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We are planning to retrofit an office building with existing fluorescent light fixtures to new 4-ft. LED bulbs

user-3308951 | Posted in Energy Efficiency and Durability on

I work with and electrical contractor who is planning to retrofit an office building with existing fluorescent light fixtures with 4-ft. LED bulbs. What impact will this have on the light bill?

The attempt here is to convert the existing office building into a green building.

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  1. Expert Member
    Dana Dorsett | | #1

    Depends on both what the existing fluorescents are, and what the LED fixtures are, and how each are controlled.

    Dimmable T8 fluorescents under both light level sensing and occupancy sensor control will use a heluva lot less power than un-dimmed LED fixtures that are just left on.

    There is a lot going on with network controlled dimmable LED fixtures these days that can take a huge chunk out of their total power use (and can even be utiliized by automated demand response programs to get paid to dim during peak grid load events.)

    Without sufficient detail it's a bit like asking what the effect will be of replacing a blue car with a green car will have on gas consumption.

    What CAN be said is that the LED fixtures won't incur tube swapping costs, which are considerable over the course of 20 years with any fluorescent technology when looking at the labor-burdened cost of buying, storing, installing, and disposing of fluorescent tubes.

  2. wjrobinson | | #2

    Dana great post.

    Side subject: the choice of words today may need an upgrade. Is labor a burden or in my thinking is it an opportunity? Laboring thru life is the essence of living especially done with a smile.

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