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Thread: Questions for those that converted T12 4 foot fluorescent fixtures to LED.

  1. #1

    Questions for those that converted T12 4 foot fluorescent fixtures to LED.

    Thanks in advance for any insights.

    Is there a huge difference between frosted vs clear light emitting diode (LED) bulbs?

    Can one discern the difference between a 84+ color rendering index (CRI) bulb and a 90+ CRI bulb?

    Is there a huge difference between a 4000 Kelvin (K) bulb and a 5000 K bulb?

    What's your favorite brand of 4 foot LED bulb?

    I need to replace thirty T12 bulbs. One has been flickering and humming. I started really looking at them the other day and they are all getting a dark ring on the ends, some more than others. Also, it's obvious they are all not putting out the same amount of light or the same color for that matter. I'm very comfortable performing the required bypass ballast wiring, the single end power or double end power bulbs will work.

    As far as I can tell the frosted bulbs cost a little more than the clear ones. And the higher the CRI, the higher the cost. The warmth of the light, 4000 K vs 5000 K, doesn't seem to figure into the cost though. The frosted bulbs come with a beam angle of 140 degrees, the clear with a beam angle of 120 degrees - I don't see that the beam angle makes much of a difference since the fixtures are mounted 8 feet up.

    I did the math (or tried to) and it looks like my return on investment (ROI) on the LED bulbs is 2-3 years based on my estimated light use vs. if I went new T12 bulbs. I.e., new T12 bulbs are roughly a third of the cost of LED bulbs, but they cost a little over twice as much to operate and electricity cost is most likely increasing for me as the electric company wants consumers to fund their planned wind turbine venture.

  2. #2
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    It may be easier to use bulbs that get power from both ends. With those type the tombstones do not matter. many tombstones are linked so the two pins are electrically connected. If you have those type and your bulbs are connected at only one end you have to replace half the tombstones.
    Bil lD

  3. #3
    Mike,

    There is a sticky thread about shop lighting in Work Shops. I'm sure there is a lot of valuable information about led shop lights in there.

    Bill

  4. #4
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    8' is likely too low even for frosted bulbs. The narrow pattern will create challenges to get even light and you may have glare problems. It really depends on your layout but you will be getting more light directly down and a lot less coverage. I am assuming you don't have any lenses on your existing lights and they are bare bulbs in the fixtures. 8' over a bench Is fine.

    8' is WAY too low to even consider clear lens replacements. I tried some at 10' and they were nasty. We have glare problems at 12' when you are in line with a row of fixtures. I'm very happy with clear lens when hung at 15'. Then the narrower pattern actually helps.
    Last edited by Greg R Bradley; 04-13-2019 at 11:24 PM.

  5. #5
    I replaced the 12-8' bulbs in my shop.Ceilings are 10' and the bulbs are frosted. Heat range is 6500. . Wiring was changed to have connections at both ends. The difference in light was DRAMATIC. And no flicker when its cold. I'm now going to do the 4' bulbs in the kitchen but have to decide on heat range first as my wife wants a softer light.

  6. #6
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    I just installed some 4 foot LED lighting in my small shop and love them! From Lowe’s - Lithonia dual strip light fixtures and cost 45 dollars. Rated 4000 or 4500K depending on where you look on box, 80 CRI. Nice bright white light compared to the old T8 lights. Not much more energy efficient at 50 watts but so much better to work under. This is with just under 8 foot ceilings yet the design allows for a nice wide spread of light. Couldn’t be happier.
    Not sure what the bulbs cost for what you are considering but these entire fixtures are fairly reasonable.

  7. #7
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    I replaced 24 T12 4-footers in my shop with frosted 5K's. They are eight feet off the floor. Love them! Really bright. I got the ones that do not use the ballast, because it is the ballasts that are the problem. My fixtures are 4 bulb and I had to jumper them together after I took out the ballasts. A little bit of work, but worth it.

    As for temperature, the lower temp bulbs will be blueish in tint. I wouldn't use anything less than 5000 Kelvin. The higher the temperature, the closer to natural light they will be.

    I purchased mine from greenlightdepot.com. I think I paid $7 each. That was 2 years ago. Cheaper now, I think.
    Last edited by tom lucas; 04-14-2019 at 8:24 AM.

  8. #8
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    Quote Originally Posted by tom lucas View Post

    As for temperature, the lower temp bulbs will be blueish in tint. I wouldn't use anything less than 5000 Kelvin. The higher the temperature, the closer to natural light they will be.
    I think you meant HIGHER temperature are more bluish. Lower temps start to emulate incandescent around 2700 degrees. Cooler temps look warmer in color.

