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The replacement bulb calculation from incandescent bulb to CFL was quite easy. The chart was clear:
25W = 4W
40W = 9W
60 W = 13W
75W = 17W
100W = 23/27W
but I have a real problem with the calculation of LED
1 LED bulb is 1.2 or 1.5 watt or depends?
How to calculate a e.g. 21 LED bulbs lamp as an equivalent to incandescent or CFL bulb ?
How would I know how bright is such lamp? E.g. E26 LED bulb could be 68 to 520 lumen. There are A#, R#, BR#, PAR# and E#. ( and probably more )
There is an angle to calculate, lumen to know, clusters, high power and grow light, and who knows what else. LED Light Bulbs - C. Crane Company (800) 522-8863 LED Light Bulbs
Pretty confusing that stuff.
Is there any easy way to understand at least the basics?
It is possible to make an easy to read chart?
I tried some LED lights in various light fixtures, not impressed. They are amazing for "task" lighting like a flashlight where you need very concentrated light but to light up a room, they are horrible. I just put some halogen bulbs in my kitchen in the fixture over our table (on a dimmer so no CFL's) and I really like them. The fixture is rated for 4 100 watt bulbs but I put in 4 60 watt bulbs and they give off as much light and don't get hot like the incandescent lights do. We will see how long they last. I've had them for a couple months now is all.
LEDs are RAPIDLY changing / evolving. The major plants that were making other kinds of lighting devices are shifting over to LEDs.
The best LEDs give more "lumens per watt" than any other lighting technology AND have a color rendering index higher than any other kind of common home lighting source.
There are still some older generation LEDs being sold and some do have poor dispersion patterns, so I would recommend either seeing the bulb "lit up" in the store or making sure you can bring it back it look terrible in your fixture(s), but in time I suspect most folks will demand "the good stuff"...
I tried some LED lights in various light fixtures, not impressed. They are amazing for "task" lighting like a flashlight where you need very concentrated light but to light up a room, they are horrible. I just put some halogen bulbs in my kitchen in the fixture over our table (on a dimmer so no CFL's) and I really like them. The fixture is rated for 4 100 watt bulbs but I put in 4 60 watt bulbs and they give off as much light and don't get hot like the incandescent lights do. We will see how long they last. I've had them for a couple months now is all.
LED lights are steadily improving, though they still have a ways to go....
Capital cost is still an issue. Ultimately, I think they will dominate. Since TV's are now going LED, the demand for large quantities of LED's will soar, so the manufacturing costs should plummet. The best LED bulb I have looked at is shaped and sized just like an incandescent bulb. Inside the bulb the LED's are arranged in a spherical pattern, and the bulb is slightly frosted. It is hard to tell they are not incandescent (other than they don't get warm).
For dimmable CFL's, they have been available for over 15 years. I put 54 of them in recessed ceiling cans in the house, with R40 reflectors behind them. They work great and have a decent color temperature.
Most electric companies will give good rebates/discounts on them... I think I ended up payng about $3 each (and this was 12 years ago, when CFL's were expensive). So it was $162 for the bulbs, but the electric bill went down by $50/month, so the decision was a no-brainer.
I did look at few LED bulbs in the stores and I noticed that some packages list just new wattage ( I don't really care for) and lumens ( yes! its important), but not indicate what they replace ( 15W?, 25W?, 40W?).
Like this:
http://thelightingguyontario.com/images/led453.png (broken link)
or no lumen output in this:
Few facts I learned that day:
- look for # of lumens ( usually 450+ to replace typical 40W bulb, and 900+ for 60W bulb)
- check the color temperature ( if there is a scale - good, if not then just remember the two opposite : soft light 2700k, cool blue - 6500k, and everything else in between.
- color rendering ( CRI ) - color accuracy in reproducing colors of objects: 100 is perfect, 80 is most common.
However color temperature and color rendering info is not required by law.
They are required to include lumens and wattage, only.
But, wouldn't you also want to know what the color temperature is? Instead, you get terms like, "soft white", "cool white", "day light" or other variations.
As a consumer, I think light bulb manufacturers are underestimating their audience. As consumers, we should demand to know what the CRI and the color temperature of a bulb is.
Why not? And then they can rid themselves of the "dumbing down" on their packages that say, "25w=75w".
Please, just tell me the lumens, CRI and wattage and I'll be good to go. Although in all fairness, some manufacturers do indeed include more information such as the label on this package:
No color rendering numbers but typical is 80 anyway.
What the consumer report says about:
Light-emitting diode bulbs (LEDs) Pros:They use slightly less energy than CFLs and manufacturers claim LEDs last 20,000 to 50,000 hours. That's about 18 to 46 years when used three hours a day. LEDs instantly brighten, even in frigid temperatures, and performance is not affected by frequently turning them on and off. Some LEDs we tested dim as low as incandescent bulbs. Cons:Among A-type bulbs, the type used for lamps and other applications, not all are good at emitting light in all directions. And LEDs are expensive, $20 to $60, and can take four to 10 years to pay for themselves, based on our tests.
Also keep in mind that the majority of CFLs are made in China and most incandescents are no longer made in the U.S. Only the top-rated EcoSmart and Go Green were still made in America.
The above pictured "Lights of America" LED light bulb is Made in China. Lights of America has overstated the light output and life expectancy of its LED bulbs and misled consumers about how the brightness of its LED bulbs compares to traditional incandescent lights.
Lights of America LED bulbs 2025LEDE12-65k claim 40 watt bulb equivalent and 30,000 hr life. Real world says 25 watts equivalent and maybe 1,000 hrs. Do not buy this junk. ( Walmart ) http://www.ftc.gov/opa/2011/02/lightsamerica.shtm
I tried some LED lights in various light fixtures, not impressed. They are amazing for "task" lighting like a flashlight where you need very concentrated light but to light up a room, they are horrible.
if you buy the cheap home depot or lowe's LED's, then yes, you won't be impressed.
we've been retrofitting buildings for a large client with all LED's, and they are fantastic.
for the interior lighting we use CREE trim that are similar to what you see in home depot, but roughly 4x the price. And we've been using LED strips running the length of the buildings to illuminate the exterior walls; they're not very big, maybe 2" in width but they put off an incredible amount of light. But very pricey.
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... but still the calculation is very confusing.
