Having received the just released CREE 60w warm white LED bulb, I wanted to get you my impressions ASAP since many of you are already asking about this ground-breaking bulb.
The vital stats:
- Manufacturer: CREE
- Cost: 6-pack, $74.82 at Homedepot.com = $12.47 each.
- Brightness: 60w equivalent – 800 lm
- Consumption: 9.5 Watts
- Efficiency: 84.2 lm/W
- Life: 25,000 hours
- Usage: Indoor/outdoor
- Assembled in the USA
- Lead free / Mercury free
For comparison, an incandescent bulb has:
- Cost: 4-pack, $6.00 on Amazon (Philips name-brand bulb). Sylvania are close to $0.50/bulb.
- Brightness: 860 lm
- Consumption: 60 Watts
- Efficiency: 14.3 lm/W
- Life: rated 1,000 hours
Based on simple lifetime cost, the LED lasts 25x as long as the rated life of the incandescent and is roughly 25x the cost of the inexpensive Sylvania bulbs, so by that measure, these are the “same cost.” However, that doesn’t figure in inconvenience of having to replace the incandescent 25 times, going to the store, or paying for the electricity! It doesn’t take a physicist to see that the CREE LED bulb is the big winner.
For the 25,000 life of the bulb, the CREE saves 1262 kWh or electricity. That’s a LOT of energy savings! How much? That’s about a month of your home’s entire electric usage. Compare that with your electric bill and you’ll immediately estimate your cost savings. For me, this electricity costs about $200.
The bulb feels different from any other bulb. It must have some sort of rubberized coating on the translucent housing. It almost sticks to your hands. In fact, I felt the urge to wash my hands after touching it. Very strange. The positive thing about this is that you’re not going to drop this bulb., unlike normal glass, which is slippery.
I immediately replace the bulb in my desk lamp, which is an old CFL. That works fine once it warms up, but it always seems to be a dim yellow for the first 10 minutes, by which point, I’m about to leave the room. Note however that I strongly recommend that you use this in fixtures with good reflectors on the back surfaces. Otherwise, you’ll waste a lot of light that doesn’t reflect off the back of the fixture. I learned this the hard way in my downlights (recessed light fixtures). Standard incandescent flood lights have internal mirrored surfaces to project the light forward. These LED lights are omni-directional, so you’ll waste a lot of their light output if they’re used in fixtures without good reflectors.
The CREE, being an LED light, is essentially instant-on to full brightness – very nice.
As for the color, it does appear to be a “warm white.” If you don’t tell someone that it’s an LED, they probably wouldn’t know, which is exactly the effect they’re looking for. In fact, combined with the shape of the bulb, I’m guessing that the only way one would know that this isn’t a regular bulb is when you dim it. Incandescent bulbs grow very warm at lower dimmer settings, whereas LEDs maintain their color temperature throughout the range or brightness.
The next replacement was in one of the downlights in my bathroom. These are particularly important because you want to maintain a neutral skin-tone. Nobody wants to look in the mirror and see a strange skin tone! In this case, the yellowish cast is definitely noticeable compared to the incandescent. I’m not sure why this is, but it’s quite obvious.
I then replaced the LED in my closet, which was a bright blue (my wife says it looks like s dentist’s office or something). The change in color was very apparent – definitely yellowy. I’m not sure it I like it or not. It’s definitely “warmer” but perhaps not as natural. I need to try some of the whiter versions of the CREE bulb which is supposed to be off-white. Here’s a comparison photo:
The container is very white while the counter tiles are almond. The photo was taken using the camera with manual white balance that is tuned for incandescent bulbs, so it will make the incandescent image look as white as can be. If you used a spectrophotometer, you’d get a more accurate image. However, it’s not how you’d perceive the colors.
Looking at the color spectrum, I found what would be expected, the light from the LED bulb consists of three distinct peaks – red, green and blue, whereas the incandescent is a smooth spectrum. In theory, you should be able to come up with a close color match using the three primaries, but contrary to popular opinion, you will not be able to perfectly match the color produced by a continuous spectrum source.
Perceptually, these images are a fairly close match to what I was seeing. Pretty good colors but not exactly what I’m used to. Your mileage may vary!
Here’s a striking comparison between the LED and the CFL using my desk lamp. Again, I kept the white balance on the camera set to “incandescent”, meaning a pure white would match an incandescent (which really isn’t white, but it’s what we perceive as white in our ordinary indoor experience).
Keep in mind that perception changes our reality. The CFL doesn’t really look that yellow, because our brain tries to color balance things. However, the camera is good at showing things without this bias. The main take-home message is that the LED bulb is a vastly better match for what we normally think of as household lighting.
As you try out different bulbs, let us know what you think. The CREE, at only around $10 has broken new ground for quality and efficiency. It’s well worth a try.