Tunable-White Lighting: Adjusting LED Color Temperature that is Perfect for You

Tunable-white lighting is a popular trend in both commercial and residential lighting. Thanks to the extensive photo-biological research done by numerous university and scientific departments, we now know more about the way humans function than ever before. LED developers and the community alike have obviously taken an interest in how we as humans interact with the light around us. The scientific findings support the need for a tunable white technology and fortunately LEDs or light-emitting-diodes are the most practical way to do so.

What is Tunable White Lighting
Tunable white light is a technology defined as the ability to control a light source’s color temperature output. You may hear many other terms referring to tunable white LEDs as well: custom temperature, dim to warm, dynamic/hybrid white, or variable white lighting.

Tunable white lighting is created by manufacturing the light source with LEDs of different color temperatures. Combining this with a remote control or using an external control system will allow the user to select their desired white color temperature and change it in real time.

QUICK CATCH-UP – So what is color temperature or CCT?
Say you go over to Home Depot to replace that bulb that went out in the storage closet. Once you find the bulbs, those on the shelf will be classified using many different terms: warm or cool, daylight or natural, bright or soft whites. These names are used to describe the color temperatures that are emitted from the light. These names can be all over the board and are mainly used for marketing purposes. The color of white can actually be quantified using the correlated color temperature (CCT).

CCT is the color temperature of light, measured in degrees Kelvin (K). Temperature rating of a light directly correlates to how the light will look to us. Most LEDs are found within the 2700K-6500K range. Lower temperatures in that range 2700-3000K are known as “warm white” lighting. Warm white looks more orange and/or yellow – like what you would come to expect from a traditional halogen or incandescent bulb. As the degrees Kelvin increases, the color will change from yellow to yellowish white to natural white (4000K) and then to a white with a cooler, almost blue hue (6500K), which is known as cool white.

Tunable White = Color Mixing
With LED lighting the term RGB has become common for color-changing lights. These lights use red, green and blue LEDs to color mix and deliver colors across the whole spectrum. Tunable whites work in this same way, just using varying white color temperatures in order to control the light from a warm to cool tone.

Much like other lighting technologies, there are many levels of quality and sophistication involved in tunable-white lighting systems. It is important to understand the requirements from the lighting but also what other systems provide over the other.

Simple Tunable White Systems – Dual Channel LEDs
The simplest of white tuning systems will use a mix of warm and cool white LEDs and cross-dim between the two. Typically there will be a channel of LEDs @ 2700K with the other channel housing LEDs closer to 6000-65000K. These diodes are typically tightly packed together with some sort of diffuser laid over them to aid in color mixing as the light passes through. This is a safe and simple method of tunable white lighting but it is more for a basic market and doesn’t provide the most quality light across the spectrum.

Higher Quality Multi-Chip Systems – Mixing at the Chip Level
More and more tunable lights are using ‘multi-chips’ which use several tiny LED chips combined into the same module. This means that the color mixing occurs right at the module itself before even leaving the source. The smaller sizes allow for these tunable white diodes to be packed into downlight and strip light technology. These multi-chip systems have a higher performance specification than the alternating dual channel LED strips.

Color Rendering – Quality that MATTERS!
One of the bigger fusses in the lighting world are how white light presents surface colors. Quality color rendering is extremely important, regardless of light source, and tunable whites are not exempt from this issue. Many manufacturers will advertise great performance at their extremes but the colors in between are not mixed well.

It is important to look for manufacturers who look to keep color quality at the highest no matter what part of the spectrum they are at. Industry leaders are beginning to work with tunable white lighting to mimic the sunlight. This involves making sure CCT follows the blackbody line as closely as possible. Groundbreaking technology is currently being worked on to introduce a green light into a tunable system so that it corrects the CCT to stay right along the Blackbody Line. In general, the greater number of channels in a tunable system, the better colors will look when underneath them.

The Blackbody line (BBL) is based on the color a dark iron metal glows when heated up to that temperature. LEDs are binned according to this line and you want to stay as close to the line as possible. This is why LEDdynamics is implementing extra channels of lights to keep the light output perfectly along this curve.

Know your Range – Different Color Temperatures
Always pay attention to the range of whites that a light is offering. Some systems offer a wide natural ‘circadian rhythm’ range that shifts from candlelight to daylight whereas others operate in a much smaller range like 2700-4000K. Smaller range lights are more for decorative purposes whereas the full range, natural lights are more made to help people take advantage of the benefits below.

What are the Benefits of Tunable White Lighting?
There are various reasons you may want to change the lighting in your home, office or commercial facility. With the increase in ways to control lighting, many have come to expect the option to change lighting to some extent. Not only is this convenient, it is also beneficial in some key areas:

Your Health – Circadian Rhythm & Lighting
Increased Productivity
Improved Design
Control Circadian Rhythm through Light Manipulation

Circadian Rhythm is your body’s clock. Our body’s naturally know when to wake up and when to sleep. Throughout the day, bodies are supposed to have a natural rhythm that guides attention, sleeping and eating patterns. Studies of this pattern have shown that intensity, timing, duration and wavelength of light can affect the biological clock of humans.

