LED ceiling coving light capable of 2500lx and full RGB/timer programmable capability

Twinbee · Mar 11, 2015

To help treat SAD, to help sleep better, and for dramatic lighting possibilities, I'd like to buy LED strip lighting for the coving (skirting board for the ceiling). Something like this.

Thing is, I want full programmable RGB LEDs for deep orange at night (say around 5-50 lux) and a brightness of at least 2500 lux (preferably 10000 lux) with a colour temp of 6000K during the daytime (especially for the winter months), with a smooth transition from one to the other over a period of about an hour around sunset. My room is around 3 metre squared, so I would need 12 metres of strip LED lighting to cover it. I'm prepared to pay up to £1000 to get the best possible LEDs (200 lumens / watt if possible!!). The LEDs should be able to be programmed separately so that graduations from say, yellow to red across the ceiling are possible. I've seen such strip lighting on Youtube etc., but I'm interested in a brightness around the 5000 lux level (at normal sitting positions with in the room) to help combat SAD, and to help 'lift' the room generally.

Any ideas on the state of the tech to achieve this goal?

CoveAxe · Mar 11, 2015

I'm prepared to pay up to £1000 to get the best possible LEDs (200 lumens / watt if possible!!).

200 lm/W is not going to be possible. White LEDs that are 200 lm/W have two problems: They are insanely expensive as LEDs go (The best price I could find in a quick search is $3/LED in quantities of thousands), and they must be run at very low currents to get that level of efficiency (so you're going to need a lot of them). Colored LEDs have much worse efficiency. Since strip lighting is more for hobbyists or small projects, there are no commercially high-efficiency strip lights as far as I know.

The LEDs should be able to be programmed separately so that graduations from say, yellow to red across the ceiling are possible. I've seen such strip lighting on Youtube etc., but I'm interested in a brightness around the 5000 lux level (at normal sitting positions with in the room) to help combat SAD, and to help 'lift' the room generally.

My quick search tells me you have a choice: High efficiency/brightness, or smooth graduation in color. Not both. Here's a strip light that will do color chasing, which I believe is what you are essentially looking for, but the efficiency is 37 lumens/W (also doesn't seem to be very bright either). There's also no white LED in it so you will need to color mix to get the white you want, but at the cost of more power. There's this one that has much better efficiency (~75 lm/W), but you can't do graduations in color unless you split them up and use a bunch of separate controllers.

nickelflipper · Mar 11, 2015

Soffit lighting is going to provide really poor general lighting, just think about the reflective angle from the source. That strategy is only going to provide just what you see in the link, which is a peripheral Mood lighting. Seen plenty of it using linear fluorescent tube lighting.

Having individual LED control sounds pretty cool, but when you consider P = IV, the amps go way up with a low voltage (parallel) solution . Also, the control wiring and circuitry becomes much more complicated. They make individual IC's that would help like the TLC 5940 and the WS2801, but they are usually associated with low power LED's. Here is an example of the WS2801 low power strip link.

If I were considering something like this, I would divide the room/ceiling into fourths, and look at running 3 strings of Cree XM-L color LEDs. Creating the fixture, LED spacing, heatsinking, diffusion material, wiring, etc. would be a real challenge.

Twinbee · Mar 11, 2015

Thanks for the info. I'm prepared to compromise on the lm/W and programmability (though I'd still need a timer and any brightness or colour).

CoveAxea, that latter 75lm/W link unfortunately only gives off 600 lumen. To get the amount of lux I'm looking for, I'd need something more like 10,000 or even 100,000 lumen. That sounds like a lofty target, but if a relatively small floodlight can manage 7500 lumen (100 watt at 75 lumen per watt), then I don't see why something with many more LEDs can't manage something much greater than even that.

Nickelflipper: Cove lighting is fine for general purpose lighting, especially if you have the ledge around or more than 50cm from the ceiling. See Wikipedia for more info: http://en.wikipedia.org/wiki/Cove_lighting

CoveAxe · Mar 11, 2015

Twinbee said:
CoveAxea, that latter 75lm/W link unfortunately only gives off 600 lumen.

