Lighting a 15 X 30 area

[FatFenderBowTie]

I am planning to start wiring my shop, the main work area is 25 X 30 with 16' ceilings, inside is finished in white steel. I want to add lighting and am trying to decide between 9 double bulb T12 (3 wide by 3 deep) fixtures and 12 double bulb T12's (4 wide by 3 deep).

I got the fixtures and two boxes of bulbs for free, have enough for either configuration, but do plan on upgrading to T8 or T5 when the fixtures start to give out or as finances permit.

WHAT WOULD YOU DO?

*edit* the title says 15 X 30, but the area is 25 X 30...won't let me edit the title...oops!

 

[pattenp]

If these fixtures are the 4ft long type I'd do the 12 (4 X 3) set up.

 

[Zengineer]

I'd buy T8's from the start and only install once...

9 2-bulb 4' fixtures aren't going to cut it in that space, I'd plan around the 12.

 

[hfdff]

I would have to agree with Zengineer, if you can get the T8's. The T5's are pretty expensive. I bought my T8's from Home Depot and I'm real happy with them. I have a 30x40 metal building with about a 20ft ceiling at the peak, thats insulated and they light the heck out of it.
Here's what I bought http://www.homedepot.com/Lighting-F...splay?langId=-1&storeId=10051&catalogId=10053.
The bulbs I used were 4500k.
I know their is some websites out their that will let you put the size of your building and give you a suggested layout for your fixtures. This what I did when I was trying to decide on what fixtures I was going to use. I thought I still had the website I used, sorry.
When I put the deminsions of my building it suggested that I just needed 3 fixtures down the middle of my building. I went with four and wasn't disappointed I'm pretty sure that I would of been happy with just 3. I hope this helps.

 

[FatFenderBowTie]

Well I have been looking more into this, and due to the number difference between T12 and T5 (even T8) and due to all my wiring being surface mount with conduit, and the power usage of T12 being higher (and needing more breakers), once I add any extra wiring, extra breakers, I believe I am going to go with T5 lighting. Plus the "boss" said what someone else on the site did...just do it once and then you don't have to mess with it again.

I am looking at a 4 bulb HO fixture running a Fulham Workhorse ballast. This unit will run at 216W and 20,000 Lumens, whereas the T8 is 192W and 15,000 - 16,000 Lumens.

The Lithonia 6-Light T8 Fixtures listed are $80 each plus bulbs, the Fulham 4-Light T5 Fixtures are $130 each including bulbs.

And I still think I will go with the 9 fixture set up...3 wide by 3 deep.

Whatcha think?

 

[Zengineer]

T5's are a great choice, you won't regret it. T8's aren't bad either.

With the 16' ceilings, I would go for T5. Less degradation in light, longer life, less maintenance and less energy used. A 16' ceiling can make it a pain to change bulbs.

A 3x3 T8 grid, 2 (32W) bulbs per fixture = approx 70 ft-candles. Good level in a garage.
A 3x3 T8 grid, 6 (32W) bulbs per fixture = approx 215 ft-candles. Crazy bright! (but usable)
A 3x3 T5 grid, 4 (28W) bulbs per fixture = approx 140 ft-candles. Excellent for detail work, older eyes, etc.

If it were me, I'd probably shoot for 4-bulb T5 fixtures in your 3x3 grid, in 5000K. You should be ok with your light distribution but be careful where you place the fixtures. Spreading 9 fixtures over 750sqft evenly may leave you with hot and cold spots... which should be mitigated between the 16' ceiling and painting white where you can...

 

[FatFenderBowTie]

Thanks for that info on candles...I should have also said I am looking at T5 HO fixtures at 54W/bulb. So between that and the semi reflective white steel interior, I should have enough light going with the 4 X 3 layout.

Borrowed one fixture from a friend of mine to see what it will look like, will test it out later to see!

 

[Zengineer]

T5 HO, white interior, and 4x3 is going to be crazy with 4 bulb fixtures... upwards of 320ft-candles. Use 2 bulb fixtures if you are going that route... 160ft-candles is plenty.

 

[FatFenderBowTie]

Ended up going with 6 - 4 bulb T5 fixtures...I wired them so you can fire only 2 bulbs per fixture or all 4, worked out perfectly...