ken wrote: > Ben Okopnik wrote: > > >> To expand on this, there are also LEDs currently in the testing stage - >> not yet in production - that are significantly more efficient than CFLs >> depending on the usage pattern [1] (not three times more efficient, >> however; that would require about 60% efficiency from the LEDs, and >> little beyond fireflies comes even close to that. :) >> >> > > Here is some data I have gathered from various sources regarding light > output of several types of devices. > > 32 watt T8 fluorescent--85 to 95 lumens/watt > standard cool white fluorescent--60-65 lumens/watt > compact fluorescents--low 30's to low 60's lumens per watt, usually > 48-60 > T3 tubular halogen--20 lumens/watt > standard 100 watt incandescent--17 lumens/watt > incandescent night light bulb (7w)--6 lumens/watt > incandescent flashlight bulbs--dismal, less than 6 lumens/watt > > Compare the above to the Lumiled white and colored K2 LED's > the white being rated at 140-175 lumens per watt! > (See; http://www.philipslumileds.com/products/luxeon/luxeonK2) > Not only that but since they waste far less light than the above > sources by putting the light right where it is needed the gain > is much better than the numbers would indicate. > > It would seem just by these numbers that LEDs already outstrip CFLs in > efficiency by a noticeable margin. If we use a low efficiency model of > CFL and a high efficiency LED for comparison in fact we would see a > 200-300% increase in light per watt, best case (for the LED anyhow) > comparison. Even a more moderate comparison is better than a 100% gain. > My experience backs this up. I have seen a LED strip light fixture > running at ten watts that FAR outshone a boat CFL fixture that West > Marine had that was running at about 13 watts (ten watts claimed)! > I'm just curious, since these are specs and not real life, when running CFL from a 12 volt source, what's the real power draw? I gotta believe they aren't as efficient at 12 V as at 110 V nor are they drawing only the wattage shown on the spec for the light. Seems what is missing is a comparison of LED vs CFL in a real world with the efficiencies of fixtures and voltage conversion tossed in. I'm thinking that the LEDs might come out ahead in that case, but that's just an educated guess since there are losses in converting 12V to the high voltage needed by CFL whereas the LEDs voltage requirements appear to be much closer to 12V.
Just curious, Jim. _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
