Hold the phone! A valid LED product?! Finally.

Okay, so the title is a bit brutal, there are LED products that are valid, and by "valid" I do mean "for real lighting jobs under normal circumstances", por ejemplo:
- If your relamping plans involve the word "scaffolding", maybe LED is a good choice.
- If your project goals involve the words "LEED" (is that a word or a phrase or ...) and/or the name of a metal like silver, gold, or platinum, maybe LED is for you.
- Cove lighting
- anything where color is involved ... and I'm not talking about cool white as a color

What I keep hoping for (think back to recent posting on the promise of LED) is a real, normal, generic luminaire with LED as the source. Well, I think we finally have one that meets my uber-nerdy criteria for a proper LED luminaire. Gotham has 4" solid state downlights that absolutely kick the snot out of anything you can do with CFL (let's assume incandescent is dead since the DOE is on a mission to rid us of this useful plague).

For years there seems to be an objection to a 6" hole in a 8-9ft ceiling. Who knows why. Who knows why once The Decider finds out they are looking at 35-40% efficiency. You'd think logic would trump "gaping holes". So what I have seen a lot of is people using CFL because it is better than incandescent for the ol' power budget, but yet it doesn't output hardly any usable light. Good gravy.

With LED, we can have a 4" hole and calm the aesthetic nerves of that chunk of the industry while not creating ulcers on the ASHRAE 90.1 committee.

(Grant me some liberty with specific Watts please; none of know what gets shipped day-to-day.)

4" 26TRT = 590 lumens and 28W = 21 lpW with a 1.0 S/MH
4" 18TRT = 530 lumens and 19W = 28 lpW with a 1.0 S/MH (notice how aperture governs output?)
Can't get any more lamp into that due to heat ... onward and upward to the 5"-ers ...

5" 32TRT = 1050 lumens and 36W = 29 lpW with a 1.2 S/MH
Well, so much for that idea ... 32W is the cap there ... of we go to the 6"-ers

6" 42TRT = 1300 lumens and 48W = 27 lpW with a 1.0 S/MH
Again, can't cram a bigger lamp into that one. Why do I keep trying ot get more light out it you ask? Hold that thought.

8" 42TRT = 1800 lumens and 48W = 38 lpW with a 1.0 S/MH (still only 57% efficient)

:: drum roll :: (and why I stopped there)

Gotham ALED 35/18 4AR LS = 1600 lumens and 38W = 42 lpW with a 1.25 S/MH

Moral of the story? You can have a 4" hole that puts out the same light as a 8" hole (and BTW that is not 2X the hole, holes are seen by apparent area and that would be related to area; it is pi*16 versus pi*64, and that is then a factor of 4!) but it is 20% less power.

I'll ignore the fact that we have 4X the luminance out of our 4" wonder. Count your blessings, I just wrote something positive about LEDs.