Whoops, posted the wrong link for that one. I actually meant this one. It's 270 lumens/ft. Doing the math, that would give you about 10,000 lumens if you went around 12 meters. The strip lighting is thin enough that you should be able to go around several times if more is needed, assuming that heat and power are properly taken care of.

I'd need something more like 10,000 or even 100,000 lumen

100,000 lumen would be like having 62 100W light bulbs in one room. That is going to be uncomfortably bright indoors.

Twinbee · Mar 11, 2015

Aha that looks a lot better - just a shame it doesn't have a timer. And I'm not sure if it allows you to change the saturation of the colour (e.g: between red and white to make a pale red). I'll bear it in mind though thanks, or at least keep it as a yardstick to compare with future products.

100,000 lumen would be like having 62 100W light bulbs in one room. That is going to be uncomfortably bright indoors.

Initially on reading that, I thought my 100,000 lumen guess was OTT. But after doing the math, it appears to result in only 2500 lux that would fall on each surface in my room. (Apparently 2500 lux is the minimum needed to combat SAD). Bear in mind, the 2500 lux will come from only indirect illumination, not direct. Also consider the sun offers up to 100,000 lux, so it's 40x dimmer than a sunny day! (Okay granted, not all of outside is painted white, but still...)

Just check my logic and see if I'm right:

My room = 2.4m x 2.8m x 3m
So that's 44.64 square metres of surface area.
Required lux is 2500.
Using this calc tells me I need 112500 lumen to produce 2500 lux.

Internal reflections probably increase that figure, but only to (I'm guessing) about 5000 lux at most. I'd only use it during the daytime as well - never at night.

So unfortunately, that strip light product will only produce around 250 lux, again, if I'm not mistaken. Ten times less than I need.

CoveAxe · Mar 11, 2015

Aha that looks a lot better - just a shame it doesn't have a timer. And I'm not sure if it allows you to change the saturation of the colour (e.g: between red and white to make a pale red).

It's fully controllable with the optional controller they sell. It apparently has an app that lets you control it from a phone or tablet. It shouldn't be hard to write a simple script that would tell it to do whatever color change routine you want and time it. (Disclaimer: I've never used this product, I'm just going off what the website says. I've bought from superbrightleds.com before though and they do sell quality products).

it appears to result in only 2500 lux that would fall on each surface in my room

Yeah, I think you're right. I didn't think about that. I guess you may need to augment the light from top with other bulbs in the room?

Or another thing you could do is buy a few of these or something similar and get much more output. You will need to build a really good cooling system for it though, likely water or oil cooled.

nickelflipper · Mar 12, 2015

Twinbee said:
Nickelflipper: Cove lighting is fine for general purpose lighting, especially if you have the ledge around or more than 50cm from the ceiling. See Wikipedia for more info: http://en.wikipedia.org/wiki/Cove_lighting

Never tried a brightly lit room with only indirect lighting, never seen it, always involved down lighting of some sort. Sure bedrooms, hallways and the like can be lit with sconces (uplighting), but your not looking for, or not needing bright light in those areas. To think putting a light source up in the corners of a ceiling is somehow going to approach the efficiency of down lighting defies all logic.

Going back to my XML color suggestion; Qty 30 x 100 lumens (cool white @350mA) x 2.5 (drive at one amp) gets you only 7500 lumens. In addition, if you use the RGB LEDS to mix a white then you might double that? So still short by your calculations.

Twinbee · Mar 12, 2015

Thanks very much.

For now I'll stick with the 100W LED floodlight and point it in the direction of the wall I'm facing for around (I'm hoping as I still need to fit the plug) 500-1000 lux. Not as much as I hoped for, but combined with the SAD light I also have (10000 claimed lux, but from my sitting position, only around 700 lux, since my desk setup won't allow it too close), it's getting there.

I'll keep in mind the links and info you've given me - thanks again. I look forward to the extremely general purpose lighting when I combine presumably-mega powerful LEDs of the future with coving-style lighting!

Twinbee · Mar 12, 2015

To think putting a light source up in the corners of a ceiling is somehow going to approach the efficiency of down lighting defies all logic.

