Hi everyone,

My living room is north-facing, and outside of summer it’s quite challenging — I’m constantly missing natural daylight. The room is about 5.5 × 4 m with a 3.2 m ceiling.

Does anyone have experience with human-centric lighting (HCL)? For example, what lights or LED strips work well?

From what I understand, it should be properly designed — starting with the required lux levels, then choosing LED strips that best mimic daylight, and also considering cooling and power supply for the setup.

Any advice or real-world experience would be really appreciated.

Thank you!

 

Hi everyone,

My living room is north-facing, and outside of summer it’s quite challenging — I’m constantly missing natural daylight. The room is about 5.5 × 4 m with a 3.2 m ceiling.

Does anyone have experience with human-centric lighting (HCL)? For example, what lights or LED strips work well?

From what I understand, it should be properly designed — starting with the required lux levels, then choosing LED strips that best mimic daylight, and also considering cooling and power supply for the setup.

Any advice or real-world experience would be really appreciated.

Thank you!

I watched a video years ago where a guy repurposed old LED TV screens as skylights. The effect was pretty neat.

Edit:

 

the old dayz are gone

there are led strips etc... which can help here. the question is - know how to design all above mentioned

 

5500K to 6000K is considered daylight. Below is a link to Walmart. They sell "Happy Lights" designed to lift ones mood by simulating natural daylight. This one is adjustable.
https://www.walmart.com/ip/Light-Th...unction-Sun-Lamp-Full-Spectrum-Ho/19958107133

 

The honest producers of LED lighting usually are able to provide information about the spectrol elements provided by their products. That is often referred to as the color temperature. That information is usually available on product data sheets. (Often not available from some sellers.)

 

Many led strips on line that allow colour temperature to be set by user .
Even the led lights in our bathroom, had switches in them to select colour temperature.
When I was in Norway / Finland in the winter , 24/7 dark , we had rooms with very bright lights we all went to for lunch. It seemed to help

 

i think its not about the temperature of the light, its also about its characteristics ie if it can simulate they daylight its spectral analysys

https://www.led-professional.com/al...pectrum-improves-learning-and-memory-function


thanks

 

fyi.
light "colour" is its characteristic
when it comes to "white light" , there are a range whites , identified by their " temprature" .
this goes back to tungston filiments , where at different currents, they had different tempratures , produced different colour .
https://www.ledlightexpert.com/understanding_led_light_color_temperatures_ep_79

 

@drjohsmith i dont know, but that spectral analysys close to daylight is also important parameter, isnt it?

 

@drjohsmith i dont know, but that spectral analysys close to daylight is also important parameter, isnt it?

why ?

 

The less confusing term that is used is "color temperature." That made more sense in the past when the only way toproduce light was to heat something until it glowed. Then luminescence was discovered, which seldom involves much heat. NOW LEDs schanged everything. BUT "color temperature" is still a useful concept.

 

hello, so you are saying that Spectrogram results of the light produced by led stripe is not important?

 

hello, so you are saying that Spectrogram results of the light produced by led stripe is not important?

a spectrogram, is just a plot of frequencies against amplitude
https://en.wikipedia.org/wiki/Spectrogram

so your asking, is the frequency of the light used important!

clearly , yes , thats why your looking for a light !

maybe, your worried about "every" frequency in daylight not being present in LED lights , being specific frequencies.

Thats more of a physiological / medical question, not an engineering one.
we can say that a quick survey of the market , shows LED lights used for this task.

Having spent a few weeks in land of eternal night
I can say that the goverment provided light room, was bright, and had a blue hugh to the light .
it also had a UV component , and we were all exposing a lot of skin.

so, what do you want to do ?
make your own?
whats your experiance ?
you seem to be asking basic questions about powersupplies and cooling !
In my experiance , unless you have the parts to make a safe design, remember this is likely to be mains powered and skin liable to be near, then purchasing a off the shelf unit is advised.

for ideas try here
https://www.trilux.com/gb/service/knowledge/human-centric-lighting/

 

@drjohsmith
thanks you summarized it pretty nice.


Well, my flat is north-facing and I also work from home, so all I want to achieve is to have the option of LED lighting that mimics daylight as closely as possible, so that I can generally feel good in the room.



thanks

 

For example, what lights or LED strips work well?

I have a space significantly smaller than your room from which I work, and I have a pair of 200W LED bay lights turned up towards the ceiling, so I never see the surface of the lights. It's very uniform diffused lighting. They are 5000K and 150lm/w. So it's about 60,000 lumens. That's just enough to call it well lit.

All commercially sold "mood" lamps are laughable under-powered. Maybe 20-30W.

 

Since the color spectrum of "daylight" can be quite well measured, assembling a collection of light emitters that come close to matching that spectrum should be quite possible. BUT it will probably NOT be simple.

 

Since the color spectrum of "daylight" can be quite well measured, assembling a collection of light emitters that come close to matching that spectrum should be quite possible. BUT it will probably NOT be simple.

i was expecting that led manufacturer will measure their led source and sell it ... so once installed you can get closed to that. maybe i am wrong.

i cant recall the name of that seller/producer, once find out will provide here.

 

Genuine HCL accounts for the diurnal cycle and the varying color temperature of the ambient light from the sun from morning to night. A single color temperature can't capture this.

Additionally, since the sun is effectively an incandescent light source, simulating it with LEDs requires clever use of multiple emitters and carefully designed phosphors. The spectrum of a white LED not designed for color and focusing on output numbers will be much too blue.

Even the lower color temperature LEDs will be blue-biased if it is not intentionally designed out.

Buy one of these, they are cheap and surprisingly accurate. It will help you visualize what is actually happening with various light sources. It can be very enlightening (I refuse to say if any pun was intended.)

​

 

@ya'akov
thanks but i think i have to rather find what led and figure out how to design it properly.

thx!

 

I have not come across that term," human-centric lighting (HCL) " previously. Since daylight (sunlight) also affects plants, animals, and even lakes and oceans, that term seems to me to be a poor choice. "Natural Daylight" or "Natural SUNLIGHT" would be better descriptors.