Circadian / Integrative / Human Centric Lighting

Mr. Glass

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I have a single family home in the US and am seeking to create a circadian lighting solution. Ledvance seemed like the closest thing I could find that may potentially be available in the US in the consumer sector (though I couldn't yet find any vendors that sell it).

Has anyone gone down this rabbit hole/do you have advice about melanopic lighting options with a high estimated daylight illuminance (mEDI) rating? My understanding is that Hue may not meet this criteria.

I'm also considering commercial grade solutions over time, but they're really expensive.

Europe has a variety of options in the consumer segment, but I haven't found much in the US.
 

chillinn

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From a high altitude and without having gone down this rabbit hole, the trick is merely to avoid using lights heavy in the blue spectrum, or with a spike in the blue, within a wide margin before bedtime. Cool color temperature lights have more blue, neutral less, warmer less still. Good luck!
 

Mr. Glass

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From a high altitude and without having gone down this rabbit hole, the trick is merely to avoid using lights heavy in the blue spectrum, or with a spike in the blue, within a wide margin before bedtime. Cool color temperature lights have more blue, neutral less, warmer less still. Good luck!
Thanks for your reply. I'm seeking something a bit for advance than this - Lights I can get in the US that are designed for a high melanopic EDI during the day (250+) and low at night (less than 10). Adjustable color temperature change does not necessarily guarantee daytime circadian impact. Though the reverse is true that cheap blue light at night can disrupt melatonin production.

Here are some examples that are available in Europe, but not in the US:
https://www.kiteo.eu/ (parent company is Lumitech)

The only options I've seen so far in the US is Bios who also licenses their tech to various commercial providers that offer high end lighting that's priced in the tens of thousands:

They also have a limited set of residential products, but it doesn't look like they offer a standard A19 sized light bulb that does both day and night:
 

chillinn

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Just by the depth of understanding and knowledge of what is commercially available, I suspect, at the moment, you are CPF's resident expert on circadian lighting, as all I could think of is suggesting using windows, not lights, during the day, and to retire for the night by astronomical twilight.
 

Mr. Glass

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Just by the depth of understanding and knowledge of what is commercially available, I suspect, at the moment, you are CPF's resident expert on circadian lighting, as all I could think of is suggesting using windows, not lights, during the day, and to retire for the night by astronomical twilight.
Hahaha. Yes, I do try to be near windows during the day and sunlight is best. Do you know of any other sites that may contain folks who've researched this?
 

Mr. Glass

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No, but I just saw this old post in search results.
Interesting post. Just wish they had some US available bulb recommendations. Eventually I may get the f.lux recommended meter


to refine placement and verify efficacy, but first I'm just trying to find bulbs that can hit the proper range and don't have too much flicker, which can supposedly be detected with a standard cellphone camera.
 

LEDphile

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Variable CCT sources that can vary over a wide enough range (at least 2000K to 5000K, ideally up to 6500K) will get you close, especially if they are high CRI - a 90 CRI LED source has an MDER pretty close to 1 across the range of CCTs (slightly above 1 at low CCTs, slightly below 1 at high CCTs). If you want to enhance MDER, you will need to add cyan to the spectrum, although note that simply adding more flux without changing the spectrum will result in the same melanopic response. Reducing melanopic activity can be achieved by reducing flux, and by pushing to even lower CCTs (or even amber or red lighting). None of these approaches require special lamps or fixtures beyond the commonly-available smart bulbs (or even a combination of low CCT lighting in a table lamp and high CCT/high flux lighting in a ceiling fixture).
 

Mr. Glass

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Variable CCT sources that can vary over a wide enough range (at least 2000K to 5000K, ideally up to 6500K) will get you close, especially if they are high CRI - a 90 CRI LED source has an MDER pretty close to 1 across the range of CCTs (slightly above 1 at low CCTs, slightly below 1 at high CCTs). If you want to enhance MDER, you will need to add cyan to the spectrum, although note that simply adding more flux without changing the spectrum will result in the same melanopic response. Reducing melanopic activity can be achieved by reducing flux, and by pushing to even lower CCTs (or even amber or red lighting). None of these approaches require special lamps or fixtures beyond the commonly-available smart bulbs (or even a combination of low CCT lighting in a table lamp and high CCT/high flux lighting in a ceiling fixture).

