Mythbusters Light Bulb shootout

MacTech

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They're testing the myth whether it's more efficient to leave a light running 24/7 or turn it off when you're not using it....

one of the things they measured was steady-state power consumption in watts/hour

they had metal halides, flourescents, compact flourescents, halogens incans and an LED array....

the biggest highlights?

incan; 90 watts per hour
flourescent/CF; 10 watts per hour
LED; ONE watt per hour....
 

PhotonWrangler

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I saw that episode also (it's being re-run today). I thought they should've used a Luxeon-based LED lamp instead of that contraption with the 5mm LEDs. I'm not sure that it would put out a useful amount of light compared to the CFL. Interesting episode nonetheless.
 

2xTrinity

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MacTech said:
They're testing the myth whether it's more efficient to leave a light running 24/7 or turn it off when you're not using it....

one of the things they measured was steady-state power consumption in watts/hour

they had metal halides, flourescents, compact flourescents, halogens incans and an LED array....

the biggest highlights?

incan; 90 watts per hour
flourescent/CF; 10 watts per hour
LED; ONE watt per hour....
I just noticed that this show was on. I can't believe that they actually reported energy consumed in "watts per hour", that's absolute nonsense, watts are already energy over time! What their meter was actually recording was 90 watt-hours over the period of an hour. 90 watt-hours/hour is simply 90 watts!

Also, those figures don't say anything about the efficiency of those bulbs, either, as brightness was far from equal between any of the lights tested. The most efficient LED available right now will emit about 80 lumens per watt. This is similar to the efficiency of fluorescent tubes, or metal halide lamps, but at a much greater cost. Unless you need something like a spotlight, or a light that will run easily off of batteries (a flashlight) I still think fluorescent or metal halide is a better way to go.
 

Led_Blind

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I saw that one recently. Yes they only looked at the myth in its pure sence, cycling v's constant on. i cant help but think this was a rushed episode as they tend to extend on on many other myth. A metric on an efficency would be handy.

I have not seen a metal halide direct incan replacement here in Australia, anyone seen one?

FYI the ccfl incan replacments are about 60 lm\w, due to shape output is closer to 50. Its the big flurescent tubes, the ones that take a little time to warm up that are the 80lm\w.
 

drizzle

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I didn't see the episode. Can someone tell me what the outcome was with flourescent lights? Those are the only ones that I ever heard of that it was claimed could, under the right circumstances, use less energy if kept on rather than being turned on and off. Probably also true of Metal Halide I guess.

Based on their other "experiments" I don't trust them to have really done anything to get a definitive answer anyway.
 

Empath

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benchmade_boy said:
also they showed that bulb that has been running for somthing like 105 years. yes i said 105 years. that thing had a huge filamnt through

The Centennial Bulb even has it's own webcam, so you can sit and watch it shine to your heart's content.
 

yuandrew

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Drizzle;

The myth tested was that the startup surge used so much power that it would be cheaper in the long run to leave the lights on than to switch them on and off.

The results of the testing found that the startup surge of many different types of lights was so little that running the same light for "X" ammount of seconds would break even with the startup surge. I don't have cable but there is a site where you can view the particular episode. If I remember correctly, the startup surge of a linear fluorescent lamp (It appeared to be a 2 foot T12 tube with a rapid-start magnetic ballast) used the same amount of power as running the light continously for 23 seconds. I'll have to view it again to find out the results for the other lights.

PhotonWrangler;
I searched around for more on the LED bulb used on the show and it appears that this one LYOBST-172 NF at the bottom of this page http://www.theledlight.com/120-VAC-LEDbulbs.html
was the one they used.
 
Last edited:

Led_Blind

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For all other light sources the startup up power uses the same as .3 seconds of light...

Its MUUUUUCCCCHHHHH beter to turn off the lights, even for 30 seconds :)
 

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