Wednesday, March 20, 2013

Surface Mount LED As Bulb

I walk the light bulb and recessed lighting rows at each visit to Home Depot, looking for something new. I don't know where else to see emerging LED technology. Yesterday, I picked out an example of a bulb-form LED that may fully reveal the light. There may be other LEDs for sale with full reveal where mounted in a can, but I don't yet see them. Salespeople don't understand my interest.

Knowing I would only test this light, I bought one that had been cut open. 

Marking resembles that of now-gone T91. Same wrong 75 watt incandescent equivalence. 
This is made in Mexico, for Home Depot, with bar code 74340 00111, and model ID 409 440.

I paid $24.97, relatively cheap. And, it is available now. But, beware loss of light where this fairly short bulb is recessed in a can. A short can might display all light. Much is lost as with all flood bulbs, where the bulb is deeply recessed.

I admit uncertainty what is under the glass dome. Surely it is a flat array of LEDs, that are fully displayed, surface mounted, if the glass projects from the ceiling.

 14 vs 14.5 watts power draw, 800 vs. T91 at 750 tested lumens.

LED bulb on the left, Philips EcoVantage 100-watt equivalent incandescent on the right. I'll give the LED Brightness Number 7. That's from accepting that stated lumens on a package are correct, and a standard of B6.7 for a straight-on 750 lumens 6" Glimpse/ T91. Then 800/750*6.7 = 7.1. 

Start with definition that a 100 watt incandescent with all of its spilled light, is B4. The incandescent is truly a point source, the bygone concept of an electric candle. Then, know that  narrowing a light beam is generally not helpful. Let it fall straight down, or perpendicular to an illuminated surface, without focus. I judge that the LED flood has a flat plate of diodes on the plane backing the frosted lens. All light is revealed.

Here a 600 lumens T47 is at the right, propped-up over the junction box and more-distant from the wall. B7 vs. B5? Same color temperature. I have guessed at 82% light transmission with the recessed diodes of the T47. 

0.82 * 600/750 * B6.7 = B4.4. Not B5? I admit here that this side-by-side comparison does not discriminate against recession of diodes, light at periphery not revealed. Official definition of Brightness Numbers as task illumination, will have complexity. I'm a little glib. Those applying lumens as brightness measure are irresponsible, perhaps willfully placing disadvantage in plate LED packaging. There is irresponsibility too, in not rating a bulb in a needful fixture that blocks revealed light.

All observed lights here are powered through a Cooper D106P dimmer, full-on. Buzzing? Yes. I haven't learned to rate noise, but here is a try. If T47/ T67 is level 10 on a linear scale, the LED bulb is 5. A 6" Glimpse is 3.

At end-October 2013, this post is edited as I update all of my blog posts, to replace phrase "plate LED," with phrase "surface mount LED." Phrase Plate LED is confused with license plate lighting, and is not accepted elsewhere as a brief statement that the luminaire may be wired directly into a junction box. In my definition, a plate LED is surface mounted, not recessed for foolish styling reasons, to look like a can-mount downlight. Can-mount downlights were a consumer adaptation of theater downlighting, where upon a black ceiling, there is nothing bright to divert attention from a stage. In any circumstance other than a stage center, there has never been a bit of virtue in recess setting of a light. It has been quite disastrous in our waste of the Earth's ready fuels, that many have loaded their can lights with bulbs that are simple point sources, with no reflector bouncing to usefulness, the light that otherwise does not beam downward; all such light and heat energy, totally wasted. Look for all content of this paragraph, and more, in a new blog post under construction. While I edit out the phrase LED Plate Light, I retain the label, temporarily. "Labels" are noted at the bottom of all blog posts, for collection of related topics of interest to a reader.

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