Thanks for this. Things would be a lot easier if I could just get Philips Hue (which is not off the table for me), but I was under the impression that even their tunable white versions will not have adequate circadian impact. Do you know what the MDER or mEDI rating of Hue is? Searching for this I've come up empty.

Also, I've heard the flicker will inhibit circadian impact. Note that the creator of this video is the owner Vitae Light, which is a competitor to Hue.



 

jtr1962

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Just by the depth of understanding and knowledge of what is commercially available, I suspect, at the moment, you are CPF's resident expert on circadian lighting, as all I could think of is suggesting using windows, not lights, during the day, and to retire for the night by astronomical twilight.
That would be not much after 9 PM in the summers, and around dinner time in the winters. Even most children don't go to sleep that early.
 

jtr1962

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I doubt you're going to find anything in an A19 bulb form factor. What you want to do screams purpose-made LED fixture.

If I had to design something like this, maybe I'd opt for maybe a mix of 2700K and 5000K Nichia Optisolis (98 CRI, minimal blue spike). During the day the 5000K only would be on. As sunset approaches the 2700K would come on at low intensity. The 2700K intensity would go up, while the 5000K intensity would go down, while sunset was occurring. By the time night came, you would have 2700K exclusively. The reverse could happen at sunrise if you have the light on then. The hard part would be synchronizing the light with sunset. Maybe use a GPS chip to get the time/date, and a lookup table of sunrise/sunset times at your latitude.
 

Mr. Glass

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I doubt you're going to find anything in an A19 bulb form factor. What you want to do screams purpose-made LED fixture.

If I had to design something like this, maybe I'd opt for maybe a mix of 2700K and 5000K Nichia Optisolis (98 CRI, minimal blue spike). During the day the 5000K only would be on. As sunset approaches the 2700K would come on at low intensity. The 2700K intensity would go up, while the 5000K intensity would go down, while sunset was occurring. By the time night came, you would have 2700K exclusively. The reverse could happen at sunrise if you have the light on then. The hard part would be synchronizing the light with sunset. Maybe use a GPS chip to get the time/date, and a lookup table of sunrise/sunset times at your latitude.

Changing the CCT in conjcuntion with the sun can be done using the f.lux app and other options in combination with a hub. Vitaelight and Ledvance sun@home (see my links above) offer A19 bulbs that claim to meet circadian criteria, but are only available in Europe at the moment.

Bios lighting makes an A19 bulb that changes CCT,


but it's unclear whether that's still available so I made this post to see if folks here know of other options available in the US.
 

chillinn

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That would be not much after 9 PM in the summers, and around dinner time in the winters. Even most children don't go to sleep that early.

I sure wish there was a point in there somewhere. Are you certain that you have a good idea of what most children do? Is that 51% of children, or higher, like 75% or 90% of children? At any given time, there's over 70 million children in the US, and most of them, obviously, are under the age of 13 and with a recommended bedtime before 9PM. But this is, of course, irrelevant, as OP is not a child. Adults can pretty much do what they want, including sleeping by 9PM if they like and rising at 5AM. There's almost half a million Amish that generally retire by 9:30PM every night. Farmers start work early and often work 12 hour days and longer during harvest. You think they stay up late, in general? Sometimes I stay up all night and won't sleep until the following night. Sometimes I am asleep by sundown. When we make sweeping generalizations and employ bandwagon fallacy, we're almost always incorrect.

Also, not for nothing, it is possible to edit a post to complete a thought. Look for the edit link in blue below your post and to the left, and try it. And that way you're not constantly flooding threads with multiple consecutive comments.
 
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jtr1962

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I sure wish there was a point in there somewhere. Are you certain that you have a good idea of what most children do? Is that 51% of children, or higher, like 75% or 90% of children? At any given time, there's over 70 million children in the US, and most of them, obviously, are under the age of 13 and with a recommended bedtime before 9PM. But this is, of course, irrelevant, as OP is not a child. Adults can pretty much do what they want, including sleeping by 9PM if they like and rising at 5AM. There's almost half a million Amish that generally retire by 9:30PM every night. Farmers start work early and often work 12 hour days and longer during harvest. You think they stay up late, in general? Sometimes I stay up all night and won't sleep until the following night. Sometimes I am asleep by sundown. When we make sweeping generalizations and employ bandwagon fallacy, we're almost always incorrect.

