Another lighting question

[Improved700]

I am ready to wire up my lighting for my 26 X 30 shop with 12 foot ceiling. Ceiling and walls will be white painted OSB, and natural color concrete floor. My workplace was replacing their old 2 X 2 fluorescent fixtures with new ones. I grabbed 20 of them. They have two 40 watt U-shaped bulbs in them. My plan was to surface mount these to the ceiling. I figured since the fixtures and most of the bulbs were free, I could mount them, and replace them when they fail or if I cannot find the bulbs.

If I use the 20 fixtures, that's 80 watts per fixture, times 20 fixtures for 1600 watts. Shop size is 750 sq feet, so about 2 watts per sq ft.

I'm thinking this might not be enough. Perhaps I should just scrap the idea, and go with some 4 foot T8 type fixtures. I have looked at a ton of the post's on here about T8's, T12's, CFL's and the like, but no post on these U-Shape lamps.

Not looking to spend a ton of money, but I would like to do it right the first time.

Thanks a lot. This is a great site
Kevin

 

[Charles (in GA)]

Were these units designed to for use in a drop in ceiling? Most likely the ballast will overheat if they are surface mounted to the ceiling. The metal housing of the unit is used to radiate heat from the ballast (most likely a magnetic ballast). Surface mounted will make it impossible to radiate the heat.

While I haven't priced them, I suspect the U shaped bulbs are rather expensive. First time you go to buy one, you will probably be regreting the install.

2 watts per square foot sounds Ok to me, in fact, probably too much.

Charles

 

[Improved700]

Yes, they were from a suspended ceiling installation. Typical office setting. I was concerned with them overheating by surface mounting them. I have not priced the U-Shaped bulbs either, but I would assume there around 7.00 to 9.00 dollars perhaps?
Thanks

 

[nadogail]

U Tubes, this is an example of "one man's trash is another mans treasure". Ask if they have any spare lamps for them, new ones will cost major bucks as compared to straight
F40-T12's.
I have worked for several employers who had U Tube fixyures. Everyone of us maintenance guys hated them. They were relatively difficult to relamp.
You might consider using spacers to stand them away from the ceiling and allow air to circulate if you operate them for hours at a time.

 

[IBEW]

The old saying comes to mind.... you get what you pay for. Want to do it right, spend a little and get the best at lowe's, 8' HO (High Output) fixtures. They cost around 70.00 with lamps per fixture but well worth it. They are great in low temps not like the usual T8 tubes and give you at least 3 times the lumens. If you put 2 rows down your shop, you will be smiling every time you flip the switch. If your painting cars in your shop put a row 4 feet off the floor the length of the shop.

 

[Improved700]

Yes, the HO's really are nice. I have 2 of them in my other garage that is unfinished and unheated, so it's nice to have come on in the wither. If I go witht he 8 foot HO's how many and what pattern would you suggest? Thanks alot.

 

[marty_p]

The guys are right -- drop 'em like their hot! Our office has had some of those start arcing once even a new bulb loses it's hold in an older fixture. $ave up and buy the best you can afford, and you'll never regret 'em. Then sell the rest out of your driveway one Saturday morning!

 

[kbs2244]

Hey...
Free is free.

To keep them from over heating screw through 1x2 runners between them and the celing.
That will give you a 3/4 inch air space above them for some cooling.