LED bulbs move in and mix up home lighting
พฤษภาคม 3, 2011 ใส่ความเห็น
In the space of a few years, I’ve gone from one lighting technology to another and now to three lighting types in my home. I suspect others will be in the same shoes as lighting options expand, notably those involving LEDs.
Eager to cut down my electrical load, I essentially converted to compact fluorescent lighting (CFLs) years ago. Recently, though, I’ve replaced CFLs with efficient LED bulbs and even energy-hogging incandescents to address an unfortunate feature of CLFs: turning them on and off frequently degrades their life.
CLFs are still a good deal both financially and environmentally. They use about one quarter of the energy of incandescent bulbs and will last about 10 years, or 10 times as long, according to Consumer Reports tests. But Consumer Reports also found that turning a CFL on and off within less than 15 minutes, something you might do in the bathroom for instance, leads to earlier-than-expected brownouts.
That rapid cycling issue, plus the arrival of good LEDs in the traditional A19 bulb shape, got me rethinking my home lighting and prodded me to use different bulb types for different purposes. I’m still focused on efficiency, so I’m only using incandescent bulbs in places where the light is used in short spurts. I tend to go in and out of the attic quickly, for example, and want full brightness as soon as possible.
I’ve also added a few LEDs, which are certainly more expensive–a 60-watt incandescent replacement costs almost $40–but functionally they have been good CFL replacements and are more efficient per lumen. I have a few Philips LEDs that give off as much light as a 60-watt incandescent or a 14-watt CFL, and they consume 12 watts.
It will take a long time based on energy savings compared with CFLs to recoup the initial cost. On the other hand, LEDs are supposed to last upward of 20 years, and I placed them in fixtures that we flick on and off frequently, which I hope will address the burnouts I’ve experienced with CFLs.
You don’t yet see general-purpose LED bulbs at the supermarket or corner hardware store, but more products in the popular 60-watt-equivalent category are coming, and prices are expected to continue falling. In the space of the last few weeks, a couple of new LED companies have emerged, and one anticipated product (well, anticipated by lighting geeks at least) is expected in stores soon.
Switch Lighting, backed by venture capital firm VantagePoint Capital Partners, plans in the fourth quarter to start selling an LED bulb which has a cooling system that it says will ensure long life–on the order of 20,000 hours, or 18 years, at three hours a day. The company is readying 40-watt, 60-watt, and 75-watt equivalent bulbs, with prices starting at less than $20, according to a representative. To make light dispersal more even, the LED light sources–small coin-size dots–are located near the edge of the bulb glass, a change from the typical “snowcone” shape.
• Lightbulb wars: More than just LED
• Are efficient LED bulbs worth the price?
• To cut LED lighting costs, Bridgelux rides silicon
• GE pitches halogens as incandescent bulb stand-in
Another company is Pixi Lighting, which introduced an A19 LED earlier this month. It has a color rendering index (CRI) of 90, a measure of light quality, and a color temperature of 3,000 Kelvin, or white light. The 40-watt equivalent, which uses 6.5 watts, has been in an overhead fixture in my house for a few weeks and I find the light quality is good.
Lighting Sciences Group will offer two 60-watt equivalent LEDs with some impressive “feeds and speeds” slated to be available online and in Home Depot nationally by the end of the second quarter, according to the company. Rather than the snowcone shape, the bulb has a thick disk on top of a heat sink to disperse light evenly.
There will be both a “cool white” and “warm white” version. The cool white will give off 950 lumens, have a CRI of 88, consume 13 watts, and have a cool color temperature of 4,900 Kelvin. That product is already available at some Home Depot stores and costs $36.97. The warm white will give off 850 lumens, consume 13 watts, have a CRI of 88, a temperature of 3,000 Kelvin, and cost $34.97.
The design of that product reflects how manufacturers are trying to improve LEDs so that they are suitable for many more uses in a typical home. Until now, LEDs have excelled at directional lighting uses, such as spotlights or downlights in recessed cans in a ceiling. But now GE has an “omnidirectional” LED bulb where the heat sink diffuses light. Cree, too, is working on a 60-watt replacement LED bulb that prioritizes even light along with efficiency (less than 10 watts) and life.
The other significant change in buying LEDs, at least for me, is choosing a color temperature, as LED manufacturers typically offer a cool 3,000 Kelvin and a warmer 2,700 Kelvin temperature, which is similar to the yellow of an incandescent bulb or CFL. I’m also going to pay closer attention to CRI, as I’ve been impressed with the 90 CRI of the Pixi bulb (although I’d like it to put out more light). Some bulb manufacturers are already advertising how their bulbs can be recycled or taken back, another desirable feature in my book.
Purchase prices between $30 and $40 for lightbulbs are obviously a barrier to adoption. But there are some state and manufacturer rebates available, and some people, as I have, will be willing to consider the energy savings, environmental benefit, and other attributes, such as long life and the ability to work with dimmer switches. (CLFs can work with dimmers, but not all of them, so you need to check that when shopping.)
Falling prices and improving performance of LEDs puts people in a similar situation to buying a PC or mobile phone, where the technology is always improving and there’s an argument for waiting. In my case, I’ve stepped into LED bulbs in a measured way and we’ve been happy with the results. Rather than ditch CFLs en masse, I’ll let these different lights coexist while keeping my electricity bills low.