How do I switch from fluorescent tubes to LED bulbs?
December 2, 2017 1:13 PM   Subscribe

I live in the condo that time forgot, and I have fluorescent tube lights. How do I determine what kind of bulbs I need, and if I can in fact just replace the tubes with new LED tubes?

My condo was built in 1978 and has the original light fixtures in the ceiling. I have a pair of tubes ( approx 36") recessed in my kitchen ceiling, and another fluorescent tube (23") above my range.

Googling around the internet it appears that I may be able replace these bulbs with LED bulbs without having to rewire the ballasts, but I'm totally confused by the specs on LED bulb websites. I found a couple of discussion boards that made me even more confused. Have you swapped out your fluorescent tubes? Please let me know what I should be looking for in regards to ballast type and bulbs.
posted by Maude_the_destroyer to Home & Garden (5 answers total) 1 user marked this as a favorite
I had fixtures about that age, and I was able to keep the ballasts and replace the bulbs with some LED tubes I got at Home Depot (Philips InstantFit T8, mine were the long kind). I did have some intermittent flickering problems with one of the ballasts.
posted by RobotVoodooPower at 1:45 PM on December 2, 2017 [1 favorite]

There are two problems with finding a simple replacement. Built in 1978 means that you likely have older T12 (1.5 inch diameter) tubes and an older magnetic (instead of newer electronic) ballast. You probably won't find a drop in replacement.

The simplest replacement would be a ballast-bypass type LED tube, but this requires some minor rewiring inside the fixture, which you may or may not want to tackle yourself.

But don't despair. Your fluorescent tubes are already quite energy efficient compared to incandescent lighting. Right now, your fluorescent tubes, all together, are only using the equivalent of one traditional 60-watt light bulb. If you could replace them with LEDs, you might save just 20 watts.

Currently, if your fluorescent tubes are turned on for eight hours a day, they would cost about $18 a year in electricity. With an LED replacement, you might save $6 a year. If you average less than 8 hours a day, the savings would be even less.
posted by JackFlash at 3:40 PM on December 2, 2017 [1 favorite]

Bring an old bulb into Home Depot or Lowes and ask them what kind of replacement you need. Get them to show you the fancy daylight fluorescent tubes.
posted by gregr at 3:54 PM on December 2, 2017

If your ballasts are original it's likely they contain PCBs (IE: if the sticker on the ballast does not say something to the effect of "PCB Free" assume PCBs). This isn't a significant hazard but you must take special care when disposing. Consult your local hazardous waste people.

Your ballast should say what type of florescent tubes it works with if you go that route. You'll have problems if you attempt to use T8 tubes with a ballast designed for T12 (short bulb life, flickering, potentially reduced ballast life).

A 3' Ballast Bypass LED is going to pull 10-12W. Doing a ballast bypass is the best for energy reduction and reliability. Bypassing the Ballast is a job easily within the reach of any electrically minded handyman.

Carefully inspect your existing fixture before buying anything; it's pretty common for fixtures that age to have damaged tombstones (the bits the tube fit into).
posted by Mitheral at 8:35 PM on December 2, 2017

The ballast is a good thing to get rid of, if you can find a reasonable non-ballast LED bulb to replace it with. LED's work differently than fluorescent lights, and the old ballast primarily works to consume additional power when used in conjunction with an LED bulb. However, manufacturers are aware that many of these are going into use as retrofits, by non-electricians, so there are also bulbs that work with ballasts, and bulbs that work either way.

The job of rewiring a fixture isn't too bad, assuming that you can get at the ballast. Older lights usually make this fairly easy because the ballasts fail frequently. Some newer lights with electronic ballasts can make this very difficult. There is usually a door or other mechanism to get at the ballasts in older fixtures. You should open this up and inspect it, then maybe watch some YouTube videos about rewiring fixtures for LED's, to see if this is within your skill set. I had a 9 year old doing it, supervised.

If you do not feel comfortable doing this, or cannot easily bypass the ballast, don't fear, as others have pointed out, you're still much more efficient than incandescent bulbs.
posted by jgreco at 7:26 AM on December 3, 2017

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