Question (WOODWEB Member) :
I'm planning to convert my T12 florescent fixtures to T8 fixtures. I don't know if I should go with the conversion kits or all new fixtures. Has anyone done this? Are there any pro or cons either way? Did the conversion make any noticeable difference in you electric bill?
Forum Responses
(Business and Management Forum)
From Contributor B:
I made the switch last year with new fixtures. After the fact I looked at each new fixture and realized there was as much wattage being drawn by the new T8’s as was from the old T12’s. Just add the wattage of four T8 4' tubes vs. two T12’s at 8'. It was basically the same if not a bit higher on the T8’s.
What you do get though is additional light for the same amount of wattage. What you also get is the eventual lower cost of T8’s as T12’s are phased out and the tubes become more expensive. I also paid more for the fixtures with the top reflector shields. That seems to help reflect more light downward.
Depending on how many fixtures you have you want to investigate T5. Again they’re brighter than T8 as T8 is to T12. It’s more expensive but there are retro kits by Lithonia to go into four footers and they’re easy to install. I helped a Library swap out about 330 T12 fixtures to T5. We followed up on electrical usage and once we were done we'd reduced consumption by 20%. This is for a 25,000 square foot building with 350 or so fixtures (I didn't work on all of them). That's an impressive figure to me. Retro-fit kits were about $175 if I recall correctly, bought in batches of 100 or so. Either way it's a good fix. You'll be glad you did it. Use your head, if you don't know how to wire then hire an electrician.
If these are simple shop lights hanging from ceiling you're in pretty good shape. If they are inset into a suspended ceiling it's a different deal but not bad, just a retro kit of some kind, which must come from a wholesale company probably. If it were me I'd buy four footers and hang. You'll get as much light out of a four foot T5 as you did an 8' T12, more actually.
Don't get the least expensive bulbs you can get. Be aware there are different color bulbs so look for a 3800k color, also called 825 I think. That’s a good question for your wholesale man. Wrong color light is annoying. You ought to change your bulbs out after about two years probably, or at 50% of their life expectancy in hours as they dim considerably after that.
Just get on with it - you'll be glad you did. I echo the comment above about going to T5 if you have to change fixture. The main advantage of T8 besides lower upfront cost is you can retro into existing four foot T12 fixture and still use the existing tombstones to insert bulbs. If you have eight footers this doesn’t apply. T5 uses different tombstones so not worth redoing all that, just get a different fixture.
I've talked to our electric wholesale supply house and they will calculate the lighting levels provided by the various options and help me with the paperwork for the utility rebates. Not all areas of the shop need the same level of lighting. Most of the shop currently has two tube 8' T12's on 10' centers end to end. I'd like to keep the 10' CC distance and not have to redo everything. I found out that the 8' T8 lamps cost a lot more per foot than the 4' ones. To keep long term lamp replacement cost down I'll either end up converting the 8' fixtures to 4' or have to pay a lot more for an electrician to hang all new.
