One of the goals I had in my recent house renovation was to change every light bulb in the house to LEDs. I was dividing the house into two apartments and had to pull all the halogen spotlights out of the ceiling that was now a fire separation, and was finishing what was the basement, so new lighting was needed throughout. Most of the house was lit with compact fluorescents, and I never liked them very much.
But the main reason I could do this is the fact that in the last year, the cost of changing to LEDs has dropped like a stone. There is a wide range of bulbs now available for under ten bucks, and if you are willing to spend a bit more there are some very exciting things happening in the LED world.
I started the process with a search for real LED-based fixtures, where the bulb is actually part of the fixture. The idea of putting an LED light and its electronics into a 120 year old Edison base, designed for a time when a bulb lasted a couple of hundred hours, seemed crazy. Surely there must be fixtures designed around the LED instead of just adapting the LED to the conventional lighting fixture.
And indeed there are, but they are few and far between, very expensive or very ugly. I went to a giant lighting supplier and found exactly one, at $500. IKEA, which is now almost all LED, had exactly one, the VIKT wall light, and it is strikingly ugly and useless, pointing light just up and down. Home Depot had exactly one, and it was horrible too. The fancy lighting showrooms have more of them, but they were all out of my price range. I needed a lot of lights.
In the end I concluded that we are in a weird, in between time when the designers and manufacturers have not caught up with the technology, and one has far more options mixing the LEDs with the Edison bases with existing fixture designs. We are just not at the real transition point yet, so I have gone for a transitional solution, buying the cheapest fixture in IKEA (and I mean cheap at $4.99). I must have bought two dozen of them. They will do the job for now.
IKEA is doing a lot of LED education to get people to "think Lumens, not Watts" and is not even publishing the watt equivalent in light output on its packaging anymore. It's not intuitive, and I made a few mistakes. I bought a lot of IKEA 400 lumen bulbs and that's really not a lot of light.
I am much happier with the Philips Slimstyle bulbs that pump out 800 lumens, pretty much equivalent to an incandescent 60 watt bulb. (See Mike's coverage of it here) The difference in electrical consumption is trivial; the 400 lumen bulb uses 6.3 watts, the 800 uses 10.5.
Actually, the Philips bulb is an amazing thing. It looks like a cartoon, like someone stepped on a conventional bulb. It's all plastic, looks and feels light and cheap, but just pumps out those lumens and fits in any fixture. It has become the default bulb around the house and will be around for a while; It has an estimated life of 22.8 years with average use.
For the crystal chandelier that my wife recently inherited, I installed 90 lumen bulbs and it was a mistake; the fixture barely glows. (The wood ceiling doesn't help) I thought that six of them would add up to a reasonable amount of light but they will have to be replaced. Lesson: Go bright.
LEDs come in a number of color temperatures, which are based on the color given off by heated metal. Thanks to a century of incandescents and a few millennia of candles, most people seem to prefer what we call warmer light, which is in fact a cooler color temperature. When cooler is warmer it's hard to know what to buy, but look for the 2700K bulbs; my wife made me take out all the cool white 5000K Philips Slimstyles. In an earlier post I quoted a lighting company:
It is important to remember that indoor spaces lit to lower light levels will typically look and feel better under warm lamps, while higher light levels are easier to tolerate using cool lighting. A space which receives an abundance of sunlight may seem more natural when cooler lamps are installed since their light is closer to high colour temperature of natural daylight.
Go High CRI.
The Philips Slimstyle bulb has a Color Rendering Index of 80, which is pretty good but could be better; the light does not have the full-spectrum quality of an incandescent bulb but it is a lot better than the compact fluorescents that often had CRIs of 60. CRI is " the ability of a light source to accurately render all frequencies of its color spectrum when compared to a perfect reference light of a similar type (color temperature). It is rated on a scale from 1-100. The lower the CRI rating, the less accurately colors will be reproduced." The IKEA LEDARE bulbs have a CRI of 87, which is really terrific; that's almost full spectrum. I don't know why they bury this information because it is important. (here is a PDF I found)
It should be noted that there is some dispute about whether CRI actually works with LED bulbs. The US Department of Energy has concluded that " CRI is generally not applicable to predict the color rendering rank order of a set of light sources when white LED light sources are involved in this set." - They are developing a new index to replace CRI, and suggest that you should pick a bulb because you like it; CRI "should not be used to make product selections in the absence of in-person and on-site evaluations."
The real LED lighting revolution will be RGB
All of the cheaper LED bulbs are what is called Phosphor-converted (PC) LEDs, where, much like a fluorescent bulb, the output of the LED causes the whitish coating to fluoresce in a broader spectrum of light. It is in fact working just like a fluorescent bulb, with the solid state LED replacing the ionized mercury vapor. True RGB LEDs mix three colors together. They are a lot more expensive and not really necessary for basic lighting, but I had just purchased a classic bubble lamp, designed by George Nelson in 1950, and I really wanted to try out the Philips Hue bulbs.
The Philips Hue starter kit comes with three bulbs and a "bridge" that connects to your wifi system. You control it with an app on your smart phone.
Setting it up is ridiculously easy; you plug the bridge into the router, download the app, and press the big blue button. It's a zigbee device, part of " a low-cost, low-power, wireless mesh network standard targeted at wide development of long battery life devices in wireless control and monitoring applications." It talks to the bulbs and relays the conversation to your phone through the wifi system. Perhaps some day the bulbs will be actually connected to the internet, but right now they have to cross the bridge.
And what amazing control you have, up to 16 million colors that can be mixed and matched. Preset "scenes" that you can choose or you can make your own. You can set it on timers to change the color throughout the day, just like mother nature does, to reduce fatigue. I thought it would be a bit of a toy, but in fact it is just amazing. I find that I really do change the colors according to mood and the time of day, going more like sunset in the evening. Other developers have developed apps that let you turn it into a psychedelic light show. And if you don't want to use your phone as a controller, they do sell the Hue Tap, a light switch that still gives you a lot of control.
I also never anticipated how great they would look in a 65 year old design, with each bubble taking on a hue of its own. I bet George Nelson would have loved it. Having this kind of control changes the way you think about lighting, it is almost theatrical. I want them everywhere. I suspect that in a few years these will be as common as having lights on dimmer switches.
It's time to go LED
They are cheap, the light quality is excellent, they will probably outlast you, they use a tenth the electricity of an incandescent and did I say they were cheap? There is no reason not to dump the incandescents and the compact fluorescents now.