Adaptive lighting – what the heck is it?

Natural circadian rhythms

Body rhythms


In the last few years there has been a lot of interest emerging in how lights and adaptive lighting affect us.

Scientists believe our bodies are heavily influenced by our daily circadian rhythm. A 24-hour cycle of sleeping and waking that regulates many of the conscious and autonomic functions in our body.

Lighting is an important part of this cycle. For most of us that live in time zones with daily savings, think about how you feel when you wake up and whether it is still dark or the sun has already risen.

Similarly, think about the end of day/evening and how the late summer sunset or early winter darkness influences your desire mood or behavoir.
 

The Zen of lighting

I explained previously how modern LED lighting is not truly white but has a color tone which is measured in the Kelvin scale as “degrees K”.

Warm white is approximately 3000K, natural white is 3500K, cool white is 4000K, and daylight is 5000K.

Lighting color temperature
What is the difference between cool white, warm white, and daylight color temperatures?

Warm lighting has a yellow / amber tone, natural or cool white tends to have a neutral tone, and daylight has a blueish tone.

There is no one ideal or perfect tone for light. The right tone depends on many things including what we are doing, the time of day, and personal preference.

Conventional wisdom says early morning and evening times we prefer the soft relaxing amber tone of warm lighting.

When studying or working on focused projects, daylight is best, and for general use the rest of the day natural / cool white strikes the right balance between the two.
 

A paradox of choice


Do you have to climb ladders and swap out lightbulbs three or more times per day to benefit from adaptive lighting?

Obviously this isn’t feasible, so how to choose? Optimize for relaxation, work, or compromise in between?

It feels like a no-win situation: no matter what we choose, it will only be ideal for a portion of the day.

This is a classic “first world problem” of being spoiled by having too many options instead of none.

Just a few years ago there simply wasn’t a choice anyway. Our lightbulbs were yellow or amber in tone and could not be adjusted or replaced.

The introduction of fluorescent and other specialty lighting has offered some choices, but the vast majority of homes still use warm tone lighting and don’t even think about it.
 

The magic of adjustable lighting


Technology to the rescue! We now have LED lights that are dimmable and adjustable. The color tone of your adaptive lighting can be instantly changed from warm yellow to neutral white and all the way to daylight.

It’s actually simpler than you might think. LEDs themselves are manufactured as either yellow or blue tone light emitters. The LED lightbulb has a lot of individual LEDs underneath a frosted plastic or glass diffuser.

LEDs with adjustable color tone have an equal number of yellow and blue LED elements and dimming circuitry to adjust the light output in any combination.

Blending different intensities of yellow and blue LEDs mixes the light to allow setting any color tone from pure yellow to pure blue and anything in between.
 

Swapping an app for a ladder


With so much control over color tone available, an app is a convenient way control it.

Some lighting apps have simple choices such as “warm”, “cool”, and “daylight”, while others give you on-screen dials or buttons to set any color tone you want.

Prefer 3160K during the day and 2580K at night for your lights? No problem. Just grab the app and dial it in.

Many smart lighting companies like Philips and Wyze, and others offer adjustable color tone LED lights.

This feature is often called tunable lighting. Just understand the difference between tunable white lights and colored lights.

It certainly is a lot more convenient than climbing a ladder and swapping lightbulbs. (Let’s face it – nobody would ever do that.)
 

Colored LEDs may or may not be tunable


Many colored LED lights do a rough approximation of tunable white tones by adjusting the red, green, and blue LEDs.

Tunable white LEDs have both yellow and blue LEDs that are mixed for multiple shades of white output only.

If you like colored LED lights, look for the newer RGBW style. The “W” at the end means it has tunable white capability in addition to the color changing red, green, blue.
 

Automation to the rescue


Interactive control is ok, but changing color tones of lights throughout the day is definitely the “poster boy” for home automation.

Whether you want to keep it simple and have warm lighting in the morning and evening, and neutral or daylight lighting during the work day or a more sophisticated scheme, automation is the way to go.

Apple itself has gotten into the game in the latest update to Apple’s HomeKit smarthome system.

Of course, they have to put their own twist on it, as usual. So Apple calls it adaptive lighting, but it is the same thing.

I want to mention that fully automated tunable lighting is new, but not brand new.

Commercial and residential solutions from companies like Lutron Ketra have been available for several years, but bring a wheelbarrow of cash for those.

Robert

Automation technologist and problem solver

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