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  1. #1
    Join Date
    Feb 2004
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    Midwest
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    Btu/h output of 100 watt infra red light bulb?

    Is there a difference between the Btu/h output of a regular white 100 watt light bulb vs. a 100 watt infra-red light bulb?

    I know it sounds like a silly question but it seems like part of the wattage in the white bulb would be used to produce light in the VISIBLE light spectrum rather than IR.

  2. #2
    Join Date
    Dec 2007
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    Frognot TX
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    836
    No matter what color, a watt is 3.41 btu

  3. #3
    Join Date
    Sep 2008
    Location
    Western PA
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    25,760
    I think the difference is that a heat lamp is designed to direct the heat where you want it, rather than dissipate it in all directions.

    1w is 1w is 1w.

  4. #4
    Join Date
    Nov 2008
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    1,673
    "Approximately 90% of the power consumed by an incandescent light bulb is emitted as heat, rather than as visible light."

    So only 10w of your 100w is converted into light.

    "The heated filament emits light that approximates a continuous spectrum. The useful part of the emitted energy is visible light, but most energy is given off as heat in the near-infrared wavelengths."

  5. #5
    Join Date
    Jan 2007
    Location
    central america
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    157
    measure the volts an amps to both multipy, compare?

  6. #6
    Join Date
    Feb 2004
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    Quote Originally Posted by WhoIsThat? View Post
    "Approximately 90% of the power consumed by an incandescent light bulb is emitted as heat, rather than as visible light."

    So only 10w of your 100w is converted into light.

    "The heated filament emits light that approximates a continuous spectrum. The useful part of the emitted energy is visible light, but most energy is given off as heat in the near-infrared wavelengths."
    That's the answer I was looking for. It explains it. And it also explains something else I wondered about - how some incandescent bulbs used less wattage (like the G.E. Misers) and produced the same amount of visible light. Apparently they have a little more than 10% visible light output.

  7. #7
    Join Date
    Dec 2001
    Location
    Chicago, N/W burbs
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    You need a beer or a woman or both
    R2B4BTU

  8. #8
    Join Date
    Feb 2004
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    Midwest
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    Quote Originally Posted by otto View Post
    You need a beer or a woman or both
    BOTH! PLEASE!

  9. #9
    Join Date
    Dec 2001
    Location
    Chicago, N/W burbs
    Posts
    8,004
    Go wait outside in your skivvies.
    They should arrive within the next 45 minutes or so.
    R2B4BTU

  10. #10
    Join Date
    Feb 2004
    Location
    Midwest
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    Quote Originally Posted by otto View Post
    Go wait outside in your skivvies.
    They should arrive within the next 45 minutes or so.
    I tried that, but only the COPS showed up.

    And they didn't even bring me a beer.

    Did I forget something?

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