LED bulbs brightness

We all kind of know by now that LED bulbs last long. In fact that is the one thing manufacturers try to keep to. At the expense of other things like brightness. (And still some bulbs don't last.) So here we go, I investigate this further. All LEDs are very sensitive to even minor fluctuations in current. My thinking is that because bulbs are built from many such LED units (with ever so slightly different qualities) they have to be under-driven to keep them last long. And that what most responsible manufacturers do. Problem is, this will affect brightness. Lifetime is straightforward - you see when your LED dies. Brightness is a little murkier subject. There is candela, lumen etc. Luminous intensity itself is measured in various circles with various depth. Also LEDs are narrow beam "bare lights", so to compare them to compact fluorescent bulbs or to the now trendy long life light bulbs (incandescents) that are housed in a luminaire (or armature) doesn't compare apples with apples. But let's check out others opinions. cons (mostly) Otherpower had a different position. But they recently reviewed it and them seem to be saying that on the whole they are not as bright as claimed. Not surprisingly, Don Klipstein , the undisputed LED guru seems to be saying the same as he has been doing for some time now. He even calls screw in and other LED bulbs for incandescent replacement a "hype" for the most part. Rob 'Linear' Arnold has a very thoughtful points about a catch 22 for household LED bulbs in the US: Underwriter laboratories (UL) doesn't see the need to list them, and surveyors doesn't see the need to approve them with UL listing. So there you go. Pat Mullins is not convinced about the proper heat sinking of screw-in LED replacement bulbs. I tend to share hat opinion, I and haven't change it. pros Pual Matthews has a good point on the single color department. This he says in favor of LED "bulbs" since LEDs don't need filtering to create colors. And filters take a lot from brightness. Point taken. Conclusion? I still think secondary heat sinks (not just the aluminum plate in the junction) is needed for good brightness performance. And since the best of those is still for external flood light, I am going to assume that the rest is very promising, but in development for now.

Ask the EcoGeek: In the Dark on LED Lights

Dear EcoGeek,

I did a survey and I have 33 recessed bulbs in the house (120W)! I've switched all my non-recessed bulbs with CFLs, but I need something for our recessed lighting.

So my question is why aren't these ultra-efficient LED lights being produced in greater quantities (and this bringing the costs down)?

Thanks,

David

David,

Thirty three 120 watt bulbs will keep your house competing with a small star for both power consumption and light intensity, but I'm not here to judge. If you've got the sockets, they should have high-efficiency bulbs in them.

The good news is two-fold. First, you don't have to wait for LED bulbs to show up at Wal-Mart to find a high efficiency alternative because they've started selling excellent recessed CFLs. I've actually got one shooting down on me right now! To match a 120 watt incandescent, you should look for a 23 to 26 watt CFL.

The bad news is that LED bulbs would likely be a better choice for you, but a good one won't be easy to find. LED lighting is facing a few barriers that will take some time to overcome. First, LEDs are currently fairly expensive to manufacture, and while their extreme long life and efficiency will eventually pay for the extra cost, it's hard to get folks to cough up 30 bucks for a bulb when they're so used to paying 30 cents. You might be able to find a good one somewhere like Ace Hardware or specialty stores online, but be ready to cough up some change.

Second, LEDs have a very high theoretical efficiency, but that doesn't mean they're all created equal. While incandescents and fluorescents have had all their kinks worked out, the materials that will go into creating LED bulbs haven't been settled yet. Engineers at GE, Philips and elsewhere are all slaving away trying to get the maximum light out of the least amount of power without sacrificing the quality of the light…all while decreasing costs.

But I guarantee you it'll be worth the wait. LEDs promise huge energy savings, high quality light, instant turn-on, and long-term lifespans while containing absolutely no toxic chemicals. What's my estimate for a $5-$10 120 watt equivalent LED bulb at Wal-Mart? Five years. Which, luckily, is right around when your CFLs will start burning out!

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