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Thread: Cri and kelvin

  1. #1

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    Hi I went to Homedepot today (Canada), and I was planning to buy some fluorcent bulb. But the problem is, none of the bulbs said anything about CRI nor Kelvin rating. It shows only the lumens and watt !

    My question is, how can I find CRI and Kelvin rating? Is there a calculation to get them ??

    I saw only Phillips brand ! [img]http://www.**********.com/iB_html/non-cgi/emoticons/new/smile_k_ani_32.gif[/img]

  2. #2

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    Kelvin is heat. Kelvin is 173+C (degree of celcius currently). I am not sure how to convert watts to heat. But a watt is a unit of work. So if it does __ watts in light work there must be aforumla for how many watts in heat work it does but I am not sure.

  3. #3

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    I believe he is talking about color temperature in Kelvin. From what I have learned, bulbs in the range of 5500K-6500K generally work best for plants.

    Home Depot usually only labels bulbs as warm white (the worst, I think around 2700K), cool white, and daylight. You want to try and use cool white or daylight when possible, since they are closer to 5500-6500K.

    What kind of bulbs are you looking for? Tubes or compact fluorescents? Often one manufacturer will report the color temp while others will not. It seems like Philips usually provides this information on their smaller tubes that are individually packaged.

    If you are interested in compact fluorescents, check out this thread:

    http://www.**********.com/cgi-bin....t=17820

  4. #4

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    I am looking for compact fluorescents. So you suggest to get cool white or daylight. How'bout the watt and lumen ?

    I'm wondering which brand and model u guys are using .. [img]http://www.**********.com/iB_html/non-cgi/emoticons/new/smile_h_32.gif[/img]

  5. #5

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    I see. I don't use growlisghts but I do have a few that were labeled "plant lights" that I will use eventually.

  6. #6

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    If you want a bulb from Home Depot, I would recommend a Fluorex. This light is 6500K and takes 65 watts with about 5000 lumen output. However, it does require a special fixture; the bulb will not fit in a normal socket. The fixture and bulb together cost $40 where I live, but I have seen others find it as low as $20-$30. Look in the outdoor lighting section, it is marketed as a flood light. I have had great success with this light.

    If you require a bulb that fits in a normal socket, Home Depot has 17 watt daylight bulbs that put out about 1100 lumens, and 42 watt "warm white" bulbs which put out about 2600 lumens but at a bad color spectrum. If you want a high output bulb that fits in a standard socket, go to the link I posted previously.

    -Ben

  7. #7

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    Quote Originally Posted by [b
    Quote[/b] (Treaqum @ May 13 2005,7:04)]Kelvin is heat. Kelvin is 173+C (degree of celcius currently). I am not sure how to convert watts to heat. But a watt is a unit of work. So if it does __ watts in light work there must be aforumla for how many watts in heat work it does but I am not sure.
    Actually, if you don't mind me correcting you (I'm a physicist):

    Kelvin is temperature: deg K = 273.15 + deg C

    A watt is a unit of power, not work; it is a joule/sec. You can use google to convert joules to BTU, or calories, or whatnot.

    The power rating of a fluorescent lamp is not directly convertible to the lumen output; although that depends on power, it also depends on the construction of the lamp.
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