Replacement LED light bulbs
Don't be surprised if the lights don't live up to their ad copy
I recently stopped in at my friendly neighborhood Home Hardware to buy some replacement LED light bulbs. They had a bulb that was a standard incandescent replacement bulb, for only $12.99, and used only 5 watts of power. The ad copy on the bulb claimed I would save 90% on electrical use compared to an incandescant bulb.
I was skeptical, because as I point out in my main LED house lights page, LED technology still has a way to go before you can get replacement LED bulbs that are both affordable and provide reasonable light quality and distribution. But I figured it was worth a try - especially knowing I could always take the bulb back if it didn't work out.
I tried screwing the replacement LED light bulb into a wall receptacle in my kitchen where there is usually a 50 watt incandescent. The light fixture is open to the top and the light typcally shines downward through the frosted glass, and upward in the open part to the ceiling.
Within seconds of my turning it on, my wife was grumbling about how bad it looked. And she was absolutely right.
There are three things wrong with most LED replacement light bulbs, in my opinion, and this bulb exhibted all three problems. They are:
- Light is much fainter than the advertised rating
- Light does not diffuse evenly as it does with incandescent bulbs
- Light is a ghostly bluish white, not the 'warm' light of incandescent bulbs
Let's look at each of these issues in turn.
Light is much fainter than the advertised rating
The first thing we both noticed about the new light was that, while in theory it was equivalent to a 50 watt incandescent bulb (being a 5 watt LED that was 90% more efficient than its incandescent equivalent), it seemed to produce about the same amount of light as a flashlight running on burnt-out batteries. In other words, it looked like a 5 watt incandescent bulb! I expected it to be dimmer than the 50 watt bulb it replaced, but not that dim.
This problem crops up again and again in consumer reviews of replacement LED light bulbs - they are nowhere near as bright as they claim. Why is this?
The main reason is that there is no accurate way to compare the light output of LED bulbs and incandescent bulbs, because the way they distribute light is fundamentally different. Incandescent bulbs are omnidirectional - they shine their light in every direction where there isn't an obstacle (such as the screw base or the light fixture itself). Replacement LED light bulbs, on the other hand, are very directed, which means they shine almost all their light in a very narrow cone pointing straight out from the light emitting diode. The typical test to determine how bright a light bulb is involves placing a small photo sensor at a given distance from the light source, and measuring how much light reaches the sensor. So you can have an LED light bulb (say, of 3.5 watts) and an incandescent light bulb (say, of 35 watts) that send the same amount of light to the photo sensor, and claim that the LED light bulb uses just one tenth the energy of the incandescent bulb, for the same light output.
But of course if you were to move the light sensor away from the spot directly out of the center of the beam of each bulb, you would notice that the output of the LED bulb drops off much more quickly than that of the incandescent light bulb. That's because replacement LED light bulbs have that very directed beam. Since you presumably want a wall sconce lightbulb to light up a wide area, rather than a one-square inch patch of space four feet from the bulb on the beam's center, you wind up with a nice bright light when using the 50 watt incandescent. But the LED replacement bulb didn't have a well spread out light - in fact, it just didn't have much light at all.
Light does not diffuse evenly as it does with incandescent bulbs
I've already explained why replacement LED light bulbs don't diffuse light evenly. LED bulb manufacturers try to work around this in a number of ways. They create incandescent replacement bulbs that have the LEDs distributed around a domed surface - so that each diode emits light in a slightly different direction. Or they cap a matrix of LEDs with a textured glass surface to diffuse the light, as was the case with the replacement bulb I bought. Once there are replacement LED light bulbs that really have the true light output of the incandescent bulbs they claim to replace, a strategy like this might work - for bulbs that are hidden from view. But the gut reaction of my wife (and kids) to the replacement bulb I stuck in the wall sconce was partly because of the very strange (ugly, to my wife; real cool, to my 7-year-old son) look of the textured glass.
The best way to switch to replacement LED light bulbs is to rethink how we light our homes. Unfortunately this means more than just unscrewing the old incandescent bulb and screwing in an LED replacement. We need to choose lighting fixtures that take advantage of the more directed light of LEDs, instead of trying to use our old fixtures that give a clear advantage to incandescent lights.
