LED Tunable Light
LED Lighting continues to offer consumers more than just energy efficiency, and with new types of tunable lighting technology becoming more readily available, there are a variety of additional benefits.
LED Luminaires, with the ability to deliver varying light color, have been on the market since early days of LED lighting, but the colors, controls and capabilities keep improving and their applications continue to grow. The US Office of Energy Efficiency and Renewable Energy states that these technologies are proving to have benefits beyond energy efficiency and may in fact improve environments and conditions in schools, hospitals, residential spaces and more.
Here we explore tunable lighting in general, the areas we are seeing this technology, and why you would want to consider putting tunable lighting in your business.
3 Categories of Color-Tunable Products
Dim to Warm
- These are also referred to as "blackbody dimming" or "incandescent-like" dimming
- These products mimic incandescent or halogen dimming performance. They usually range from 2700K-3000K at full output down to as low as 1800K. The light color becomes increasingly warmer as the products dims.
- These products are often used in places where you want a whiter light in the day, but a warmer light in the evening: restaurants, hotel lobbies and guestrooms, ballrooms, theaters and residential spaces.
- Because dimming is linked to color changing in this type, Dim to Warm products only use one control signal per group of fixtures/luminaires. These can be equipped with a wireless receiver for control by a wireless transmitter.
- A potential issue with these products is that some users want to reduce light output without changing color, and in that case white-tunable may be a better choice.
- These are also referred to as "tunable-white" or "kelvin-changing"
- These products have two sets of phosphor-coated LED primaries; one with a warm-white color (around 2700K) and the second with a cool-white (between 5000k and 6500K).
- By controlling the two different LED's (up or down), you can create a straight line that connects them on a "chromaticity diagram." This is called linear white tuning.
- There are also luminaries that use three or more LEDs, which allows the capability to produce a wider range of color. These do not create a straight line, but follow the blackbody curve, much like the dim to warm version (called nonlinear white tuning). The colors created on the chromaticity diagram are not what you see.
- White tuning is used for a range of reasons, including providing apparent cooling or warming to a room, providing a psychological effect, such as using cool-colored lights to make occupants feel cooler on a hot summers day, or to calm or invigorate students in a classroom.
- These products are often selected when a space undergoes a renovation or interior design remodel and the lighting needs to adjust to a new theme or color palette. White tuning is great in retails, and is also used to simulate daylight or match color of daylight in a windowed lobby, for example, or to assist with behavior control.
- Potential issues include the fact that the control interface can be more complicated. Controlling two separate lights with the same switch, or two different switches, depending on preference, creates for more difficult wiring of the controls versus a fixed color LED.
Full Color Tunable
- These are also known as "spectrally tunable" or "color changing"
- Full color tunable products are just as they sound; full color and full tuning. These are the most versitile of the options, allowing you to completely change the space at any given time (from dim white to bright purple)
- These products usually have three or more different LED primaries that can be individually varied in output to create a mixture of light that is white, a tint of white or a saturated hue.
- The minimum for full-color tuning is three, but full color tunable systems have 4, 5, 6 or even 7 color systems for even more unique colors of individual LED’s.
- You will find these in such applications such a theaters, theme parks, arcades or restaurants.
- Full color tunable requires a more complex control interface, and must be powered separately from the luminaire.
- Potential issues with full color tunable include initial and reprogramming of these controls are hard to handle in-house and require a professional. It is also easy to skew colors and oversaturate or undersaturate a space if not tuned correctly.
What Are The Advantages of Tunable Lighting?
Light regulates our circadian rhythm, effecting our emotional and physical being. As the sun come sup the light levels increase and become cooler, helping us become more awake and active, and as the sun goes down, light levels decrease and become warmer preparing us for sleep. Both the intensity and spectrum of light can be used to stimulate or suppress hormones such as melatonin, impacting our mood, alertness and health. The ability to control interior light to affect the attitude, happiness, effectiveness and productivity of a person or group is an amazing advancement in technology.
Tunable white is often used in schools giving teachers the adjusting light setting for given activities, with a remote or a switch on the wall. Many classroom studies suggest that the color and intensity of light can be modified to calm or invigorate students, or to focus their attention, and even provide a less stressful environment for students, while improving the overall learning environment.
Many school districts are implementing this type of technology in special needs classrooms, replacing the need for the cloth curtain over the light fixture. TRC helped upgrade a small clasroom at McGuire Middle School (Lakeville, MN) to tunable lighting and we have received excellent feedback.
Lighting Controls Association
Tunable light is also being introduced in conference rooms to set the tone of the meeting, from intense to happy hour, in healthcare settings to help with the regulation of biological clocks, and retailers to better showcase colors that pop or better engage customers by adjusting lighting on demand.
You may also see tunable light popping up in Senior Living Facilities, such as this study conducted in Sacramento, CA. The study discusses the variety of products implemented throughout the facility and the variety of color temperatures utilized and their effects.