2 Bulb or 4 Bulb lighting Fixtures

[Matthew Curtis]

Does the 4 bulb fixture have an advantage over the 2 bulb fixture? Sure more light, (DUH). No really. Why not just twice as many 2 bulb fixtures? Wouldn't the 4 bulb put more light directly below the fixture, and not necessarily more outward, requiring the same number of 4 bulb fixtures as a 2 bulb to cover the space??

[Kirk Poore]

I used two bulb fixtures in my shop, and spread them out. I think this gives more even light, unless the four bulb fixture is up pretty high. But if you need the extra light, then you don't have much choice.

Kirk

[Ken Fitzgerald]

No advantage really.

The February 2002 Fine WoodWorking magazine had an article written by fellow Creeker Jack Lindsey on proper lighting in the workshop. Excellent article that provides the details for figuring how much lighting is needed and where to place it. The article takes into account age...ceiling height....size of shop.....positioning. It explains the differences in ballasts, quality of ballasts,...lamps....color of lighting......etc. Very well written article.

I used it to design the lighting for my shop and a lot of folks who have visited compliment the lighting.

[Matt Meiser]

When I did mine, I went to a local lighting supply house and had them design the layout using commercial fixtures with their design software. Given the dimensions, ceiling height, wall and ceiling materials, and intended use, they recommended 8' bulb high output fixtures with slotted reflectors to allow some light to go up to the ceiling and bounce back. Not cheap, but worth it as my shop is very bright with no weird spots. I also (knock on wood) haven't had any issues with the fixtures in 7 years, though it will probably be time to relamp them in the next year which I don't think is too bad at all.

I did not spring for the color-corrected bulbs.

[Jack Lindsey]

It's really an issue of the desired lighting level, the need for uniform lighting throughout the shop, the dimensions of the shop, the reflectances of the room surfaces, and the light distribution characteristics of the fixture, tempered with economic constraints. In general you would consider 4 lamp fixtures for high lighting levels in rooms with high ceilings, and 2 lamp fixtures for lower lighting levels or low ceilings. If 4 lamp fixtures are indicated by all means use them. They will provide adequate lighting at a lower first cost since fewer fixtures are need and installation costs will be less.

For most hobby type shops 2 lamp fixtures will be required to provide adequate uniformity of light throughout the space. Since 4 lamp fixtures produce about twice as much light only half as many would be needed and the spacing between fixtures would probably be so great as to create dark spots between fixtures.

The article Ken cited gives specifics on how to determine the required number of fixtures and hints on how to locate them on the ceiling. If you can't find the article PM me with your mailing address and I'll send you a copy.

[glenn bradley]

Jack's article. Good stuff. I have task lighting in addition to more than the normal amount called for.