Effiency of modern tube fluorescents

Discussion in 'Electrical Forum discussion & Blog' started by Homeownerinburb, Oct 9, 2012.

  1. Homeownerinburb

    Homeownerinburb New Member

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    I'm looking for a good on-line reference to compare older fluorescent to newer.

    Specifically I am looking to describe how inefficient old 8' T12 single pin tubes are compared to modern 4' T8s, or whatever else could be swapped in.
  2. Chad Schloss

    Chad Schloss Member

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  3. Homeownerinburb

    Homeownerinburb New Member

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  4. jimbo

    jimbo Plumber

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    Go to philips.com or sylvania.com, look for the online general catlog. Lots of info . But the watts tell the story.
    Comparing 4 footers.....tyically F40T12 40 watts. Some of the watts consumed by the filament in the rapid start bulbs. T8 bulb...typical was f32T8...32 watts, yielding approx. same lumens as a 40 watt t12. That is a 20% savings, plus often a more efficient ballast. Nowadays, you can get a 28 watt or even 25 watt 4'T8, with almost same lumens. That is significant. And the newest, T5, are even more efficient.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    The quantity and type of florescent phosphers make a big difference in the light quality, quantity, and longevity.
  6. hj

    hj Moderator & Master Plumber Staff Member

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    To address the original question, if the phraseology is correct, an 48" bulb of any kind will not "swap" with a 96" one.
  7. jimbo

    jimbo Plumber

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    Really????? I was just using 48s as an example, because I did not have the details for the 96" at my fingertips!
  8. Homeownerinburb

    Homeownerinburb New Member

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    Yes. Thanks. I might never have figured that one out.

    My expectation is to remove all the equipment and replace it with new. So a three tube T12 8', with old ballasts, replaced by an 8' fixture with 4 4' tubes, T8s.

    Nearly the same lumens? Many less watts? I have seen 40% savings cited, sounds pretty attractive.

    I was looking today at some 8' T5 with four 4' tubes, way high output. Amazing output, but a bit power hungry.
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    This is a guess, but to charge the entire length of an 8' tube probably isn't as efficient as doing the same for a 4' tube, so two 4' tubes may end up having higher lumen output, but at higher parasitic losses. What the balance is on this, I don't know.
  10. jimbo

    jimbo Plumber

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    All three types of bulbs mentioned...T5,8,12 are available as "regular", HO (high output) and VHO (very high output.) The latter are often found in outdoor lighting, sighage, etc and not commonly used indoors. Factors such as cost and inconvenience and $$$ of inventorying 8' bulbs might suggest using an 8 foot fixture which is actually 2 4 footers. Such fixture are commonly available.

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