LED house lights
Is it time for you to switch over?
You have probably seen LEDs before: camping headlamps, LED Christmas lights. How about LED house lights? If LEDs are so efficient, why aren't manufacturers lining up to produce LED lights for homes, and why isn't the public lining up to buy them?
In this article I'll try to answer some basic questions about LED lights for homes, to help you understand where we are in the evolution of LED house lights, and how soon you might expect every house on your street to be lit up by energy saving LEDs.
Will CFLs and LEDs save the planet? Find out what others think, and post your own ideas.
Since there seem to be more questions than answers on LEDs, I've organized the article as a series of question headings and answers below each heading. Here are the main questions I address:
- Are LED lights really more efficient than CFLs or Halogen?
- Are LED lights reliable?
- Are LED lights bright enough for general purpose lighting?
- Can I just replace existing light bulbs with LEDs?
- What LED house light options are there other than bulb replacement?
- Will LEDs provide an attractively colored light to my home?
- How much will I save by installing LEDs?
I'm not going to try to sell you on LED house lights as the way out of high electricity bills or as the most environmentally friendly lighting solution around. Frankly, I think LED lights for homes have a ways to go yet, in terms of performance, reliability, and cost, before it will make sense for most owners to switch their home lighting over to LED lights. There are some LED applications you should consider right away, such as LED Christmas lights. And it's fun to experiment with one or two LED house lights right away. But I wouldn't urge a wholesale adoption of LED house lights just yet. Instead, try buying a few, and see if you like the quality and intensity of their light. They will save you energy, for sure, but you might want to do a small investment and see if they suit you.
In October 2008, when I first wrote this page, I said LED lighting would probably make a lot more sense in a year or two. As of May 2009 I am seeing some improvement in the reliability and light quality of LED offerings. The LED products I feature on this page get high customer reviews and are said to have excellent light quality, and of course they offer very long life and very low energy use.
Don't forget to see my LED savings calculator if you want to figure out how much you might save by upgrading regular lights to LED house lights, and whether the payback period is short enough to make it worthwhile!
Are LED house lights really more efficient than CFLs or Halogen?
LEDs are much more efficient at converting electricity to visible-spectrum light than traditional incandescent light bulbs. Just compare my incandescent Christmas lights from 2005 with those I put up in 2007: in each case there were 35 bulbs per chain. The incandescent chain used 3 watts per bulb, for a total of 105 watts of electricity. The LED Christmas lights used a total of under 2 watts for the entire chain. That means the LEDs were over 50 times more energy efficient than the incandescent bulbs.
There is, of course, a catch. LEDs have very highly directed light. Unlike an incandescent light, which typically casts its light over a wide area more or less equally, LED house lights are very focused, so that the area they shine on directly is quite bright, while the further you go from the direct beam of light, the fainter the light provided by the LED house light. In the case of LED Christmas lights, that doesn't matter so much. The point there is to have some nice bright points of light, which LEDs do much more efficiently than incandescent lights. But if you're trying to light the dining room with a single light fixture, an incandescent light bulb is going to send light all over the room (including on the ceiling, for some fixtures). Not so the LED house light. It will point straight down (or in a variety of directions, for household LED light bulb with several diodes) and chances are, it will illuminate a much smaller area.
When you see LED manufacturer or merchant claims of LED light capacity, you need to be wary. A rating in Lumens, the typical measurement of the brightness of a light, can be misleading when applied to LED lights for homes, because of their very focused beam. Lumens is typically measured using a photo sensor placed directly underneath the light, to measure the amount of light received in a given area (for a more technical, and amusing discussion of light measurements, see Lumens, Illuminance, Foot-candles and bright shiny beads...). A 2-watt household LED light bulb might have the same lumens rating as a 50 watt incandescent or halogen lamp, or as a 15 watt compact fluorescent, but the LED lamp may only illuminating a narrow beam directly beneath it, whereas the incandescent and compact fluorescent lights in particular will light up a much broader area, and still provide that same lumens rating for the area immediately beneath the bulb. Make sure when you purchase an LED house light that you check its beam width.
As for halogen lights, they aren't any more efficient than incandescent lights, in case someone told you otherwise. So the same efficiency considerations apply when comparing LED house lights to halogen lights, as when you compare LEDs to incandescent lights. But since halogen lights are typically much more focused than incandescent lights, LED houselights that are designed to be swapped in to replace halogen pot lights are both much more efficient than the halogens they replace, as well as providing a light of more or less similar intensity and focus.
LED house light manufacturers are working around the problem of the narrow beam of a single LED, by building household LED light bulbs that are a collection of individual LEDs, with each LED aimed at a different angle, so that a wider area is highly illuminated. This increases the angle of full light provided by an LED bulb. However very few such bulbs provide the breadth of room coverage of traditional incandescent bulbs or compact fluorescents.
