In my new shop there are 8 foot twin T12 bulb fluorescent fixtures with magnetic ballasts. They all are pretty old and some need new ballasts and bulbs. I just won an Ebay auction for 10 new electronic T8 bulb, ballasts. If I can score another 15 ballasts for what I got these for I'll be in business. I need some bulb advice. Do I wany cool white
4100k bulbs, warm white bulbs, full spectrum bulbs, daylight bulbs? It's pretty confusing.
I use cool whites, but it's driven by cost more than anything else. With luck, you can buy them for $3 each, and they do a good job for the intended purpose. For a shop, full spectrum bulbs aren't really a necessity. If you have too much money, they're probably the best choice overall.
As long as the new ballasts aren't regular Slimline (single pin) and the old fixtures aren't High Output (bipin shrouded in an oval)...
Those ballasts will keep what you've got installed now running - but if you are replacing any more, I'd suggest switching over to a F32T8 electronic fixture with mirrored reflectors to squeeze every lumen out of each watthour you buy. They make "Tandem" 4-lamp fixtures that have the same footprint and mount the same as a 2-lamp 8'.
Electronic ballasts will minimize the 120 Hz 'stroboscope' effects that magnetic ballasts give on lathes and other rotating machinery.
And for a shop, I'd buy the clear plastic tube-guard sleeves for all bulbs in open fixtures. Have one screw go -ZING!- flying off, it breaks a lamp, and you get a glass shower...
Cool White is the default and best value, and are just fine for general area lighting. The Daylight or other color temperature lamps with a high Color Rendering Index (CRI) rating are good when you need to match paints and patinas. They blend the phosphors to have an even spread of light across the spectrum frequencies.
'Warm White' 2700K and 'Kitchen & Bath' mainly exist to match existing incandescent lamps inside a house, and are no help for shop lighting.
There are some of really odd colors out there (6400K and higher) that are mainly sold for 'color snobs' and motion picture and TV production work. (They need to match the lamps to the film speed when they're filming inside a house so they don't get an odd color tinge.) And since they don't sell in volume, they charge up the wazoo. If they want triple the price (or more) pass unless you /really/ need them.
Especially with 8 footers, buy lamps by the case. They are more likely to survive the trip, and you'll always need replacements.
The 5400K bulbs match "sun light" and I like the ones I have. The 6500K that Home Depot sells are "sky light" have have way too much blue glare IMHO. I only use the cool or warm whites if I don't have a choice of color temps. I bought my 5400K tubes from MSC in a box of 25 which made the price comparable to the cheapest tubes locally.
And check out aperature bulbs to get even more light headed your way instead of toward the reflector. These have a clear strip down the side facing you, so the UV hits the far phosphors, is converted, and comes out back at you, instead of passing through phospor to get to you. Philips and GE make them, I think.
Also quantum splitting phosphors, if you really want performance. And a hefty price. If they are even available. Or rare earth phosphors, which are available.
I have an eight foot fixture at elevation six feet over my bicycle project, with two Philips F96T12C50 Colortone 75 watt single pin tubes in it. I love it. But we have sunlight coming in on the bike now, and it's 8:17 AM, so that adds a lot.
If you're enclosed, I'd say daylight or full spectrum. Full spectrum is more for plant growth, isn't it? The C number is C100 = daylight, I think.
And stay in a better mood - like outside. The Blue based bulbs are depressing. Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder
While we are on this subject, I'll need to light the new shop one of these days, and "every lumen possible per watt-hour" is high on my list, since I appear to be headed for generating my own power, due to unreasonable connection costs from the local excuse for a utility. As my eyes are getting old and creaky, lots of lumens are also going to be needed, so the typical off-the-grid method of "dimly lit by a few compact fluorescents" is not an option.
I had thought that metal halide might be the best solution, though the 5 minute or so startup is annoying - the shop ceiling is 11-1/2 feet high, which is probably not high enough to run high-bay fixtures; but I have seen a few claims that some of the newer fluorescents meet or beat MH for watt-hours in to light out, and the near-instant start is definitely a good thing...
I just re-fit the nineteen twin tube, t12, mag ballast, 8 foot fixtures in my shop with the t8, quad tube, 4' bulbs, elect ballast retrofit kits. No more headaches from the mag ballast hum, no more interference with the am radio, no more burnt out t12 bulbs seemingly every couple months etc. The 4' bulbs are so much easier to handle than the 8 footers. The best part about the retrofit kit is you don't have to unwire and de-mount the fixture shell.
My shop only has one small window, so I went with the daylight bulbs after trying daylight and cool white side by side in a couple of fixtures for a day. The improvement over the cool white T12 bulbs is really incredible. In addition, I'm hoping the t4 bulbs will last longer than the t12's. This is truly one of the few improvements to the shop that I can put in the "should have done that a long time ago" category.
That works better if you don't really want to deal with buying and hanging MH fixtures. You can also go with dimly lit with a few Metal Halide High-bays for general light in a big barn or shop, and powerful Fluorescent fixtures placed down low over each work location. And separate switches for each area so you only light up the lathe or mill when you are using them.
And the warm up and restrike time delays for Metal Halide or High Pressure Sodium are only a problem if they're the only light source in the room. A 100-watt quartz 'emergency lamp' is a common factory installed option in many high-bay MH fixtures, and it turns itself off automatically when the main lamp starts coming up to speed.
Or put a few fluorescent fixtures in strategic places to handle this, or you can go Total Overkill and put in battery-backed LED EXIT lights over the doors and battery Emergency lights...
Building codes are only a minimum standard, you are welcome to do more. As a matter of fact I usually encourage it, as it's much cheaper to do it right than to do it over.