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Indirect lighting with LED strips

kyle_r | Posted in General Questions on

I’ve seen several members mention using LED strips for indirect lighting. I’m curious how others are actually installing the strips. Integrated into crown molding? Can you light an entire room with this method? Are you also still installing standard ceiling fixtures in rooms with the indirect LED strips?

Thank you in advance for the insight!

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Replies

  1. yesimon | | #1

    You might be thinking of "cove lighting". While you can light entire rooms purely using indirect LED strips, I don't think it's a good idea. The system-level efficiency of an indirect LED strip is much lower compared to standard LED ceiling lights or bulbs. Use LED strips as accent lighting to complement primary light sources.

    1. jollygreenshortguy | | #5

      I find the LED ceiling lights to be extraordinarily glaring. Most of the fixtures being offered in the big box stores are awful in that respect. Cove lighting offers much better ambient light, for low to moderate lighting levels.
      My approach to designing artificial lighting in a home is to opt for hidden light fixtures to provide moderate light levels. The only locations where we really need more than that can be handled with task lights. These would typically be places were people read or on a kitchen countertop for food preparation.
      That said, the first thing to do is take full advantage of natural daylight.

  2. Expert Member
    Akos | | #2

    I have exposed collar ties in the living space, a collar tie on each side of the rafter so an 1.5" space between them. I got aluminum coil stock bent into a hat shape that sits on top between, the LED strip is installed into these and light the ceiling. In section of my clerestory window sill trim I also installed standard LED extrusion with strips which also light the ceiling.

    Besides the task lighting and accent lighting this is the only light source in the living space.

    With a flat ceiling there are a number of profiles you can use both mud in and surface mount. Coffered ceilings, crown moldings and up lights above cabinets are good location. This is a fine line to walk though as it can look gaudy if overdone. The key is that the lighting should not be noticeable at all. This is a pretty nice install although not a flat ceiling:

    https://static.dezeen.com/uploads/2017/05/cambridge-house-interior-renovation-corten-steel-annex-massachusetts-american-house-residential-stern-mcaffery_dezeen_15.jpg

    A couple of things to watch for. Almost any LED strip off your favorite online marketplace is garbage. I've tried a bunch, every spec is off, never meets the watts/meter, color temperature all over the place, CRI way off and no or fake UL certification. You want to get stuff from architectural suppliers, they won't be cheap but will also work.

    I've also had a very hard time finding low flicker drivers. Almost all the constant voltage ones have a pretty big 120Hz ripple, the worst offenders are the magnetic drivers, these should never be used for any indoor lighting. After trying a bunch, I gave up and installed very large filters on the output.

    If you have a lot of area to light, go for 24V strips as you can get much higher wattage while staying within class II limits.

  3. jadziedzic | | #3

    FWIW, I've found DiodeLED brand's Blaze series to be very good with respect to CRI and light output. Comes in both 12V and 24V versions, field trimmable, and as Akos mentioned, pricey but worth it.

  4. Andrew_C | | #4

    Indirect lighting is an excellent way to get ambient lighting and reduce glare, but you need more than ambient lighting, so I don’t think indirect lighting will solve all your needs.
    Long answer with some excerpts from previous threads:
    Way back in the day (21 Oct 2011), Martin wrote an article, Martin’s 10 Rules for Lighting. It requires a GBA membership to read now, and lighting technology has gotten better, but the lighting concepts remain the same. In that article, he focuses on Ambient and Task lighting, leaving the Accent and Decorative lighting aspects to interior designers.

    When I was looking at the topic a while ago, there were a number of threads on this general topic, including some comments on glare from Dana. You might find them illuminating (sorry 😉.).

    Aside: the contributions of some people to the quality of discussions at GBA is staggering to me. I appreciate it and find it gives some hope in a time when divisiveness and trolls seem to sidetrack so many things.
    !*********!

    "I am open to lighting ideas, any feedback is welcome."

