhibits peak photosensitivity during the midday hours when the light spectrum contains the highest percentage of blue. Stimulated by the blue wavelengths in the daylight spectrum, the ipRGCs work through the SCN to encourage the production and release of cortisol, the stress hormone that stimulates the metabolic process and programs the body into day mode. The ipRGC photoreceptors also promote secretion of serotonin and dopamine needed for enhancing pleasure, alertness, coordination, and mood.

Exposure to bright, blue-rich light has been shown to suppress the production of melatonin that is unwanted during the day because it promotes sleepiness. Nevertheless, melatonin is a critically important hormone that decides the quality of restorative sleep during the night. Unlike cortisol, which is promoted during light exposure, melatonin is suppressed by bright light, in particular the blue-rich cool white light. As the sun sinks in the west, the daylight ambiance is stronger in the red part of the spectrum. The SCN will respond to the changes in light spectrum and reduced light intensities by signaling pineal gland to release melatonin at night and under conditions of darkness. However, a sudden introduction of bright, high color temperature light in the middle of the night will interrupt melatonin production, which can lead to fatigue during the day.

Brings the Dynamics of Natural Daylight Indoors

As presented above, light does not just provide visibility that enables us to see things and perform activities, it regulates the biological processes in our body. High intensity, cool white light with a high percentage of blue in its spectrum has an energizing effect on the human body, while low intensity, warm white light such as that of the setting sun unleashes the release of melatonin and makes people sleepy and relaxed. We spend most of our time indoors living, working, and playing under spectrally uniform and consistent artificial light. This can disrupt the natural circadian rhythms that we have been conditioned in the course of human evolution. Circadian disruption will negatively affects the entire body, including sleep, alertness, mood, digestion, immune system and physical performance. Subsequent health effects include increased cancer risks (especially for breast and colorectal cancer), depression and mood disorders, cardiovascular diseases, impaired functioning of the immune system, reproductive problems, and diabetes.

Tunable white technology allows artificial emulation of the natural cycle of daylight that defines our 24-hour internal clock. Dynamic white systems with tunable wavelengths and lumen output can be programmed to change spectral power distribution (SPD) and light intensity over the course of the day to deliver biologically effective light at the right spectrum and radiation time. Aside from synchronizing our endogenous circadian rhythm to the natural sequence of day and night, tunable white lighting can evoke particular human biological responses to achieve enhanced effects. For example, different types of daylight activities can be performed under light exposure with task-specific spectrums and intensities for maximal productivity or engagement. Tunable white lighting can also be used to create emotionally triggering environments and set appealing atmospheres that support positive psychological stimulation. A soft, warm ambiance, for example, often encourages relaxation, imparts a feeling of intimacy, and contributes to hospitality and comfort of an interior space.

How Tunable White Lighting Works

Tunable white lighting systems use wavelength or color mixing of a number of controllable channels to create the diversity of color temperatures. The mainstream method is 2-channel Warm-Cool mixing which adjusts color temperature by changing the relative intensity of cool white LEDs (short wavelength radiation) and warm white LEDs (longer wavelength radiation). The challenge for this method is to ensure CCT transition follows black body curve. The tunable white spectrum usually covers the entire CCT range from 2700 to 6500 K or 1800 to 6500 K. Simple intensity mixing of warm and cool LEDs over a wide CCT range will create a straight line that falls off the black body curve at the center. This will make the tint pink, instead of neutral tint when the color point is on the black body curve. Separate control inputs for intensity and color temperature are required to ensure that the color temperature remains constant when intensity is adjusted and vice versa. The control inputs for these fixtures can be 0-10V, CCR, PWM, DMX, or DALI control.

Additive color mixing refers to the mixing of at least three primary colors (red, green, blue) to create secondary colors. Additional color LEDs can be included to improve color quality. The benefits of primary color systems (RGB, RGBA, RGBW, or RGBAW) include that any color temperature along the black body curve can be produced and the mixture of light has excellent color rendering over the entire CCT range. RGB color mixing requires a sophisticated controller that provides signal interpretation and runs color mixing algorithms for regulating the current to individual LEDs.

Tunable White Applications

Whether in a commercial, residential, healthcare or education environment, lighting should be adapted for every occasion and activity. The ties between natural light and human health are hard to ignore. The ability to simulate the dynamics of natural daylight for various applications is a tremendous evolution in lighting. Biologically effective lighting delivers a positive influence on health, well-being, and our capacity to perform. Tunable white technology enormously widens the applications of artificial light from simply visual tasks to human centric lighting. This is a time of transforming our homes, offices, schools, hospitality spaces, and healthcare facilities to supports the trend towards HCL.

