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  • Confusion in LED vs. CFL

    I was installing a CFL, 85 watt and was going over the specs, I got a little confused. I had a plan to buy 100w LED. But comparing both the specs, I got confused. The specs are as follows:

    [B]Crompton Greave 85 CFL:[/B]

    VOLT: 220-240V
    COLOR TEMP: 6500K

    [U]LUMEN: 5525[/U]

    [U]CURRENT: 650mA[/U]

    --------

    [B]100W LED[/B]

    VOLT: 32-24V
    COLOR TEMP: 6500K

    [B]LUMEN: 8000-9000 [/B]

    [B]CURRENT: 3500mA[/B]


    LED are supposed to eat less current. No?

  • #2
    Originally posted by mcc View Post
    I was installing a CFL, 85 watt and was going over the specs, I got a little confused. I had a plan to buy 100w LED. But comparing both the specs, I got confused. The specs are as follows:

    [B]Crompton Greave 85 CFL:[/B]

    VOLT: 220-240V
    COLOR TEMP: 6500K

    [U]LUMEN: 5525[/U]

    [U]CURRENT: 650mA[/U]

    --------

    [B]100W LED[/B]

    VOLT: 32-24V
    COLOR TEMP: 6500K

    [B]LUMEN: 8000-9000 [/B]

    [B]CURRENT: 3500mA[/B]


    LED are supposed to eat less current. No?
    No not at all. They are suppose to be efficient measured in Lumens/Watt.

    The CFL uses 143 watts and produces 5525 Lumens which = 38.6 L/W which is extremely low for a CFL with normal being about 60-70 L/W

    The LED uses 112 watts and produces 8000 Lumens which = 71 L/W which is above average for LED lights.

    So what all this means if the CFL you are looking at is really a bad design.

    Sent via Droid
    MSEE, PE

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    • #3
      Another difference between LED's & CFL's is the light angle. CFL's radiate light in all directions, unless you put a reflector on them. LED's produce light in one direction, unless you use a diffuser on them. Then the led watt-lumen factor goes way down.
      Spotlight - LED
      room light - CFL
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      • #4
        Originally posted by mcc View Post
        I was installing a CFL, 85 watt and was going over the specs, I got a little confused. I had a plan to buy 100w LED. But comparing both the specs, I got confused. The specs are as follows:

        [B]Crompton Greave 85 CFL:[/B]

        VOLT: 220-240V
        COLOR TEMP: 6500K

        [U]LUMEN: 5525[/U]

        [U]CURRENT: 650mA[/U]

        --------

        [B]100W LED[/B]

        VOLT: 32-24V
        COLOR TEMP: 6500K

        [B]LUMEN: 8000-9000 [/B]

        [B]CURRENT: 3500mA[/B]


        LED are supposed to eat less current. No?
        You can't compare the mA values of the two lamps when you are using two different voltages. If the 100 watt LED ran at the same voltage as the CFL (220 - 240V) then it's current would be around 440mA compared to the 650ma.
        Last edited by SunEagle; 12-25-2012, 06:44 PM. Reason: spelling

        Comment


        • #5
          Alrite. I just wanted to know, how much time, the LED with following specs, can stay on at a 150Ah Battery.

          Forward Voltage:32- 35V
          Output power: 50W
          DC Forward Currect (IF) : 1750mA

          Comment


          • #6
            Originally posted by mcc View Post
            Alrite. I just wanted to know, how much time, the LED with following specs, can stay on at a 150Ah Battery.

            Forward Voltage:32- 35V
            [COLOR=#ff0000]Output power: 50W[/COLOR]
            DC Forward Currect (IF) : 1750mA
            Well with 35 volts applied the power is really 62 watts, not 50, and you did not specify the battery voltage so I will assume 12 volts. To 50% DOD a 12 volt 150 AH battery can run the LED if fully charged roughly 14 hours.

            Sent via Droid
            MSEE, PE

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            • #7
              And how did you calculate that? I'm having hard time n calculations

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              • #8
                Ok Ok. You mean:

                [B][LIST][*]150Ah / 50 = 75Ah[*][*]62 watt / 12v = 5.1A[*][*]75Ah / 5.1A = 14.7 hours?[/LIST]
                [/B]

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                • #9
                  Originally posted by mcc View Post
                  Ok Ok. You mean:

                  [B][LIST][*]150Ah / 50 = 75Ah [*]62 watt / 12v = 5.1A [*]75Ah / 5.1A = 14.7 hours? [/LIST]
                  [/B]
                  You got it. But there are some line and inverter losses, so 14 is a better estimate.
                  MSEE, PE

                  Comment


                  • #10
                    Originally posted by Sunking View Post
                    No not at all. They are suppose to be efficient measured in Lumens/Watt.

                    The CFL uses 143 watts and produces 5525 Lumens which = 38.6 L/W which is extremely low for a CFL with normal being about 60-70 L/W

                    The LED uses 112 watts and produces 8000 Lumens which = 71 L/W which is above average for LED lights.

                    So what all this means if the CFL you are looking at is really a bad design.

                    Sent via Droid
                    I agee with above, it's correct calculation!LED can have70-90 Lm/W, depending on whether the LED fixture is with len, cover or not
                    We just concentrate at LED lighting

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