    An all down-light lighting scheme usually ends up with much lower visual efficacy than balancing it with up-lighting, due to the glare-factor. The definition of glare is when there is a large intensity difference between a light source and its surrounding field is high. That causes human pupils to constrict, which then needs higher ambient light levels for achieving the same visual acuity - humans can see more at lower ambient light levels when the glare factor is eliminated. When there is sufficient up-lighting to brighten the ceiling around the down-lights, or setting the ambient light levels entirely with up-lighting, the effectiveness of using downlighting for accent or local task lighting goes up.

    If you haven't found it already, there is a large amount of lighting-design resources available online at the Rensselaer Polytechnic Institute websites, including discussions on how to effectively integrate daylighting etc.
    http://www.lrc.rpi.edu/

    Answered by Dana Dorsett
    Posted Feb 29, 2016 11:34 AM ET

    Read more: https://www.greenbuildingadvisor.com/community/forum/general-questions/57731/new-construction-surface-mount-leds-j-boxes-or-cans-retrofit#ixzz41aOQPykL

    Second thread…regarding the efficacy of fans, but veering into lighting…

    Efficacy of lights gets complicated.
 By Dana Dorsett
    Lumens/watt or even high CRI (color rendering index) on a light bulb doesn't necessarily an improved efficacy. Visual acuity requires some amount of overall luminosity (the lumens you get out of a bulb), but is undercut by "glare", the technical definition of which is the contrast between a bright spot in the visual field relative to its surrounding background.

    In a high glare environment such recessed lights with high-efficiency LED spot light bulbs the total ambient luminosity required for visual acuity can be many times higher than it would be in a zero-glare environment, such as uplighting coves or wall-washes illuminating the ceiling/wall, using the texture of the building surfaces at a diffuse source of light.

    This can be true of task-lighting as well. A common mistake people make with under-cabinet kitchen lighting is to place the fixture near the wall, directed toward the room, which puts the light further away from the front of the counter where the work is being done, and directing it at your eyes, for maximum glare, and introduces shadow artifacts from your hands. Placing the fixture at the front of the cabinet and directing it at the wall puts more light directly at the work, and fills in the shadows with the diffuse light scattering back from the wall, and eliminating the glare factor of a naked bulb/tube within the visual field.

    Read more: https://www.greenbuildingadvisor.com/blogs/dept/building-science/difference-between-efficiency-and-efficacy#ixzz41aPKuckm

  5. jollygreenshortguy | | #6

    I find a lot of "designed" interiors to be very much over-lit. Our living rooms don't need to have the lighting levels of a hospital surgery.
    If you're designing a space from scratch start by optimizing (not necessarily maximizing) natural daylight. It's the healthiest form of light and also the most environmentally beneficial. In a well designed space it should rarely be necessary to turn on a light during the daytime except for the most light intensive tasks.
    Regarding those light intensive tasks, food prep in the kitchen would be one of those. But you don't need to light up the entire kitchen to the level necessary for that task. Focus the strong light where you need it, on the prep surface with no shadows. Then leave the rest of the room in a moderate ambient level. This will reduce eye strain and save energy.
    Lastly, the natural human cycle of wake/sleep gets disturbed when we light our living spaces too brightly late into the evening. So except where you are doing those critical tasks (food prep, reading, shaving...), consider moderate to low lighting levels.

    Table lamps are under-rated. They're flexible, portable and get the light exactly where you want it. In my living room I installed the usual array of recessed LED lights in the ceiling, 2 wall sconces and I have a couple of table lamps. I NEVER use the ceiling lights. The 2 sconces and the table lamps work perfectly.

    1. Expert Member
      BILL WICHERS | | #7

      I find it's beneficial to put lighting for larger spaces on dimmers so that you can adjust the lighting level to your needs. I have two large chandeliers in my dining room, and the dimming feature is great. I did experiment with LED bulbs to find some that dimmed well, and I use a good dimmer from Lutron. The result is that I can dim from candle light levels up to reasonably bright.

      Bill

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