Re: Lighting Question


OK, if Rick, Scott and Barbara jumped in with the LED bandwagon, they probably knew I would eventually write! I’m somewhat known as an LED humbug, but without good cause, I’m afraid. I like LED’s in the right situation and as long as we all admit what we are getting into!

* LED technology is extremely efficient and the spectral power distribution ( SPD or color distribution emitted by the lamp and therefore true color rendering of light reflecting off any surface)is getting better and better. So I see them as a good choice for storage where the heat-sink and dissipation fins of the lamps are not enclosed in a enclosure such as a track lighting can or unvented recessed lighting can.

* We really have no idea how long LED’s will last. They CLAIM to last 20 years but NONE of the better phosphor blends and heat sink technologies have even existed for 3 years,at this point! So NOBODY has a twenty year old lamp that has actually stood the test of time.

* Be aware that LED’s are at the “edge of thinking” in commercial lighting and that there are several things that DO go wrong in testing thus far that impact life:

* As with all light sources, output decreases with time. With LED’s we just don’t don’t know how much and how fast. All the “lamp lifetime” data are interpolations of very short test periods.

* Multi-Phosphor LED’s use phosphors – powders that absorb the UV light created by the LED diode and emit visible light (yes-LED’s do create UV; they actually create visible light using invisible UV light. It’s just captured within the collimation lens). Those powders are heat sensitive. That means that nice, balanced white light may quickly change color – become more green, blue or even magenta as the phosphors break down from heat. The light may still “work” for 20 years, but you might not want to use it.

My point here is that if you sell your CFO on LED’s that will last 25 years and they loose their color after 5 years, you may find finance people knocking on your door with an axe. On the other hand, if everybody gets that it is a calculated risk – that the savings might be real but that nobody knows yet how long today’s technologies will last, and that tomorrow’s technology will be even more reliable, then I’d say you are ready to go LED!