Yes, it's less efficient, but you get a better quality of light in many people's opinion. Less shadows, more even distribution, and no glaring point sources. To me, that's worth the drop in lux. I suppose it's similar to surround sound versus stereo.

nickelflipper · Mar 12, 2015

Twinbee said:
Yes, it's less efficient, but you get a better quality of light in many people's opinion. Less shadows, more even distribution, and no glaring point sources. To me, that's worth the drop in lux. I suppose it's similar to surround sound versus stereo.

Oh, I agree about the diffusion aspect of uplighting, a nice soft even glow is really nice. In the next couple of months I will be getting around to making a 4 channel, 4x analog pots, 4x4 7segment display, XM-L color LED controller. Will be incorporating an encoder as a color wheel of sorts, and use the encoder switch to change the tint.

Twinbee · Mar 12, 2015

Good stuff, sounds advanced! Going back to your earlier comment, you're right about indirect lighting being (very) rare for a brightly lit room. I bet it would look unusual and really nice though. Also, to have a low lumen array of deep oranges, and yellowey-oranges along with subtle white-ish versions of those would be really nice for the evening/night too. Too bright at that stage (or even average room brightness that people usually have!) and apparently the production of melatonin is reduced affecting the sleep cycle.

SemiMan · Mar 14, 2015

HOLD THE PRESSES --- OR THE LEDs .. or better yet your wallet!

The problem with picking facts off the internet and/or items that related to cross-disciplinary science is they are usually posted by people who don't really understand the underlying science and/or the underlying technology they are dealing with. SAD and lighting to deal with it is one of those cases.

The 10,000 and 2,500 lux numbers often bandied around are just that, bandied, and are rarely correlated to a light source as the people who keep pushing those number have no clue where they came from.

Please read this study before continuing. There are others like it, but this should start you off on the right path.

Semiman

http://www.optimalhealthpartner.com/A_Archive/Anderson_LuxVsWavelength.pdf

Twinbee · Mar 15, 2015

Ooooh, I'm up for a challenge. I'll read that, and see if I can find some decent papers with any claims to the contrary (I'm sure I did originally, but.....).

Either way, I'll have learnt something! I'll post back soon.

SemiMan · Mar 15, 2015

Be careful of the dates on the papers that you read. Anything in the last 5 years should more closely follow the link that I sent. The mechanism has only been understood for about 10 years and well for only 5. iPRG cells have only been characterized in the last 10 years. One could argue that cranking your monitor, smart phone screen, tablet, etc. and looking at it first thing in the morning will give you a significant "kick" as it highly stimulates the cells that regulate circadian rhythm.

Semiman

Twinbee · Mar 16, 2015

If that paper is right, and blue levels can be much lower (100 lux or so) to treat depression, it may be worth making our screens more blue during the day. (I've been working on an app to do *just* that).

Also, the two lights I have now (LED floodlight and SAD lamp) make the room 1000 lux, so that's more than enough (if that paper is right).

CoveAxe · Mar 16, 2015

Twinbee said:
If that paper is right, and blue levels can be much lower (100 lux or so) to treat depression, it may be worth making our screens more blue during the day. (I've been working on an app to do *just* that)

Someone has already done this.

mds82 · Mar 16, 2015

I have been working on the same type of project myself for the my master bedroom whcih is 14x17 feet. We recently just vaulted the ceilings and have an inside tray ceiling. I also wanted to have an adjustable color feature but found that it was a bit too complex and expensive for what i was looking to accomplsh. It could very easily be done, but would require not too much work.

Here is the setup i went with in the end.
- 24 Samsung Light bars: http://www.digikey.com/product-detail/en/0/1510-1138-ND 3000K , 132 Lm/W.
---these have a forward voltage of 24 V dc and are dimmable

- 4 Recom RACT-20-350 US drivers. http://www.digikey.com/product-detail/en/0/945-1630-ND . TRIAC dimmable

The way its hooked up is 1 driver to 3 parallel strings of 2 light bars in series. the light bars fit perfect around the room and then its hooked up to 1 Lutron Maestro digital dimmer. Works perfectly and the color on them is a very nice 3000K.

If you are looking to adjust the color you can to the same thing, but have 2 full setups, 1 @ 3000K, 1 @ 6500K, each hooked up to its own dimmer switch. This way you can adjust the mix of color temperatures

LED ceiling coving light capable of 2500lx and full RGB/timer programmable capability

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