LED Light Fixtures for the Home?

HBergeron writes "Despite some exhautive searching I have able to find very little about LED based light fixtures for the home. There are some in marine use, and a spare handful of others come up on a Google search but from all I have read on Slashdot I have to believe there are more out there. I am in the final stages of a home remodel and would very much like to use 'the lighting source of the future' (tm) in a number of places. For one, the bedroom, LEDs could make a nice bedside sconce/reading light, and a red/white option could be just the like for those late night stumbling across the room expeditions. A vanity light seems like another good place. Not to mention energy and bulb replacement savings." While these may not be economical for most people, I'm sure there are a few folks out there who have put these new lights to the test. How well did they stack up to the use of traditional filament lights?

Comments

LED are as effcient as Incandesent

[master_xemu]

White LED lights actually are only as effcient as regular incandecset bulbs. If you are looking to save money you are better off going with CF, if you want effciency go with metal halide.

Re:LED are as effcient as Incandesent

[eXtro]

That's not true. The heat in an incadescent light bulb is a sign of it's inefficiency. You want energy emitted in the visible light portion of the electromagnetic spectrum, not the infrared.

Re:LED are as effcient as Incandesent

[Meowing]

Yep, it is true that white LEDs aren't yet any more effiecient than incandescents if you want general room lighting.

They do currently have some advantages if you want controlled directional lighting, but that does limit the applications quite a bit. A comparative chart of energy vs. light output can be found here.

At present, fluorescents are much more energy efficient than other practical alternatives for home use. There is still the issue that they contain mercury, though.

A couple of places to check out...

[Anonymous Coward]

LED light bulbs

LED brass desk lamp

Several models to choose from

DC Voltage

[Syris]

LEDs require a DC voltage and current to run(typically ~3V and 20mA) as opposed to the 120V AC voltage wired to throughout your house.

You would need some converters as well as LED driver chips to run the 'bulbs' optimally.

This is all doable; it's just a lot easier to use one of the many, many, many types of incandescent bulbs.

dansdata letters

[FrenZon]

Dan covers this in one of his more recent letters sections. He states that compared to Halogen bulbs, LEDs aren't as efficient, and are best suited to accent lights.

But he says it better than I could.

Not as efficient as some claim

[photon317]

I did some research on this a while back, with the intent to purchase or build some LED lighting systems. As it turns out, for practical, normal household use, LEDs aren't as efficient as some would have you think. You're better off with some form of flourescent lighting. Where LEDs shine is in spot-lighting situations - such as desk lamps, or small spotlights that go under the bottoms of cabinets to light up counters, and that sort of thing.

They provide more light per watt of energy consumed to a small focused area than other technologies, which spread their light in all directions and are masked/reflected to give light to only one direction. But for a main light source illuminating a room in all directions, they're somewhere in the same neighboorhood as incandescents in efficiency, and soundly beaten by flourescents.

LED only good for low power apps

[linuxwrangler]

As other posters have mentioned, the lumens/watt for LED is about the same as for standard incandescent. There are a couple of places where LEDs shine (so to speak).

One is in very low power systems where the LED's output/watt remains fairly constant but the lumens/watt for incandescent is extremely poor. The PALlight flashlight can run in "off" which is actually "very dim" mode for over a year with no problem.

Another is where you want long life and/or color such as in signal lamps. To explain: the lumens/watt for incandescent goes up dramatically with higher voltage but the lamp life decreases in a similarly dramatic fashion. That's why the bulbs on small flashlights where available power is a limiting factor often last only 4-6 hours compared to a standard bulb at nearly a thousand. Signal lamps are at the other end of the spectrum - they need to last a very long time but do so at the expense of efficiency. In addition, much of the light they produce is filtered out to get the necessary green, yellow or red. LEDs produce just the color you want so there are no filtering losses and they don't need to run at reduced efficiency to give long life.

LEDs beat flourescent where you need point-sources of light for focused applications like headlights. Some LEDs are now starting to get somewhat above the efficiency of incandescent and you may see them soon in auto headlights (I've seen a couple of prototypes - tiny led and big-a** copper heatsink).

Finally, LEDs are good in rough-service and high-vibration applications.

For general use around the house flourescent is far, far more efficient and currently far less expensive (last home LED light I saw was well over $100) and the new flourescents put out a very nice light - far nicer than any LED lamp I've seen. With the exception of a reading lamp my wife owned before we got married, every light in our house is flourescent and it really does make a difference on the power bill.

another place...

[Dancing Tree]

www.ledtronics.com

They have lots of light bulbs, strips of leds, etc. as well as a bunch of other neat items (solar lantern, flashlights, flashing safety vests). Some of the household items simply screw into a light socket, others would require some sort of transformer.

not really what you want, but..

