You must have a lot better eyes than me then. Six 23w cfl bulbs put out about 8820 lumens. Divide that by your 400 square feet and that’s only 22 lumens per foot, not very bright.
For 400’ I wouldn’t recommend any less than 40,000 lumens or 100 per ft. I would also recommend a high color temperature a least 4k.
I use all cfl’s in my shop, they were cheaper to buy that t12 or t8’s and are far more reliable than the t12/t8 ones I tried.
PMB
Phil,
I can't verify the fact that the CF bulbs do not last long if they are used in very cold environments but the granary where I get my water softener salt has around 20 of the CF bulbs lighting one of their storage warehouses, the guy that helps load the salt told me that most of the bulbs won't make it through the Winter and that the savings in electricity is minimal when it comes to the labor and CF bulb costs for replacement. They are considering going back to the old tungsten bulbs.
David B
[quote=Phil B;1077324]
For 400’ I wouldn’t recommend any less than 40,000 lumens or 100 per ft.
Agreed, Phil, but that is at the workplane. To accomplish this you must put about twice that on the ceiling, or about 13 two lamp 4' fixtures.
I just bought (not installed yet) seven 8' four-bulb t-8 fixtures and (28)5100K bulbs for my 420sq ft shop so I should be good I think. Walls are painted white (OSB) and ceiling is painted white drywall. Sound about right to you all? I don't have access to Jack's article.
Rick, that's how many bulbs I will eventually have in my shop, and it's slightly larger than yours (480 sq. ft.) I also have some task lighting, but rarely use it except at the BS and DP where the fluorescents are lacking. I am using the CR86 5000 bulbs. I'm comfortable in there, and my eyes need a lot of light. Jim.
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No, I'm not an electrician. Any information I share is purely what I would do myself. If in doubt, hire an electrician!
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I have seventeen two tube 4 foot fluorescent fixtures in my 550 sq. foot basement workshop, which has a nine foot ceiling and flat white painted gypsum board walls..... the fixtures and tubes were the cheapest I could find and have served well since installed 25 years ago.....I recall researching "how much lighting" is good for workshops and believe I found an article in FW that gave guidance - I was surprised at the time how much was recommended...... I may have gone one or two fixtures over the guidance, figuring that I might as well 'max out' one 15 amp circuit; there is a bit of concentration of the fixtures in the area of the workbenchs and the tablesaw, mainly to remove any shadows ...... I deactivated a couple of fixtures (just by twisting the bulbs so their prongs no longer make electrical contact) in a wood storage area and I added simple "gooseneck" magnetic or clip on lights to my drill press and bandsaw for tightly focussed task lighting.
It's bright but not blindingly so unless I exit the shop late at night into a dark night; it's nice to be able to see a lightly marked line, the grain of piece of wood or find a dropped screw anywhere in the shop.
One thing to remember if you intend to "grow old" with your workshop is that eyesight does deteriorate with age (smiley)
good luck
michael
Sounds about right, Rick. You didn't give the dimensions of your shop so I can't comment on the layout but the general rule for spacing between rows is that the distance from a wall to the first row should be 1/3 to 1/2 the distance between rows. For example, if your shop is 20' wide and you have three rows of fixtures running parallel to the 20' wall you would locate a row 3' from each wall, and have 7' between the rows.
Jack, can I scale this kind of information to my shop?
I have a 30X30 foot shop with 11 1/2 foot ceilings. The shop is all painted semigloss white. I have 12 dual tube 4 foot T-8 fixtures, and 4 100W incandescent bulbs in there now. If I scale the square feet and the shop sizes I would need 28 fixtures. Am I really that far off the recommendation?
Wood'N'Scout
Jack,
Until I can get ahold of the article...
What kelvin rating do you recommend?
I have just bought my first batch of T-8 lights but havent really decided which bulb yet. Can you think for me here?
thanks!
Steve - that sounds close enough. Just make sure to locate the two outside rows clase to the walls. I'd go about 3 feet from walls with about 8' in between rows.
Calvin - color temperature is strictly a matter of preference. For comparison:
3000K is about the color of a 100 watt incandescent lamp.
Warm, strong in red. Good for inside the home.
3500K is neutral, between warm and cool.
4100K is the same as cool white.
5000K is somewhat cool.
6500K is daylight fluorescent, not the same as sunlight.
very cold appearance. Somewhat bluish.
My preference for a shop is 4100K but that's just my preference.
For my shop, I got a total of 40 (5500K, 100W equivalent) CFL from Walmart for a little less than $0.92/ea. I used 18 for the shop (yes...I actually wired up 18 lamp holders since I have easy access to the ceiling), spacing one every 3ft.
At 1600 lumen per bulb in a 10x20ft workshop, I ended up with about 144 lumen/sqft - making it very bright to work with. Assuming only 50% get to the eye-level surfaces, it's still 72 lumen/sqft. The total cost is less than $120 with 22 CFL left for replacement.
Having 18 CFL sticking out of the ceiling looking kind of cool, too. It's a bit unorthordox though.
Haven't heard much here about the screw-in flourescents! I put a 100 watt in my carport and it was so bright I removed it and used a 60 watt! Whats the negative of this light in the workshop?
Nothing to add to this string. I am severely under lit in my garage/shop. One 4' two-lamp florescent fixture, and the garage door opener light to supplement. When I need more lighting, I'll turn on the portable lamp, with a 60W bulb installed, and face it up. It's like a dungeon in there. I definitely need more lighting.
What amperage is needed for all this lighting you all speak of? And are they on a dedicated line? No sub-panel (yet) in my shop. Hopefully one day soon.