the 100W bulb lives on....

The 4 Watt bulb has been burning for over 100 years.

It has a world record for it. Carbon filament.

What is its luminous efficacy? It's not hard to make a bulb last forever if you run it cold enough. But there's not much point, given that the increased electricity costs to get the same amount of visible light far outweigh the savings on the bulb costs. IIRC, even normal "long life" bulbs are a false economy in that regard (they may, however, be worthwhile for bulbs which are awkward to change).

Is there a failure of comprehension here? The measure, H.R. 2417, Better Use of Light Bulbs Act, which would have repealed those provisions of the Energy Independence and Security Act of 2007 which federally ban the manufacture and sale of certain light bulbs,

*failed* to pass in the house. So the 100W bulb is scheduled for extinction.

Good. It will speed up LED lighting, and probably save a good few power stations from needing to be built

--
Dirk

http://www.neopax.com/technomage/ - My new book - Magick and Technology

I see Home Depot is selling 60 watt LED floodlights that only consume maybe 10 watts. They had one on display next to an incandescent, and it was hard to tell the difference except for the heat. Still pricey though at $47.

-Bill

Bill,

I think that is the point.

How much was the cost of the 60 Watt Flood ?

How many would you have to buy to match the life of the LED flood ?

Plus the cost of 50 Watts for the life time of the LED flood.

Work out those numbers in your area.

hamilton

rote:

Yes, you are right, but I see 1 watt LEDs on ebay for around $1 each, so you could make a 10 watt unit (60 watt equivalent) for maybe $10 plus time to do it.

Figuring 5 hour usage per day, that would be a savings of 0.25KWH at

15 cents per KWH, or about 4 cents per hour. So, a $10 unit would pay for itself in about 250 hours or 250/5 =3D 50 days. That's not too bad, I can wait 2 months to get my money back. But I might not use it 5 hours a night. It might be a fun project, I have little extra cash in my PayPal account, so I might buy a few LEDs and make a floodlight.

-Bill

h

Opps, I think I screwed up the math. If I save 50 watts, the savings are 1/20 of 15 cents, or 0.75 cents per hour (0.0075). So, I need 1333 hours or 266 days to break even. Probably a couple years would do it.

Sorry about that.

-Bill

You have it backwards. It's CFLs that catch on fire, not incandescent.

--
It's easy to think outside the box, when you have a cutting torch.

Wal-Mart & Dollar Tree have a good price on 4-packs.

--
It's easy to think outside the box, when you have a cutting torch.

Then you know something UL doesn't....go ahead and put the incandescent in a cellulose packed ceiling and see what happens- that's one way to test the fire retardence.

" snipped-for-privacy@att.bizzzzzzzzzzzz" wrote in news: snipped-for-privacy@4ax.com:

every "100W equivalent" CFL I've seen consumes around 23W. A "75W equivalent" CFL is around 18W.

BTW,if you buy 130V "contractor" bulbs,they last even longer. Or put them on a dimmer,slightly dimmed,and they last longer.

--
Jim Yanik
jyanik
at
localnet
dot com

With same or better performance in life expectancy?

At least the same efficiency - after the light goes through whatever optics are needed?

Same or better color rendering properties, and same color of emitted light? Warmer color (less than 4100-5000 K) and higher color rendering index detract from lumens/watt of LEDs.

--
 - Don Klipstein (don@donklipstein.com)

My experience is that a decent 25 or 26 watt CFL is equivalent to a "standard" 100W CFL. 15-watters are marketed as replacing 60W incandescents.

--
 - Don Klipstein (don@donklipstein.com)

CFL circuit boards *are* known to burn, no kindling needed.

They already last years. What's a little more?

The comparable incandescents here are PAR, R and BR floods. Note the CFL here is a PAR30 longbeck. I just looked up a 90W PAR incandescent -

1280 lumens, and that's a halogen one.

CFLs do degrade with use, something like 15% at 6,000 hours nowadays.

Except for comparing between an A19 and a flood with much greater optical losses.

My experience is that in lamps with harps, non-reflector lamps are used, and plenty of CFLs rated 1750 lumens or more (26-30 watts) fit.

I use CFLs in my bathroom, and I like them. They are bright enough when they first come on. (Hint: Use bare spirals instead of CFLs with outer bulbs for brighter starts and shorter warmups.)

As for front porch - the way I usually see those used is turned on and off once a day, or operated continuously - what's the issue with warmup? And, I see plenty of outdoor rated ones doing fairly well in cold after taking a few minutes to warm up.

--
 - Don Klipstein (don@donklipstein.com)

What is the design life expectancy of these at 130V?

(A 100W 130V incandescent operated at 120V consumes 88-89 watts)

750 hours? (1670 lumens at 130V, 1275 lumens 1800 hours at 120V) 2500 hours? (1500 lumens at 120V, 1150 lumens 6000 hours at 130V) 3500 hours with vibration-resistant filament? (1200 lumens at 130V, 925 lumens 8000 hours at 120V)

- Don Klipstein ( snipped-for-privacy@donklipstein.com)

The 100W incandescents I see at Dollar Tree only claim to produce

1100 lumens - less than the 1190-1210 lumen light output of "standard" 75W incandescents.

--
 - Don Klipstein (don@donklipstein.com)