I recently lived for a month in a solar-powered cabin, whose lights were complex LED house lights with about 20 LEDs per bulb. When you looked up at the bulbs they were quite impressive - plenty of light coming out, too bright to stare at for more than a second, and only using about 2 watts per bulb. But when you sat down and tried to read a book, it was next to impossible to get enough light to read by, unless you positioned yourself directly underneath where the center of the beam projected, and even then the lighting was less than ideal. I have also heard others complain that a household LED light bulb for which they paid $35 or more, didn't provide nearly the light they had hoped for, or that the manufacturer's claims of brightness claimed.
Where LED lights are an improvement over existing installations is as replacements for lights that are (or should be) highly area specific. For example, if you have a light in a narrow corridor whose main purpose is to help people find their way from one room to another, you really only need directed light. Having an incandescent bulb shine light all over the place is a waste if you only need bright light on the floor, with a small amount of extra light on the lower walls. In such cases an LED house light is a perfect solution: you'll save up to 90% of the energy costs by switching from either an incandescent or a halogen light to an LED house light.
Task lighting is another area where LEDs shine. Why light up your entire work room if all you need to see is what's on the work bench right in front of you? A couple of household LED light bulbs hanging above the work bench will do the trick nicely. LEDs for task lighting make a lot of sense if you spend many hours working in a small space at the same task - for instance if you're a stained glass hobbiest or wood carver.
Then again, if you only spend a couple of hours a week in your work room, and you need a bulb to light the whole room up as well so you can find the right bottle in the wine rack, or locate the garden sprinkler you put in storage last fall, the LEDs won't do the trick, and you'll have spent a lot of money on bulbs that may take generations to pay for themselves in energy savings.
Finally, you may have seen these excellent LED-based flickering candles on someone's mantle or dining room table. They provide a soft, glowing light similar to that of a candle (shining through the wax), the candle itself feels and looks like a real candle, and they do not create any smoke or pose a fire risk. They last for hundreds of hours on their original battery and you can put in a new battery easily. Just flick the switch on the bottom at the start of your evening, and off again when you retire. I have several friends with these bulbs and they provide great dinner lighting (you can turn off the overhead lights for an intimate mood) and a great conversation piece.
My recommendation: before you go replacing all your lights with LEDs, buy just one light, preferably one to replace a halogen light. There are replacements available for GU10 and MR16 halogen lights that use between 1.8 and 5 watts and should provide comparable light to a 35- to 50- watt halogen light. Try buying one - about $35 on the Web - and see how it works for you. Once you're satisfied with that one, buy a few more halogen replacements, and only after several months of use, try an LED house light replacement for an incandescent or compact fluorescent bulb.
Unless you are swimming in money and don't care about payback period (or are willing to pay top price to save a few extra watts), you are better putting your money into CFLs in the short term.
Are LED house lights reliable?
LED house lights are indeed very reliable, at least compared to incandescent and CFL lights. LED lights for homes are rated to last in the 35,000 to 200,000 hour range, depending on the unit. Compare that to 1,000 hours for a typical incandescent (much lower for cheap generic incandescent bulbs) and 8,000 hours for a typical compact fluorescent.
Note that CFL estimated lifespans are often greatly exaggerated, at least in my experience; I've had a large number of CFLs fail within a year of use, and since there are 8,760 hours in a typical year, they clearly didn't last the 8,000 hours advertised. (I don't leave my lights on all night, after all!) But CFLs are known to fail more quickly when installed horizontally, for instance in a three-bulb ceiling fixture, and I have a fair number of those in my house. Mea culpa perhaps. Wouldn't it be nice if lighting fixture manufacturers made fixtures that made good use of CFLs in their proper orientation!
Whether LED lights for homes will really live up to their long hour range billing remains to be seen - even the 35,000 hour ones would need to be on 24x7 for 4 years before they come close to reaching their advertised range. The main concern with LED house lights is heat. Although LEDs produce very little heat (compared to an incandescent light, which turns 90% of the electrical energy going through it into heat, not light), that heat is concentrated close to the diodes, where it can cause the LED to burn out prematurely. Therefore, on LED house lights where a number of diodes are grouped together to increase the light intensity or provide a broader angle of illumination, aluminum fins are often used as heat sinks to draw heat away from the LEDs themselves. These lights need to be placed in such a way that the heat can go somewhere. So enclosing an LED house light in a small fixture or enclosed space such as a pot light fixture may not be the best way to ensure its longevity.
Are LED house lights bright enough for general purpose lighting?
If you have already bought a few strands of white LED Christmas lights, here's an easy test to try: plug all the lights in, at night in a room inside your house, and bunch them together. Turn off the other room lights. How much light does it cast? I tried this with three strings of LED Christmas lights (about six watts of power consumption) and found the light they cast was close to mood lighting, but not enough to be a replacement for incandescent, halogen, or CFL lighting.
The trouble with this experiment is that the LED Christmas lights send their light in every direction - precisely the failing that LED manufacturers claim is the problem with other types of light bulbs. With properly installed LED lights for homes such as those that can replace halogen or incandescent light bulbs, the light is directed where it's needed, and not wasted illuminating corners of the ceiling no one ever looks at.
