LEDs for general home lighting
LEDs for general home lighting
(OP)
Whats the light quality,energy efficiency and cost effectiveness of LEDs for general home lighting in 2004.
Lots of hype starting - see - http://www.luxeonstar.com/
One watt this year,ten watts next year, 100W after ? ?
Streetlights in five years ? ?
Lots of hype starting - see - http://www.luxeonstar.com/
One watt this year,ten watts next year, 100W after ? ?
Streetlights in five years ? ?





RE: LEDs for general home lighting
RE: LEDs for general home lighting
While LED's provide the directional lighting required for traffic signals and possibly street lights and other directional lighting like spotlights and tensor lights, it's not clear if general purpose. omni-directional lighting is an efficient usage of LED's.
The reason is that anything that you use to alter the directionality of the LED lighting will reduce the overall efficiency of the system, which means that only in the case where you don't want to be bothered to replace lights would you use LED's for that purpose.
As for reliability, LED's are not quite there yet. Southern California started converting to LED traffic signals last year and one particular signal on the way to work is now completely dark. It started with a small cluster that grew larger and now the entire array is dark; possibly due to poor design.
TTFN
RE: LEDs for general home lighting
TTFN
RE: LEDs for general home lighting
RE: LEDs for general home lighting
Traffic signals have (?) <45° cone angle AND you are trying to look directly into the light stream, while in most home lighting, it's desireable to have >45° cone angles and you're looking at reflected lighting.
One personal comment about the brightness of LED traffic lights is that they are so much better during the daytime, but tend to be overly bright at night, particularly after being dark-adapted. The first couple of months after the changeout, I would look directly at the LED lights at night and my eyes would actually hurt, but since then, I've adapted by not centrating on the lights at night.
I could see(!!) using LED's to replace tensor/reading lamps, since those applications demand cone angles substantially smaller than 45°.
TTFN
RE: LEDs for general home lighting
http://www.colorkinetics.com/
RE: LEDs for general home lighting
My understanding is that LED's biggest hurdles to entering the general purpose white-light illumnation markets are:
1. Lousy color rendition
2. Low power densities (which means big sources & poor light control/focus & large fixtures)
3. High cost
All three of these are slowly being improved.
There are actually two manufacturers out there (that I'm aware of) making LED fixtures for the architectural lighting market -- ColorKinetics is one. . . And the name of the other slips my mind right now. . . .
Anyway, they both offer big flat LED array panels. Interestingly, you can control the color output from these things to any color of the rainbow. On some models, you can even drive them somewhat like a very low resolution TV (200x200 array or something like that).
But those things are very high priced.
And the white light that they generate doesn't come close to traditional white light sources -- if you want real white, or color rendition, stick to incandescent or fluorescent or metal halide.