Residential

The proliferation of human centric lighting in residential applications simultaneously drives the development and deployment of tunable white products. Tunable white lighting enables people to adjust the living environment to suit varied activities, occasions, climates and seasons. This not only enhances the look of the space as a design element, but sustainably improves quality of life as the biological processes in the human body are harmonized with the cycle of natural sunlight.

Healthcare

Tunable white lighting systems deployed in hospitals and senior living facilities can be used to promote patient recovery. Personalized HCL solutions can encourage healing from depression, bipolar disorders, seasonal affective disorders, and Alzheimer's disease related dementias (ADRD).

Offices

Today's office is constant with bright, blue-rich lighting which keeps occupants alert and productive during work. This will often disrupt circadian rhythms, which translates to potential issues, including sleep and mood disorders, and consequently the ability to perform and the overall sense of well-being. Well-designed lighting can minimize the negative impact of prolonged high CCT lighting while enhancing concentration, safety and efficiency for specific tasks.

Industrial

LED light fixtures equipped with tunable lighting control provide the flexibility to meet today's stringent regulatory and environmental challenges. A circadian-friendly lighting design can create a sense of human scale in the tedious industrial environment. Workers are exposed to high CCT light which is intended to maintain their concentration and alertness as much as possible throughout the working hours. A flexible lighting scheme can be more efficient to reach this goal while improving employee satisfaction and reducing the risk of circadian disruption.

Education

The implementation of tunable white lighting systems can support improvement of the learning experience and promote higher cognitive performance in the classroom. Lighting can be tuned to support different levels of alertness and concentration in order to perform tasks with a variable degree of complexity, as well as promote relaxation and reduce fatigue during breaks.

Retail

Tunable white lighting is a powerful merchandising tool in shopping centers, retail stores and commercial showrooms. It provides flexibility to showcase changing merchandise in the best appearance and create emotions associated with various brands. It does not only accentuate the look and enhance the appeal of merchandise, but also contributes a sense of comfort to the retail experience and encourages a longer stay.

Hospitality

From the welcoming atmosphere of a hotel lobby to visually pleasant guestroom lighting to the sensational glow of an intimate restaurant, tunable white systems can create an attractive, comfortable and functional environment that contributes a feeling of hospitality and comfort.