The bottom line? The lumens ratings for LED light bulbs are, as I mentioned above, somewhat misleading, as the measurement doesn't cover total light output, only output on a given surface area at a given distance from the LED house light. So in areas where you are okay with more focused lighting such as that provided by a halogen light, then go for LED bulbs. Otherwise, dabble a little - try a light here or there, and see how it works. Probably by mid-2009 to early 2010 the selection of LED house lights will be much greater, the prices lower, and the problems with heat dissipation and beam angle largely solved.
Can I just replace existing light bulbs with energy saving LED house lights?
You can, there are replacements for both standard incandescent lights and the more common halogen fixtures such as GU10 and MR16. There are even replacements for fluorescent tube lights. The challenge is to find replacement bulbs that provide both the same overall brightness and a sufficiently diffuse or distributed light pattern for your application. As mentioned above, LED house lights tend to be more focused than incandescent or fluorescent lights, being closer to halogen lights in their directly focused beam. Some LED house lights are now made with a wider beam angle, up to 160 degrees, but even these do not have the full angle required, for example, to replace a bulb placed sideways in a ceiling fixture.
You also need to be careful that the place you are putting your new LED house lights is well enough ventilated that the bulbs do not overheat. LED house lights age much faster than their stated age of 35,000 to 200,000 hours if they overheat, and if they are enclosed, or partly enclosed, they will overheat.
What LED house light options are there other than bulb replacement?
You can currently buy LED rope, which you can install in sconces or above kitchen cupboards, for example, to cast light up to your ceiling, which if painted brightly will then reflect the light down to the entire room. These LED ropes can be cut to size, spliced together, and powered from a wall socket, or by a light switch if you are handy with electrical wiring. You can buy kits or the individual parts for rope light installation and as long as you have a bit of experience doing electrical work (remember, make sure the circuit breaker for the circuit you're working from is turned off!) and are handy with tools, you should be able to do a fair to middling job your first time through.
There are also LED tape products on the market which you just tape to your walls (by removing the plastic backing so that the tape adhesive sticks to your walls).
Will LED house lights provide an attractively colored light to my home?
The "color temperature" of a light bulb determines how we respond to its light. Color temperature is measured in something called "Degrees Kelvin". Most people are used to the yellowish glow of incandescents (and especially if you haven't changed your incandescents in a long time, that glow will get more and more yellow). Incandescents typically have a color temperature of 2800 Kelvin (2800K). The color temperature of natural daylight, by comparison, is about 6000K, and appears bluish by comparison. Any LED house light with a color temperature of 6000K or over will tend to appear bluish, and any LED house light with a color temperature over about 4000K will appear whiter than an incandescent.
While people are often concerned about how fluorescent or LED lights will make their rooms look hospital-white instead of the soft yellow glow provided by incandescent lamps, you should remember that a little sacrifice in color temperature will go a long way towards cutting your energy bills. Be a trend-setter - start converting your lights to true daylight colors, and save with CFL and LED house lights. You will make it easier for your friends and neighbors to make the change, when they see they won't be the only ones with a slightly bluer light tinge in their homes.
How much will I save by installing LED house lights?
This depends on a number of factors: what lights you have installed now, how much you use them, how much you pay for your electricity, and whether replacing your current lights with energy efficient LED house lightswould cause you to become less careful about turning lights off when they are not in use.
I can only give you the example of my own home, where we have 14 halogen pot or spot lights, 16 compact fluorescent bulbs in ceiling or wall fixtures, one 40-watt fluorescent tube light, and a handful of incandescent bulbs where a light is almost never turned on (such as our furnace room) or where the bulb is exposed and we haven't found an attractive CFL or LED alternative yet. All told, our lights would use about 1,100 watts when all of them are turned on. Assuming each light was on for two hours a day, and given that we spend $0.10 per kilowatt hour of electricity, the cost for us to light the home is 2.2 kilowatt hours, or $0.22 per day. Switching all of these lights to LEDs would essentially save us about 80% of the electricity cost, or $0.18 cents per day, which works out to $64 per year.
Obviously, it doesn't make sense to replace all your existing lights with LED house lights. Instead, focus on replacing those lights where you currently have a very inefficient light in a place where the light is used several hours a day. My advice would be to focus on replacing halogen lights first, then incandescent hall lights and task lighting (where the more narrow focus of LED house lights is less of a problem),and finally to tackle ceiling and lamp fixtures where LED house lights with an appropriate beam angle can be found.
Another great area to replace existing fluorescent or other lights is to buy LED growing lights, as you can grow the same amount of your favorite plants with a fraction as much electricity as used by other types of lighting.
Buy LED lights online: You can find an extensive selection of LED light bulbs at www.environmentalled.com. Environmental LED offers the best LED light bulbs, LED flashlights, LED holiday lights, LED wreaths, LED christmas trees, LED christmas lights and LED landscape lighting. They also offer flashlight and Christmas light recycling.
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