This rhythm can be easily interrupted now that so many things around us have lights. Hear about all those studies about how looking at your phone before bed is bad for sleep? Yea, that is about circadian rhythm…the bright cool white in your face right before bed, not good for that rhythm. Disruptions in this rhythm can result in many health issues and sleep disorders.

NOTE – It has been found that CCTs above 5500K can disrupt our circadian rhythm by keeping us up when we should naturally be sleeping. That is why phone, computer and tv screens have started to implement night mode that gives off a warmer hue. Utilize this as much as possible!

Our bodies are more alert and awake in brighter, cooler lights and much more calm and relaxed at warmer white. This has to do with the natural light during a day. Mornings start at warmer color temperatures and then increase to 6500K around noon, before decreasing back to warm white before going to the dark of night.

Tunable white LED lighting allows us to stick to our natural circadian rhythm by giving us that range of lighting in either our homes or workplace. During the day you can have 6000K to remain alert and productive and when you are ready to relax for the night you can decrease CCT to closer to 3000K. This helps naturally release the melatonin to help you sleep.

On top of preventing health issues, tunable white LED lighting can help regain healthy habits and normality when you are not able to be outside. Many hospitals and schools have started to utilize this for in-patient rooms or classrooms and have found some interesting things.

Cool White Light Warm White Light
– Increases healthy appetite – Lower Hormone Levels
– Increases body temperature – Calms the body
– Increases heart rate – Allows for better rest and healing
– Increases cognitive function
Increased Productivity
Working under the right lighting actually helps us work diligently and increases our productivity. Having the ability to tune lights according to the needs or moods of the room has a definite impact and can help in many situations.

Research has found that many different environments can benefit by keeping people more alert with cooler lighting and changing to warmer lights in the evening or when they need people to relax. Below are some places that take advantage of tunable white lighting:

Resident Homes
Schools
Hospitals
Healthcare Facilities
Retail Stores
Offices
Gyms
Warehouses
Importance in Design
Lighting is just as important in a space as the wood, structure and paint. Light helps liven or dull down a space and is a main factor in how we feel about a space whether we realize it or not.

Tunable white lighting will soon be expected in most places and tunable white lighting can greatly enhance many aspects of the building and the experience of anyone who enters. Adjustable CCT will allow you to tailor the experience of those entering your space and leave them with a positive experience. Now a space will not be tied down to one overall feeling from light but it will be able to give off ranges of emotions and alertness depending on what the owner wants of it.

Taking Advantage of Adjusting – How to Control Tunable Lighting
In order to take advantage of the tunable lighting, there needs to be a control system in place. This is where systems can alter in their quality and complexity as well.

The simplest solutions use manual control to alter the white outputs. Expect to have a wall-mounted panel or a remote control that enables you to adjust the color of the light as well as brightness. There is nothing scientific about this type of control, it does not mimic daylight but rather allows for personal preference which is nice but will not always allow you to take advantage of completely perfect light output.

More complex control strategies are designed to manipulate the circadian rhythm of room occupants. This basically means the settings are programmed into the control architecture of the building itself. Shifts in color temperature and light level can be pre-set on a schedule or instigated by a manual over-ride. This method is what is needed in order to fully take advantage of the benefits discussed above. The PERFEKTLIGHT from LEDdynamics is working to make a near perfect replication of natural light. This could have huge benefits for many different buildings and organizations.

Get started with Tunable White Strips from LEDSupply
Tunable white lighting is on the rise as the technology becomes more readily available and we continue to see the added benefits to having dynamic white lighting in our home and work areas. LEDSupply has recently added a couple new LED light strips that offer you full control over your white lights.

Tunable White COB LED Flex Strips
Our newest LED Flex strip is the first tunable white LED available from LEDSupply. This COB LED Flex strip packs 608 flip chip LEDs per Meter to achieve smooth and consistent color mixing from 2700-6500K. The alternating LEDs are packed so tightly that the color mixing under the yellow phosphor is extremely high quality for a 2-channel tunable system.

The light strip takes 24VDC input and works in tandem with our Tunable White LED controller. This touch control will tune your whites and brightness levels at the touch of your finger.

Checkout the Tunable White COB Strip!
LuxDrive’s Dynamic Tunable White LED Strip Light
United States based LuxDrive has created an awesome rigid strip light that features 24 Nichia 2-in-1 tunable diodes per 1′ strip section. This is your top of the line color tuning strip light that offers smooth control from 2700K to 6500K.

The strip features easy polk-home connectors that are ideal for 20-22 AWG stranded wire. The whites are tuned and dimmed with (2) 0-10V inputs: one for dimming and one for fully adjustable CCT. This strip can be connected up to 20 at a time and will give you premium color tuning that you will not get from your standard flex strip.