Some more info that might interest you
Lighting Manufacturers: Thrive In or Ruin the LED Lighting Industry?
Lighting Manufacturers: Thrive In or Ruin the LED Lighting Industry?
The game changing LED technology fundamentally altered competitive dynamics in the lighting market. How do lighting manufacturers differentiate themselves and thrive i...
How Does Internet of Things (IoT) Work
How Does Internet of Things (IoT) Work
Internet of Things (IoT) drives innovations in various industries and produces massive benefits across all aspects of our lives. IoT creates a world where anything can...
Human Centric Lighting (HCL): What Is It and How Does It Work
Human Centric Lighting (HCL): What Is It and How Does It Work
Human centric lighting (HCL) synchronizes human biological clocks to the natural dynamics of a solar day. Circadian lighting uses tunable white technology to dynamical...
Advantages and Disadvantages of LED Lighting
Advantages and Disadvantages of LED Lighting
LED lighting delivers a wealth of benefits such as high energy efficiency, long operational life, spectral engineering ability, digital controllability, and solid stat...
Best Smart Light Bulbs
Best Smart Light Bulbs
Inject intelligence and autonomy into your light fixtures with plug-and-play smart light bulbs. Unlock the power of smart lighting with app-controlled LED bulbs that e...
Best Smart Street Lights: Intelligent Street Lighting Systems and Smart City Poles
Best Smart Street Lights: Intelligent Street Lighting Systems and Smart C...
A smart street light is an intelligent outdoor lighting system that is context aware to its environment and is wirelessly networked to support interoperability and sop...
How Does Smart Lighting Work
How Does Smart Lighting Work
Everything you need to know about smart lighting. Experience intelligent, connected solutions that unlock the full energy efficiency potential of LED lighting. Open up...
Does LED Lighting Pose Health Risks—Blue Light Hazard, Circadian Disruption?
Does LED Lighting Pose Health Risks—Blue Light Hazard, Circadian Disrupt...
White LEDs are no more hazardous than other lighting technologies that have the same correlated color temperature (CCT). Exposure to blue-enriched light at the wrong b...
How Do LED Lights Work? A Tricky Technology, A Messy Marketplace
How Do LED Lights Work? A Tricky Technology, A Messy Marketplace
Lighting technology is advancing, light quality is deteriorating. Lack of consumer awareness and absence of quality regulation make LED lighting technology a scapegoat...
IoT Platform Overview: Architecture, Capabilities, Types, Top Cloud Platform Providers
IoT Platform Overview: Architecture, Capabilities, Types, Top Cloud Platf...
IoT platforms facilitate interactions between devices, applications and networks. They orchestrate many of the fundamental aspects that synergistically make an IoT sol...
LED Driver (LED Power Supply): What Is It and How It Works?
LED Driver (LED Power Supply): What Is It and How It Works?
An LED driver is the brain of an LED lighting system. It provides power conversion, load regulation, and downstream component protection. LED drivers are also the inte...
Thermal Management Technologies for LED Lighting Systems
Thermal Management Technologies for LED Lighting Systems
Thermal management is essential for LED luminaires because high junction temperature negatively affects LED performance and reliability. The object of thermal manageme...
Wireless Lighting Control Technology
Wireless Lighting Control Technology
Wire connectivity is an integral part of Internet of Things (IoT) enabled lighting systems. It is the conjunction of wireless networking and automatic lighting control...
Motion Sensors for Occupancy and Intrusion Detection
Motion Sensors for Occupancy and Intrusion Detection
Motion sensors can be used to control lighting or automate the operation of other connected devices. The three most common types of motion sensors used for occupancy a...
Lighting Control Technologies: Dimming LED Lights with PWM, CCR, DALI, DMX, 0-10V
Lighting Control Technologies: Dimming LED Lights with PWM, CCR, DALI, DM...
The importance of LED dimming is beyond what most people would ever imagine. The power of LED lighting can only be unlocked when light fixtures are dimmable.
Color Rendition of Light Sources: Color Rendering Index (CRI) & Beyond (TM-30, CQS, GAI...)
Color Rendition of Light Sources: Color Rendering Index (CRI) & Beyond (T...
The color rendering characteristics of a light source include color fidelity, color discrimination, and color preference. The importance of a light source's color...
Color Temperature of Lighting Products: Wrong CCT Preferences Threaten Human Health
Color Temperature of Lighting Products: Wrong CCT Preferences Threaten Hu...
Color temperature is closely associated with the synchronization of human circadian rhythms to the 24-hour solar cycle. Using a right color temperature helps create at...
Tunable White LED Cylinder Pendants/Downlights Deliver Human Centric Lighting in Perfect Purism
Tunable White LED Cylinder Pendants/Downlights Deliver Human Centric Ligh...
Bring the dynamics of natural light indoors with this surface, pendant or wall mounted LED luminaire which delivers tunable white or dim-to-warm lighting in a striking...
LiFi Technology Supercharges Wireless Communication and IoT Connectivity through LED Lighting
LiFi Technology Supercharges Wireless Communication and IoT Connectivity ...
Integrating LiFi in LED lighting offers intriguing possibilities for wireless communication. LiFi-enabled LED lighting enables more ubiquitous deployment of IoT networks.
Smart LED Light Panels for Cinematography, HD Broadcasting and Digital Photography Lighting
Smart LED Light Panels for Cinematography, HD Broadcasting and Digital Ph...
An app-controllable LED light kit that makes high speed broadcasting and motion picture productions a breeze. The DMX addressable and Wi-Fi enabled light panel offers ...
Twinkly Smart LED String Lights Enrich Christmas/Holiday Lighting Design With Intuitive App Control
Twinkly Smart LED String Lights Enrich Christmas/Holiday Lighting Design ...
An app-controlled RGB LED string light that can be wirelessly operated to create an infinite variety and combination of lighting effects. Twinkly offers an innovative,...
Philips Hue Outdoor Lightstrip: Smart Light Strips Offer App-controlled LED Neon Lighting
Philips Hue Outdoor Lightstrip: Smart Light Strips Offer App-controlled L...
A waterproof flexible light strip developed for use in wet and damp locations. The smart light strip operates on Philips Hue system and offers an array of smart lighti...
OLED Lighting: Redefining Light Quality and Lighting Design
OLED Lighting: Redefining Light Quality and Lighting Design
OLED lighting offers truly unique forms and design flexibility which are highly appealing for lighting designers, manufacturers and consumers. The unique features of O...
Intelligent Street Lighting with Internet of Things (IoT) Connectivity
Intelligent Street Lighting with Internet of Things (IoT) Connectivity
Development in LED technology and Internet of Things (IoT) provides a practical opportunity to combine street lighting and network communication with the flexibility a...


 
Featured Guides
Most Popular
 
Latest Articles
 
Featured Products
 
Home | About Us | Plans & Rates | Contact | Terms | Privacy