[austad]

This isn't really what you want, but it's cool enough to mention here. Target sells an Eddie Bauer branded flashlight that is roughly the same size as the AA Maglite. Except, it has 3 ultra bright LED's on it, which nearly blind you (brighter than the Maglite). They look like Xenon HID's on newer cars. And the best part of all, *200* hours on one set of batteries. $25, so it's a bit more expensive, but the coolness factor makes up for it.

A couple years ago, flashlights like that cost a couple hundred bucks.

Re:not really what you want, but..

[Klaruz]

I found a neat website on this thing:

http://www.ebtx.com/mech/optolite.html

They sound like the real deal. I'm going to stop by target and grab one. :)

Laws of physics

[master_xemu]

The laws of physics show that semiconducter LED technology can't achieve a better than 25% electrcity to light conversion, which would be under flourecent and about half metal halide. Currently white LED's are about 12% efficient.

Re:Laws of physics

[rcw-home]

But do they convert the other 88% to heat the way that incandescent bulbs convert 90% of the electricity they use into heat with the 10% converted to light as almost a byproduct?

Like anything else they follow the law of conservation of energy, so yes. BTW, incandescents are more like 3% light, 97% heat. Either way the light portion turns into heat when something absorbs it. Heat is an amazingly dense form of energy storage, so one tends not to notice it so much, but all other energies are slowly turning into it (entropy).

small applications

[este]

I've got an old '67 volvo, and I was sick of the old-looking green backlighting in my dash. I replaced all the bulbs with blue LED's, and they look great. Kind of expensive, but they'll last forever. Smaller applications like this seem to be the most useful. though here in Eugene, OR, we've replaced the red and green traffic light bulbs with LED bulbs. Still waiting on yellow, a cost issue mostly.........

Re:small applications

[pyite]

Yea, yellow is usually the last to be replaced (I know this because I do work at police departments and one of the departments' computer guy is a traffic detective). The reason is that it's not on very often and isn't as "important." LEDs offer excellent benefits for red and green though. They have faster response time, translating into more stopping distance at speed. Plus, they are brighter, and you can see it. And they save money in the long run because they don't need to be replaced as often.

LEDs are cool, fiber-optic is cooler

[maggard]

LED's aren't necessarily the "lighting-of-the-future", actually fiber looks more likely:

1. Fiber is cheap these days, especially the 2nd rate stuff left over from telecomms and reused for this
2. One or two centralized light sources can provide all of the lumens needed for a home or office
3. Those one or two light sources can be optimized for output, their heat vented directly outside or recovered for use in the building, built to be super-efficient, etc.
4. Maintanence becomes trivial and cheap with the sources placed conveniently, not scattered all over in ceilings, up walls, etc.
5. The fixtures themselves are very versatile, basically a diffuser of your choice. Want a spot snap on the head for that, want a bulb-look pop on a frosted plastic bulb, same for strips and coils or flat panels
6. Dimmers on individual feeds are possible with LCD adapters, the same is true for color filtering
7. No RF noise, no flicker, durable, cool, efficient, fixtures never need replacing, what's not to love?

Frankly I look forward to having one or two "light boxes" in my attic keeping much of the heat out of my living space (or in the winter pulling it into the HVAC system), only having to replace a few well engineered super-efficient bulbs in a handy box every few years, plugging in a fiber cord instead of a an electrical one for a lamp. LEDs might become a good retrofit for older wired-not-fibered places but for new construction I'm looking to plastic.

Color Kinetics

[Das Kamikaze]

Color Kinetics have a number of LED light product lines, both professional and consumer. Their consumer branch, Sauce makes an assortment of wands, flashlights and nightlights, while their professional arm has done a number of Huge installations.

As for prices, I'm sure if you have to ask, you can't afford it...their 4 color intelligent nightlight looks relatively cool for $8.

Compact Fluorescent

[Yonder Way]

I can't believe I haven't seen it mentioned here yet (maybe I am browsing at too high a threshhold), but compact fluorescent lights are the current way to get the best bang for your buck in home lighting.

You get roughly a 4:1 amount of light per watt in a compact fluorescent as compared to a conventional incandescent bulb.

I recently went through my parents house replacing bulbs. I used mostly ~15 watt bulbs (60 watt equivilant) and in a couple of areas where really bright light was needed I used 27 watt bulbs (~100W equiv.)

There were two fixtures in the hall that used a total of 600W of light originally and now use a total of 60W using compact fluorescent bulbs. The hall is still quite bright, but now use four 15 watt bulbs as opposed to eight 75 watt bulbs.

It doesn't take a math genius to see that these bulbs pay for themselves relatively quickly via savings in the electric bill. Not only that, but they last a long time. I've been using them for about six years and I've had only *one* bulb die in that timespan (that was a Philips if anyone wants to know).

Home Depot is selling them pretty cheaply right now. There is no excuse to not buy a pack and try them out. You are totally justified in spending the money for the bulbs up front and put them in now, knowing that if you annualize your costs you are actually saving money.