    Here is what I used when I relamped all of our troffers at church, about 6 cases IIRC. https://www.1000bulbs.com/product/192824/PLT-10848.html
    NOW you tell me...

  9. #9
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    I am confused. I have a bunch of 4ft lighting fixtures. Mainly 40 watt T12, plus one or two fixtures rated 4x 32 watt T8.

    Who makes the brightest LED's bulbs (giving off more light than I presently have per fixture)?

    I can always use more light. Brighter the better for me even in my home. (Cataracts have been taken care of.) I am guessing my house is visible from space in the evening.
    Last edited by Bob Landel; 04-14-2019 at 10:51 AM.

  10. #10
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    For the few T12 fixtures I retained in my shop, I used the Feit replacements from Costco and they shine just as bright as the LED fixtures from the same source. I chose not to do any re-wiring or ballast removal at the time. These lights are SUBSTANTIALLY brighter than the original T12 fluorescent tubes were, even when new.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  11. #11
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    "Only those who have the patience to do simple things perfectly will acquire the skill to do difficult things easily. Friedrich von Schiller (1759-1805)

    Woodworking since 1972

  12. #12
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    I installed seven 48" four bulb T12 florescent in our 24x24' shop 16 years ago. They were commercial grade Lithonia wraparound fixtures and have served us well.

    It's always been a chore to keep all 28 bulbs going at the same time. Everything is fine for a while but then it seems like one fixture or another needs a bulb replaced.

    Recently, some of the ballasts have been acting up and some bulbs don't come on at first or at all. Most have their original ballasts but one has had them replaced several times. I don't think they make them as good as they used to.

    There are two ballasts per fixture at $20 buck each so $280 to replace them all. I briefly considered replacing the fixtures with those LED shop lights sold at Sams and Costco that many woodworkers seem to like.

    I did some research and found a ballast bypass LED replacement bulb from Hyperikon. Basically, you remove the ballasts and wire the existing tombstone sockets directly to the incoming power. The new bulbs are T8 size but fit in a G13 tombstone for a T12. After removing the ballasts, it's really no different than installing a standard light fixture.

    That's it. Fixture upgraded with energy efficient, long life LED bulbs. It takes less than 30 minutes per fixture for the conversion start to finish and I work slowly around electricity (even when the breaker is off). Total cost for 28 bulbs was $290 or about the same as replacing the ballasts. They are rated for 45,000 hours with a five year warranty so I hope to have carefree light in the shop for a long time. Even better, Hyperikon doubles the warranty to 10 years when you register them.

    I'm super pleased with my "new" shop lights and wanted to share. No affiliation at all with this company. Just a new fan.

    FYI - I went with the 4000K Daylight Glow and like the clean light.

    They're available through Amazon or direct from the manufacturer.

    https://www.amazon.com/gp/product/B00S5O83BG/
    Last edited by Joe Adams; 04-14-2019 at 3:17 PM.

  13. When setting up my shop, I was replacing 6 incandescent lights with 30 4ft led lights. I utilized the Lithonia 4ft shop light fixtures and the 95CRI T8 bulbs from Waveform lighting. The bulbs are supposed to be compatible with ballasts and direct wire as well as voltage from 120v - 240v. The ballasts in the fixtures turned out to be incompatible, so had to bypass to do my initial testing.

    I tested both the 4000k and 6500k lights. My ceiling is roughly 8ft. With only a single fixture to test, the 4000k seemed a little warm. The 6500k light appeared harsh, but more clear.

    I went with the 6500k. With enough fixtures, the harshness seems to have gone away and feels very natural. I do not know for sure if this is due to the high CRI rating or if the cooler temp requires more output to look natural. Whichever it is, I am very pleased. There is a 5000k version of the bulb available, but was not released when I started testing.

  14. #14
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    I do not know what country you live in but in the USA many power companies will come out and do a light survey and recommend how many fixtures and what type you should be using. They do this to reduce the power you need. there are also government programs that will pay rebates for installed energy efficient fixtures.
    It seems backwards but the power companies make more money if they get their customers to save energy at peak demand times so they do not have to pay for expensive peaking power.
    See what your local and national government has to offer.
    Bil lD

  15. #15
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    You can't compare wattage for equivalent light. The LEDs will be more efficient (same lumens, less power consumption). You have to compare lumens. I'm using 18 watt LEDs and I believe they are brighter than the 40W T12's they replace.

    I struggle to understand why anyone would get the ballast compatible bulbs, just to save a few minutes on installation only to have the ballast fail later.

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