Can I have too much fluorescent lighting?

[Wilbur Pan]

One more data point:

I ran through a similar set of calculations for my basement workshop. I painted the walls and ceiling white. The calculations told me that I needed 8 4 foot 2-bulb T8 fixtures for a 11' x 20' shop. Like you, I had limitations, and could only put in five fixtures. I still wish that I was able to fit three more in.

However, one easy way to get around this is by setting up task lighting.

[Steve Rozmiarek]

Greg, you've got some good solid opinions so far I think. 24x24x9.5 garage for me, 7 8ft T-12's. I hate shadows in the shop, and I have some tall equipment. Works quite well. I personally doubt you could get a room too bright with flourescents, unless they covered the ceiling.

[Jack Lindsey]

Greg, it looks like you are on the right track based on the parameters you have given. White ceilings and walls are a definite plus.

Your calculation looks correct, calling for 7.14 fixtures but remember, this is only an approximation based on industry averages. Given more specific information about your shop I could perform more precise calculations but for a 400 square foot shop the differences in the approximation and a precise calculation would be meaningless. I might come up with 6.98 or 7.18 but in either case 6 fixtures (3 rows of 2 fixtures/row) fits in the space so the layout would be based on 6 fixtures.

Is this too much? Not unless you have very sensitive eyes and like to wear sunglasses in an office or supermarket.

I do recommend, though, that you change the arrangement of fixtures in the room. Locate the outside rows, those closest to the walls, about 3 feet from the walls, and the center row in the center of the room. This accomplishes two things: it puts more light near the walls where we typically locate machines, thus reducing shadowing; and it lightens up the walls to create a brighter work environment.

[Lit Jones]

The basement shop I'm setting up is 12' by 15'. I put in 5 two foot by 4 foot 4-bulb troffer type fixtures plus one 2 foot by 2 foot, evenly spaced throughout the shop. I was shooting for six 4 x 2's but overhead heating ducts required that I reduce one of the fixtures to a 2 x 2. This equates to 22 four foot T8 bulbs. I find the light output to be perfect. I certainly would not want any less, and don't feel I need any more.

I bought my Lithonia GT8 2x4 troffer fixtures from Home Depot. They included the bulbs and whips for their $44 price. A good deal in my book. I easily mounted them directly to my overhead joists and they look great with their diffusers. They really dress up the shop and provide an even light with no shadows anywhere. They turn on instantly and are completely noiseless.

I put 8 of these troffer fixtures into my 18x22 shop, and it seems like the right amount. I can see everything easily, and it is not overly bright.
http://picasaweb.google.com/litlouis...48005807182770

[John Eaton]

My shop is roughly 13x23 and I use 4 four foot double bulb fixtures for general lighting. It's not incredibly bright but I use task lighting at pretty much every machine and above the benches - the task lights can be turned on when the machine is in use or when I'm at a bench. I've found the other lighting to be plenty for the space - the real trick I think is to space things so you minimalize shadows - much more important than glaring lights in my opinion. I use daylight bulbs in the general lighting and mix both blue and yellow lights to attain a more natural balance - I've found that too much of the same type of light tends to tint everything so you don't get a good approximation of how the finish is going to look sitting in a room, where daylight comes through windows (I'm in a basement with no exterior windows).

-- John

[Rick Moyer]

It's been four months since this thread was started and I am now ready to start MY lighting project. I am curious if those who were doing this last fall(and others) have completed their lighting and their thoughts on it now.

I also have about a 20X20 shop, white drywall ceiling and white OSB walls. I plan on using T-8's. What do you think about 6 8' fixtures or would you go with 8 8' fixtures (four-bulb)?

I've read the threads about separate circuits, switches, color, etc. I'm mainly concerned about how much lighting to put in.

[Jim O'Dell]

My shop is 20 X 24. I have 22 T-8 bulbs in it now, with 3 more 4' two bulb fixtures scheduled to go in. It is just fine for my 53 year old eyes. I also have some added task lighting for different machines, but so far, don't use them often. Jim.

[glenn bradley]

I'm right on track with Jim; 21 x 31 shop area, twenty-two 4' T-8 lamps along with eight T-12 lamps in non-critical areas like near the hardware cabinet and jig cabinet . . . Oh, and over the washer/dryer. The difference is so significant that the remaining T-12's will probably go first chance I get.

[Chris Padilla]

In my 20' x 20', I have 3 rows of 2 sets of 8' 4 T8's each. Did you get that?

So I have 8 T8s per row...24 T8s total as the main ceiling lights. I love it...nice and bright...and quiet, too!

[Don Bullock]

I posted a picture of the shop half of my 24' x 40' shop/garage building ---

See: http://www.sawmillcreek.org/showthread.php?t=95520

As the previous post stated, the shop has 32 4 foot t8s.

i still haven't moved in the shop yet. Our contractor is using the building for tools and supplies for another project. I can say, however, that the shop is bright at night. As shown in the second picture the ceiling and walls are painted gloss white.

[Dave Lessley]

I have a 24 x 30 shop actual inside 23x29 I have not hung them all up yet but will have 4 rows of 3 8' T8 fixtures or 12 total 8' fixtures. I only have the first fixture in each row installed as I am waiting to do my ducting before I hang the rest. I have a white ceiling and walls. I mounted them directly to the ceiling without reflectors. The lighting at that end of the shop is not overly or glaringly bright. I almost think I should have added a 5th row but will most likely handle the exceptions with task lighting. I also have each bank of lights on a separate switch. I like the idea of having pull chains so I could further control lighting as I see fit down the road.

[Chip Lindley]

THREE ways to KNOW if you have too much light:

(1) You have to wear sunglasses at night....
(2) You have a deep suntan in Minnesota in February....
(3) The ATF raids your shop thinking POT grows there....

[Rick Moyer]

Consensus seems to be about 15-20 sq.ft. per bulb. I have about 440 sq.ft. so 20-30 bulbs would probably do. Because of where my OH doors hangers are, I will not be able to run three rows of lights so I'll likely try to fit in 6 or 7 8'ers, or mix in a few 4'ers somewhere.

[Sonny Edmonds]

If green things begin growing in your shop....
You may have too much light.
If you come in from a day in the shop and have a dark tan....
You may have too much light.
If the DEA raids your house because you are using ten times the electricity of your neighbors....
You may have too much light.
If you require dark safety glasses in the shop....
You may have too much light.

[Dave Chrudimsky]

My shop is also 20x20 and I'm using eight fixtures, in other words 32 bulbs. It's not too much light.

-chrud