These bulbs cannot be used in dimmer type sockets, and other than the really small 9 watt models some of them have a hard time in very small enclosed fixtures.

You will realize the most immediate savings if you replace bulbs that are in use for extended periods, like driveway lights or hallway lights.

I built them myself and they are great.

[jakedata]

I have an off-grid camp and desired safe and efficient lighting. I loathe fluorescent light.

So I have a small (300 ma) solar panel charging a 12 Volt gel cell that I salvaged from a UPS.

Rather than use resistors or a dc-dc converter, I wired the LEDs in series. I made strings of 5 LEDs and wired the strings in parallel. (think christmas lights) Peak voltage on my circuit can be > 14.8v

Hints:
The light was extremely white/blue so I made some yellow strings and mixed them in. Cheaper that way too.

I used a cheap wirewound potentiometer as a dimmer because it was too bright for night reading.

I made the electrical connections into a self-supporting frame for the LEDs rather than using a backing material. That means the clear LEDs and fine wires disappear into the background. When it is off it is nearly invisible.

The LEDs I used (Hewlett packard, purchased from Newark Electronics) are extremely focused and directional. It took some careful aiming of the individual elements to get a good spread. You might consider a diffusor.

Good luck, and I will be happy to answer questions if you have any.

Next time I make some, I am going to make seperate red, green and blue circuits so I can tune the color balance.

-j

Paint those walls with light

[rich_r]

Using these!

Using them in the venue I work in and they really do look great!

YMMV on whether they're appropriate for your home application though! I would suggest, however, if you are going down the hardcore-lots-of-new-fixtures-everywhere route that you consider using fixtures that talk DMX, which'll make life a darn sight easier when you want your rooms to slowly change colour over the day!

Not LED's, but we like our Microsuns

[dpbsmith]

Not LEDs, but I thought I'd mention that we currently have three Microsun HID metal-halide lamps in our house and are very happy with them.

Microsun makes table and floor lamps that are nice-looking pieces of furniture, mostly of wood. Not cheap but not out of line for "nice furniture." They incorporate a "gearpack'" which holds a 68-watt E17N metal-halide HID bulb and two conventional 25-watt incandescent bulbs.

The company claims "more than 300 watts [sic] [sigh...] of crisp white light, yet uses less than half the energy to do so." I think the claim is reasonable. The bulb package, annoyingly, does not state the light output in lumens, but such bulbs typically seem to have an output of about 5000 lumens. (The 25-watt bulbs, of course, don't add very much light but are just there to warm up and smooth out the spectrum).

That is, of course, not nearly as energy-efficient as fluorescent. However, most of the compact fluorescents we've tried really have fairly unpleasant color balance AND just don't put out much light.

These lamps put out a LOT of light and the color balance is quite pleasant. And they just look "normal," small bright sources of light inside a lampshade that light up the room just the way traditional lamps do.

Nothing revolutionary here, just nice, bright, ready-made, energy-efficient lighting with no "geekiness."

Physics of LEDs

[Spamalamadingdong]

The way LEDs work is by allowing electrons and holes to combine under conditions favorable for the production of photons. If a photon is produced, great! If not (say, an impurity traps the energy of recombination), the energy instead goes to vibration of the crystal lattice: heat. The same is true of semiconductor lasers.

It's pretty hard for a crystal of gallium indium phosphide to generate mechanical vibration (no piezoelectric effects that I know of, and no variation in the applied voltage to drive it) or EM at other wavelengths other than thermal IR at the temperature of the device (what quantum processes exist to produce photons at near-IR wavelengths?). So the answer is "You can bet on the remaining energy going to make the device warm."

Re:Physics of LEDs

[unitron]

Thank you, that was interesting, informative, and well-written.

No doubt someone will be along to mod you down any moment.

They do

[Andy Dodd]

http://www.luxeon.com/

Currently the largest LED is Luxeon's 5 watt emitter, which gives off around 100-120 lumens. No one has been able to manufacture anything larger easily yet. There's a rumored 10W LED coming from another company, although its light output is specced as LESS than Lumileds' Luxeons (i.e. it's less than half as efficient.)

5W units are $40/each in small quantities, dropping to $24 or so each in larger quantities (100+) They are VERY hard to obtain.

More on Luxeons

[Andy Dodd]

Go to http://www.candlepowerforums.com/ - It's the closest thing you can get to a "Luxeon Star User Group" :) - There are a lot of flashlight modders there that use LOTS of Luxeons in their projects. People have started using Luxeons elsewhere, too. (One guy on the forums builds Luxeon-based replacement dome light modules using 1W white LS units + a DC/DC converter circuit he designed himself.)

Very little in the terms of line-powered lights, but people are starting to experiment (very carefully...) in that area.