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report from PCBC, led lighting

Posted by zinnah (My Page) on
Thu, Jun 7, 07 at 21:46

Last week I went to Pacific Coast Builders Conference at Monscone in SF. Just huge, walked for 3 hours. Green building was everywhere, and I, among other things, was looking for Title 24 lighting that was compliant and funtionally and aesthetically acceptable. Nothing jumped at me except for Progress lighting which had some interesting recessed led lighting. Some were designed to be screwed into an existing fixture and had trim, drivers and lamp in one unit. The rep claimed 500 lumens, 15 watts, and equivalent to 65 watt incandescent. This retrofit unit is now available in a dedicated fixture so it is Title 24 compliant. Since the ambiant light in Moscone was intense, difficult to judge this claim. I asked price and he said $100 per fixture, including trim, driver and led lamp, which sounded quite good. I checked their website and could not confirm any of these details. Progess is working with Permlight on these fixtures and their website had more details, but still not enough to back up rep's claims. My current project is too far along to change, but these fixtures are probably worth watching and possibly trying when distribution catches up with marketing.


Follow-Up Postings:

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RE: report from PCBC, led lighting

The rep claimed 500 lumens, 15 watts, and equivalent to 65 watt incandescent.

Sigh. When are these guys going to quit exaggerating the incandescent eqivalence? A 40 watt incandescent bulb emits 500 lumens.

This unit has an efficacy of 33 lumens per Watt. That's better than a 40 watt incandescent (12.5 l/W), but it's kind of pitiful compared to compact fluorescent at 60 l/W and T8 linear fluorescent at 80-100 l/W.

As I've said here before, trying to light a home with LEDs is like driving coast to coast in an golf cart. You can do it with a herculean effort, but it's the wrong tool for the job. So now you have a golf cart that can go 20 mph instead of 15 mph, but I'm sorry, it's STILL the wrong tool.


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RE: report from PCBC, led lighting

I'm with David on LEDs for general illumination - so far, there's no there there. Still, I appreciate the report.


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RE: report from PCBC, led lighting

I believe the point is that led technology is evolving and may bcome a resonable alternative. That they have, or so they so they say, a Title 24 compliant recesssed fixture is particularly interesting. I am willing to test this fixture , or it's next generation, for $100, if that turns out to be the price. Flourescents unquestionably have a very efficient lumen per watt output, but for many applications the type of light they produce is not satisfactory. These fixtures are dimmable and directional. And, yes, I am skeptical.


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RE: report from PCBC, led lighting

I know I sound like I'm very down on LEDs, and that's not at all true. I see them as ideal for situations where low luminous flux but high brightness is needed (indicators, brake lights, traffic lights, etc.). For a number of reasons, they work great in small flashlights. They are just the thing where you need intense, bright colors (filtering white light is inefficient; it throws away too much of the light). I love 'em as colorful Christmas lights.

However, LEDs are just not yet suitable for general illumination of buildings. I fact, I'm going to go out on a limb and say that I think that's the nature of the beast as it exists now.

By endlessly tweaking LEDs, and using large numbers of them, it may eventually become possible to make them work reasonably well for home or office lighting. There's every indication that the researchers are determined to do this. They probably will, though I think it'll be a good 10 years or more before serious lighting LEDs are selling at a price that normal homeowners will be willing to pay.

It would be interesting if I were proven wrong. If the researchers were able to produce a single LED (not an LED array) that could yield, say, 1000 lumens with a consumption of 10 watts, with a wide range of color temperatures and good color rendition (80 or higher), then I think they'd really have something.

I think the golf cart analogy is a fair one. It's the nature of THAT beast that it's unsuitable for a coast to cost trip, but I'll bet someone's done it (I know that people drove King Midgets across the US 40 years ago, and those were basically glorified golf carts ;-).

If the golf cart had been invented before the automobile, maybe researchers then would have put huge amounts of effort into developing extra high output golf cart motors and cascading 20 or 30 of them to make a golf cart that worked for such a trip. Think how expensive it would have been! But that's analagous to the current LED fixtures.

No doubt LEDs can be made usable for general lighting by main force. Personally, I think the effort would be better spent on improving existing discharge lighting systems and on developing better and more affordable dimming systems for them. However, nobody in those labs in Berkeley, Tokyo, and / or Beijing has asked for my opinion. ;-)


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RE: report from PCBC, led lighting

How about if we change the "golf cart" metaphor to a Canastoga wagon? Then we can look at this problem from a view of "need for product development" angle. Davidr's valuable input establishes the need for these lights to be improved in order to be realistic for today's world. Given that metaphor, we'd put them in our house if they reached the Model-T phase. For now, we are settling for 3 low-voltage pendant halogens and a bunch of CFL cans for our new kitchen.

Keep in mind that it wasn't long ago that people said CFL's weren't feasible for household use.


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