Also, not for nothing, it is possible to edit a post to complete a thought. Look for the edit link in blue below your post and to the left, and try it. And that way you're not constantly flooding threads with multiple consecutive comments.
The point is that it's not a very practical suggestion. Humanity invented artificial lighting exactly so that we can do tasks at times of our own choosing, instead of relying on sunlight. There are varying hours of daylight during the year. Obviously in the winter months your suggestion would result in spending up to 15 hours a day sleeping.

Also, going by your suggestion ~9PM would be the very latest bedtime, and then only in mid summer. The rest of the year it would be much earlier. 9PM might not be a completely outlandish bedtime for young children, but anything much earlier is. I personally recall being up until at least 10 PM by the end of grade school. In high school if I got to bed at midnight it was early. By college try 2 or 3 AM. This was regardless of the time I needed to be up. Just couldn't get to sleep any earlier.

Getting up at 5AM, unless you have to leave super early for work, sounds ridiculous, as does adults going to sleep at 9. Unless of course you're an extreme morning person where such a schedule would seem natural. Or a farmer.

If lots of people have sleep deprivation, it's because start times for school and work have shifted to times which work against the circadian rhythm of the majority. DST makes the problem even worse.


"Our findings provide additional evidence that sleep-wake cycles of teenagers are delayed and support for the idea that social systems should not encourage further sleep deprivation but instead work around physiological needs," says Urbanek.
 

TimMc

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Circadian Stimulus (CS) and Equivalent Melanopic Lux (EML) came up in a recent discussion about the Light Master 4.

I have been using the Opple Light Master 3 to take CCT, CRI and duv measurements when reviewing flashlights.

I wonder if the v4 upgrade with CS and EML measurements would be useful for verifying whether the lights that you purchase for your home actually perform as advertised.
 

chillinn

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Humanity invented artificial lighting exactly so that we can do tasks at times of our own choosing, instead of relying on sunlight.
The invention of artificial lighting makes sleeping early impractical? It doesn't get any more practical than retiring and rising with the setting and rising of the sun. A time on the clock is entirely incidental, and if you didn't have a clock or artificial lighting, that's precisely what you'd do. I guess it's just too bad you have no control over your artificial lighting and are compelled to stay up later.
 

Mr. Glass

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Circadian Stimulus (CS) and Equivalent Melanopic Lux (EML) came up in a recent discussion about the Light Master 4.

I have been using the Opple Light Master 3 to take CCT, CRI and duv measurements when reviewing flashlights.

I wonder if the v4 upgrade with CS and EML measurements would be useful for verifying whether the lights that you purchase for your home actually perform as advertised.

Thanks for sharing. Just bought one to try. This looks like a much more affordable option than the f.lux meter setup so I'll at least give it a go since it's returnable.

For anyone who sees this, I'm still seeking options for consumer grade circadian lighting in the US in addition to the Bios link I mentioned above. The Ledvance sun@home options using SunLike COB is the closest I've come, but not yet available in the US.
 

KITROBASKIN

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Mr. Glass,
Thank you for bringing this up. Please keep us updated.

Like others are thinking, though, it seems having different light sources for different times of the day would be simpler and much more cost effective. Yet there is some appeal to integrating the illumination experience desired.

Of course, having the term 'human centric lighting' in this thread title will elicit some derision and not be helpful to those who get triggered by such 'holier than thou' pronouncements, perhaps lessening the adoption of this technology.

If the objective is to get more cost effective lighting that automatically alters color temperature here in the USA, then a more inclusive rhetoric is advised.

But then again I could be barking up a tree that the squirrel has long vacated.
 
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LEDphile

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The Philips Hue system can be programmed with time-of-day events (including ones tied to sunrise/sunset), although you may need third-party apps to do it. And with a bit of paying attention to what your settings look like, you can get reasonable circadian performance. A mix of the tunable-white bulbs and the full color bulbs will give you some options to play with spectrum as well, while still keeping the cost lower than if you went all-in on color bulbs everywhere. Not saying it's the best option out there, but it's certainly an option that can work and is readily available in the US.
 
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