How can we do this? Here are a few ideas on ways you can take advantage of LEDs:
Use replacement LED light bulbs in pot lights (for instance, to replace halogen lights). Pot lights are often distributed across the ceiling of a room or hallway. Halogen lights are actually a form of incandescent light, and they are only marginally more efficient than the regular 49 cent bulb you might use in a regular fixture. People favor pot light fixtures with halogen bulbs, because of the strong directional light they provide, the warm color, and the fact that everyone is trying to keep up with the Joneses, who have them in their newly renovated living room. But if you've got nine 50-watt halogen bulbs spread in a 3x3 grid across your living room ceiling, that's 450 watts you're using to light up the room - way more than you really need. By switching to replacement LED light bulbs designed for the halogen fixture in question, you can cut that energy use by 90% and still get adequate light - assuming the replacement LED light bulbs are adequate. I am still looking for halogen replacement LED light bulbs that are adequate; I'll update this page when I find one!
Use LED rope lights. These lights consist of a transparent plastic sheath with led lights spaced every inch or so inside the sheath. You string the rope lights in an area above people's sight line - for instance, along the top of kitchen cabinets or along the picture moulding near the top of a wall. The light projects mainly upwards, diffuses against a brightly painted ceiling, and shines down evenly on the room. LED rope lights use less than a watt per foot of length, so you can light up a 10x12 room with LED rope lights strung along the picture molding, for under 50 watts of electricity.
Use LED tube lights to replace 48" fluorescent tube lights. While there's less of an energy justification here - since fluorescent lights are already about 3 times more efficient than incandescent lights - if you have a fluorescent tube light that you use an awful lot, it may be worth upgrading that to an LED tube light.
Color temperature of replacement LED light bulbs
I've heard many people complain about compact fluorescent bulbs, and how they refuse to use them in living areas of their house, because the light is a ghostly bluish white, not the 'warm' light of incandescent bulbs. Unfortunately this is true of many replacement LED light bulbs as well, including the one I tried out. The color temperature of fluorescent and most LED bulbs is actually quite close to daylight color temperature, and is measured in 'degrees Kelvin'. Daylight is around 5500-6000 degrees Kelvin (6500 degrees K on overcast days), while most incandescent bulbs are around 2700 to 3300 degrees K. This lower range has a lot of yellow in it, while the higher daylight range is much more blue.
You can purchase LED light bulbs that are in the warmer (lower color temperature) range, but few replacement LED light bulbs in this category will actually tell you exactly what color temperature their bulbs have. They'll just say 'warm white' and you may discover that it's still a significantly higher color temperature than an incandescent bulb. I found one 'warm white' bulb advertised that actually had a color temperature of 6000 - the same as the cool white of daylight! The only LED light bulbs I found that actualy had clearly spelled out color temperatures tended to be halogen replacement bulbs; some of them had color temperatures of 3000 to 3500, which is respectable.
One thing to bear in mind with replacement LED light bulbs is that the warmer the color temperature, the less energy efficient they are. So while you might use 10% the energy for an LED light bulb in daylight color temperature, a warm yellow color temperature LED light may use 15% of the energy of an equivalent incandescent light.
Sometimes we need to compromise
My wife and I are planning a major ground floor reno (actually she's planning it and she strong-armed me into agreeing). When we chatted with the designer we've hired about what we want, I mentioned that I'm into energy efficiency and wanted LED lighting. She was quite dismissive of the technology, saying the light color just isn't right for the indoors. Of course my wife, having just lived through the fiasco of the sconce LED light experiment, wholeheartedly agreed. It seems we are terrified of having indoor lighting be the same color temperature as the out of doors. Why do we need our light to resemble the cave fires or candles of our ancestors?
If you are willing to compromise on color temperature, there are quite a few decent quality LED lights out there, but you do have to shop around for them. And you'll need to pay well over $12.99, at least at this point in the game. You can get fairly bright ones, high quality, with good light distribution - as well as halogen replacement LED light bulbs that provide good directed light. But if you're looking for the perfect replacement for an incandescent bulb - good light distribution, high efficiency, good warm color temperature - you may have to wait a while longer. As one reviewer said who was complaining about the light quality of one of these replacement LED light bulbs, we can put a man on the moon, but we still can't make a decent LED!
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