Monday, June 29, 2015

More, On Brightness

This post will address luminaire placement density with good LED downlights, inspired by marketing decisions at Nicor Lighting. Nicor has replaced about-800 lumens, 120° beam angle DLS10 lights, with lights that at 3000°K are 671 lumens (DLS4), or 1022 lumens (DLS56). Builders and consumers need better understanding of the density of placement of such lights. I believe less brightness and less spacing between lights, is good design.

Here is one reference in this:  


The range of human vision.

Some examples of typical horizontal light levels are as follows:
  • Cloudless summers day with full sun - as high as 200,000 lux.
  • Clear moonlight night - 2 lux.
  • Typical clerical office -  500 lux.
  • Underground car park - 20 to 50 lux.
  • Floodlit sports stadium (rugby) - 1500 lux.

This resource says:

Positioning of Lights

Where to position the lights in a new home or renovation is often a worry as once the wiring is in pace it is expensive to make changes.
The following guidelines are based on practical rules of thumb and may be helpful in planning how to place your lights.

For general lighting in the home downlights with the equivalent of a 100 Watt incandescent are a good choice.

Delete the rest of this copy from the web, as it displays incorrectly. The links above work, and are useful.

Much more is needed in this post, wanting a rule book on spacing between LED luminaires dependent on brightness and ceiling height.

If you have lots of can lights at spacing good for 100 watt point-source bulbs, a very common need, Nicor now offers no solution.

DLS4 may be bright enough, but is not compatible, I would happily take out the can lights, swapping in 4" junction boxes for the then-modern DLS4 installation. You would be very happy with results. I can do such patch-outs affordably in  a half hour. Does anyone else do this?

DLS56 will be too bright at 100-watt bulb pitch on eight-foot ceilings. DLS10 did the job well, clipping in more-easily in most situations. We still need DLS10, 

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