Angryfox        
Results 1 to 7 of 7

Thread: Lumens per watt

  1. #1

    Default Lumens per watt

    Im hoping that one day leds will replace flourescent lights as f. lights give me a headache.

    But was rather dismayed to read:-

    http://www.otherpower.com/otherpower_lighting.html

    which states leds are far less effeciency compared to f. lights.

    Is this informations accurate

    Thoughts anyone ??

  2. #2
    Flashaholic*
    Join Date
    Aug 2002
    Location
    HILLSBORO, OR
    Posts
    1,318

    Default Re: Lumens per watt

    Yes FL lights are more Eff than LEDs, but at what cost - I haven't found them to last as long as advertised, and the color rendition is TERRIBLE

    Here is the sun:

    http://www.inretech.com/pictures/1.jpg

    Here is a FL light:

    http://www.inretech.com/pictures/3.jpg

    You can see that the three large peaks are Blue, Green and Red (Left to right) - but there are *HUGE* holes in the middle

  3. #3
    Flashaholic*
    Join Date
    Apr 2002
    Location
    Boise, ID
    Posts
    2,639

    Default Re: Lumens per watt

    In addition, FL are limited to larger packaging and more complex driving circuitry.

    -Darin

  4. #4
    Flashaholic*
    Join Date
    Aug 2002
    Location
    HILLSBORO, OR
    Posts
    1,318

    Default Re: Lumens per watt

    Yes, there still has to be a ballast - at least the new ones are electronic and do not lose as much as the old ones

    In one of my Spectrometer readings, the light output was almost yellow

    I still prefer Incandescent lighting for a more "purer" White

  5. #5
    Enlightened
    Join Date
    Feb 2003
    Location
    Cleveland, OH, USA
    Posts
    49

    Default Re: Lumens per watt

    I've been lurking for a while - this is my first post.

    Aren't white LEDs basically florescent lights? They use a white phosphor excited by a short-wavelength LED. I had assumed that was why white-light LED flashlights often exhibit blue, green, or violet tinges, just like florescent lamps do.

    Florescent light can be all over the spectrum (pun intended, sorry) in terms of quality; different phosphor formulas and different ballasts give different results. It's true that the cheap tubes and crummy magnetic ballasts used for old shop lights yields nasty color and headache-inducing flicker. But the best phosphors on a nice electronic ballast can give a light that is subjectively very similar to incandescent light, with good rich colors and no perceptible flicker.

    LEDs have made big strides in the areas of power output and efficiency in the last 10-15 years; it's not impossible that they may become a viable large-scale lighting technology one day. I'll be rooting for them!

  6. #6
    Flashaholic*
    Join Date
    Aug 2002
    Location
    HILLSBORO, OR
    Posts
    1,318

    Default Re: Lumens per watt

    Yes, White LEDs use the same technology as a FL tube except that a FL tube is excited by the two wavelengths of Mercury Vapor 245nm and 365nm; whereas the White LED is usually excited by 400-430nm

    The FL powder produces very bright light in those wavelengths that I posted previously, while the White LED phosphor produces these:

    http://www.inretech.com/pictures/4.jpg

    The White LED is "nicer", but it still has some "holes" in the spectrum compared to the Sun or a incandescent lamp

  7. #7

    Default Re: Lumens per watt

    I hate fl lights with every ounce of my exsistance, its just the bastards who own offices insist on them.
    I was hoping LEDs would be a cheaper alternative.As companies only care about cash, leds would take over but it doesn't seem to be the case which I find really disapointing. [img]images/icons/frown.gif[/img]

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •