Fluorescent Lighting for Shop/Garage

[Leon]

Let's see, 22 x 2,700 lumens = 59,400 lumens. That's the equivalent of almost SEVENTY ONE 60W bulbs. Now do you see why that's absolute overkill to the Nth degree? I still think that you'd have plenty of light with 4 fixtures in addition to the two which are already up there, and adding spot illumination where necessary.

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That is only 6 more tubes than in my shop of similar size and that certainly is not nay where near over kill, speaking from experience.

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Power used by 11 fixtures (bulbs + ballasts) would be about a horsepower and a half, 1100W all the time you're in the shop. Even fluor can get expensive to run if there's too much of it.

-------------------------------------------------------------------------------- BS! 22 bulbs only uses 704 watts. At 10 cents per kilowatt hour that is about 7 cents per hour or 56 cents per 8 hour day.

[Leon]

Learn the difference between "Lumens" and "Lux" and your understanding of these matters will likely be better.

[Leon]

[Josepi]

Sorry, I was trying to give you a helping hand hoping you may learn in the right direction.

Since you still demonstrate ignorance , of this difference, in bulb construction, I will leave you with it.

We certainly do not know how much light is being reflected off the walls and objects in the room so the Lux measurement is a moot point. Since we are comparing what we do know, lumens and watts, that is the only measurement that one can use in determining how much light to expect from a particular lamp.

Learn the difference between "Lumens" and "Lux" and your understanding of these matters will likely be better.

[Josepi]

Lux tells the tale. Lumens are only part of the formulae in lighting.

Some smaller wattage bulbs put out higher Lux than others in the same technology. There is a reason for that but since you are "happy with the results" what are you asking here?

----------- The wattage is what tells the tale. Both are the same wattage. I doubt you could tell the difference looking at them side by side.

[russellseaton1]

20' x 25' is roughly 6 meters by 8 meters. 47 square meters. Divide 59,400 lumens by 47 square meters and you get 1254 lux. Which fits in very well with the following chart.

Drawing Work, Detailed Mechanical Workshops, Operation Theatres 1,000 lux Detailed Drawing Work, Very Detailed Mechanical Works 1500 - 2000 lux

I'd say woodworking fits into the detailed mechanical work format.

1254 lux is bright but none too bright. You would still need task lighting for dovetail work.

on 3 switches. One switch would have just two fixtures over

[Gooey]

ps has a bulb: T8, 32w, 5000K, 2850

Looks as if Lumens per watt would be the deciding factor - unless the price of the bulbs varied significantly. But you could determine Lumens Per Dollar Per Watt, no?

[Gooey]

You could buy the 25 bulbs from HD, take two out and compare the brightness and, if not much better than the others, slip them back in the box and return the whole thing - just don't break any in the process!

[Bill]

Larry,

The reputation of your bow saur is renown (had to consult my the-saurus there...)! Have you published a magazine article about it, or a photo or video somewhere?

Bill

[Bill]

That's a pretty good idea. It's one that was evidently well-exploited before I arrived on the scene and it helps gives me a historical perspective. I will keep the lesson in mind for my future use!

Thanks, Bill

[Bill]

helpful perspective!

Bill

[whit3rd]

That's overly pessimistic; firstly, the square law doesn't apply to four-foot-long fixtures until you're over four feet away. Second, the light will reflect from walls and floor and such, it isn't escaping into an infinite void.

End-to-end fixtures (basically a long line of light) is best scaled by an inverse-R law, not by an inverse-R-squared law.

[Bill]

(1) 2700 lumens x 22 bulbs = 59,400 lumens (2) 59,400 lumesn/500 ft^2 = 118.8 lumes/ft^2. (3) If my lights are at 8 ft and I work at 4 ft, then I'm supposed to divide the 118.8 by 4 (or 16, I think--Pi are square), giving 29.7 or

7.425 lumens.

I think it makes more sense to perform the calculations "locally" (in the areas where it matters) and I may do so. But, for the sake of discussion, I assume the 118 figure the one to use in your general guidelines below?

Perhaps you can help me resolve and/or interpret my calculation in (3)?

Thanks! Bill

[Leon]

Jeez, I am probably one of the few left that has not yet plonked you. And then you BS me with non experience as opposed to my experience.

I certainly hope you have nothing that might benefit me in the future as I'll never see it.

[Lee Michaels]

"Leon" wrote

He changes his email addy from time to time. So killfiling this troll is a constant exercise. He was gone for awhile, then he came back. Like a bad smell, he is hard to get rid of.

[dadiOH]

All is fine when you divided by four. Come to think of it that is a bit low as before dividing the figure is for it the light at one foot from the bulb so the fall off to five feet is less than 1/4.

Keep in mind that 70 gives a brightly lighted area. The last time I worked in an office environment was 1958 - the city room of a newspaper - and I would guess that it had about that illumination, maybe somewhat less.

IME, your 22 bulbs will be more than ample. In my 500 ft shop there are 6 bulbs in the center area, and 2 bulbs at each end. The center is just fine but the two ends could use two more bulbs each but are OK for me as there is lots of daylight there.

[Larry Jaques]

What color are your walls, ceiling, and floor painted? If they're not all white, they're sucking up lots of lumens.

What are your ballast figures? You're quoting only bulb wattage.

-- Woe be to him that reads but one book. -- George Herbert

[Martin Eastburn]

Don't forget color.

A yellow color is like the sun and is much brighter than the same in cool or other whites.

Mart> >

[fallen.morgan (at) gmail.com]

I have 6 - 2 bulb 4' fixtures in my 24 x 32 shop and I think its a bit much....My fixtures are 8' high up.

[Larry Jaques]

Like the 500W halogen spotlight over dental chairs and ER tables? Right. We need that kind of light to cut wood.

I wouldn't. And I would truly want to wear sunglasses in that shop.

We all have different requirements, don't we?

-- Woe be to him that reads but one book. -- George Herbert