Somebody school me on fluorescent lamps and ballasts

[mousehunter]

Oh, I like workhorse ballasts .

 

[Random Guy]

Hmmm...that sucks, since I have like 18 of them...but I'm not too fond of the ballasts anyway. Is 8800 lumens the most I can get from the 8' T12 HO fixtures? (110w?)

Also, would I be correct in thinking that if the tubes don't have ANY blackening around the ends, (any kind of tubes) they're probably relatively new?

The ends of Philips tubes do not blacken, they have shields around the cathodes to prevent that.

 

[BatteryCharger]

I remember reading somewhere about putting foil tape on the top half of tubes like this to act as a reflector. Think this would be worth the cost of foil tape on NEW bulbs? If anything would benefit from it I would think the big T12s would, but, the light fixture and ceiling is already painted white...

I thought two T8 4' bulbs would make as many lumens as one T12 8', but that's about 5700 vs 8800 lumens. These old buzzers are becoming more attractive...

 

[BatteryCharger]

I was just reading this article about overdriving standard T8s:
http://www.aquarticles.com/articles/plants/Podio_Overdriving_Standard_Light_Strip.html
I have a similar Sylvania 4x T8 electronic ballast, apparently you can just wire them in parallel and only use two bulbs to double the output.

So if I tried that - how fast am I killing the bulbs? Would it actually double the lumens or less than that? I'm thinking a few of those might be good directly over my work benches...

 

[Random Guy]

I remember reading somewhere about putting foil tape on the top half of tubes like this to act as a reflector. Think this would be worth the cost of foil tape on NEW bulbs? If anything would benefit from it I would think the big T12s would, but, the light fixture and ceiling is already painted white...

I thought two T8 4' bulbs would make as many lumens as one T12 8', but that's about 5700 vs 8800 lumens. These old buzzers are becoming more attractive...

Two F32T8s would be as bright as a F96T12, except for the fact that yours are high output. Normal F96T12s are 75 watts (60 if a Watt-Miser version), and the High Output ones are 110 watts (95 if Watt-Miser).

How well is the space currently lit? If it is currently well-lit enough for you, I would recommend one of two solutions (I am assuming the current fixtures are strip lights). The first is, if you do not mind staying with 8' tubes, would be to go to F96T8/HO. They put out about the same amount of light as a F96T12/HO, but use 86W instead of 110. If you want to go to 4' tubes, either put about 4 F32T8s for each F96T12/HO, or, if your ceilings are high enough where this will not cause excessive glare (F54T5 lamps have a very high surface brightness), put about 2 F54T5/HO for each F96T12/HO. A F54T5/HO puts out about 4600 mean lumens, and consumes 54 watts. Downside of this approach is you will have to go to a supply house to get fixtures and lamps.

In case you are worried about the difficulty of changing 8' lamps, don't be. Yes, you do have to be more careful with them because the are 8' long glass tubes, but you don't have to mess with turning them when you install them like you do with a 4' lamp. On one end of the fixture, the lampholder is a spring loaded plunger. The other one is fixed. You first insert one end of the lamp into the spring loaded lampholder, press it in (compressing the plunger), and then stick the other end in the other lampholder. All types of eight foot lamp are like this.

 

[BatteryCharger]

Well, for now I don't think I'm going to try and "replace" the original lights entirely as I first thought. I was under the impression they were all 60w crap.

Right now I have 176,000 lumens with 20 bulbs @ 8800 each. That would take like 60 T8s to match. :laughing: 8' HO T8s or T5s would be nice, but in the end I'd only save around 500 watts which would take a long time to outweigh the cost of all those ballasts and tubes. I'm not trying to light a whole k-mart. :laughing:

Since my lights are "HO", shouldn't it say that somewhere on the fixture or the ballast? It doesn't say that anywhere but the bulb. I climbed up there and cleaned some of them today, holy crap, what a lot of dust on the top of the tubes. The last occupant painted cars in here so there was a lot of overspray that floated up. The clean ones are noticeably brighter!

 

[BatteryCharger]

What do you think about these Philips "Alto II" T8 tubes?
http://www.1000bulbs.com/F32T8-5000-Kelvin/33929/

I know you said the Altos are bad but I REALLY like the part about "extra low mercury" and "95% lumen maintenance" with a 36,000 hour life. I still have a whole barn that needs to be lit. :ironic:

 

[BatteryCharger]

Hmmm, I was just reading about some Oregon energy tax credits and cash incentives....

It says if I replace one 2 lamp 8' T12 fixture with a 2, 3, or 4 lamp 4' T8 fixture, they'll pay me $30 each! It's not even a tax credit, they just write me a check! :naughty:

 

[HarryN]

Hi, kind of an old thread, but still useful for me at least.

I have recently rented an older work shop with a fairly tall ceiling. It has some 8 ft long fluorescent tube lights about 12 ft off the ground and the bulbs need to be changed out. I routinely change 4 ft ones in the house - 8 ft seems a bit more exciting, so I don't want to do this too many times. I have not climbed up there yet to see exactly what is installed, but I am guessing that it is the older ballast type.

I really like very high CRI / high R9 content light with a lot of lumens. At home we use a mix of tubes in the 4000 - 5000K range to get the really eye opening light we like in the kitchen.

I don't own the place, so I am not going to change out the fixture.

Thanks for any suggestions.