Looking for advice for shop lighting

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Forum topic by Bill Szydlo posted 02-21-2013 01:26 AM 4585 views 1 time favorited 30 replies Add to Favorites Watch
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Bill Szydlo

67 posts in 2860 days

02-21-2013 01:26 AM

I am finally nearing the finish on my new workshop. The new space is 24’ x 40’ and I have allocated 3 15amp circuits for 3 rows of lighting mounted to the ceiling (9’ ceiling). My plan is to use florescent lighting. Here are my concerns:
1. Is it better to use 3 rows of fixtures with 2 bulbs or to leave gaps and use 4 bulb (4’) fixtures?
2. What type of ballast is better? Electronic or magnetic? The shop will be heated.
3. What type of bulb is recommended? I have read about T8 or T12 but am unsure of the difference.
Thanks in advance, any advice would be appreciated.

30 replies so far

View Manitario's profile


2653 posts in 3056 days

#1 posted 02-21-2013 01:46 AM

Hi Bill, Take a look at my shop pics: My shop is 17×30; I use 2 bulb fixtures with T8 bulbs; three rows across the 17’ width. It is bright, but I am continually adding more lights to the shop, it seems that there is no such thing as too much light. If you are going to go with 3 rows across a 24’ width; I would go with the 4 bulb fixtures.

-- Sometimes the creative process requires foul language. -- Charles Neil

View wiwildcat's profile


58 posts in 2135 days

#2 posted 02-21-2013 01:52 AM

My opinion, for what it is worth,...
T8, with electronic ballast, electronic ballast are typically more efficient. Quality of lights depends on the type of fixture and how much light you need. You may also want to consider T5 lamp fixtures and space them in a row, but with 4ft gaps between the fixtures. You might be able to get by with 11 or 12 fixtures.

-- Wisconsin Wildcat

View crank49's profile


4032 posts in 3144 days

#3 posted 02-21-2013 01:54 AM

Well, the difference in “T” numbers is the diameter of the tubes.
A T12 tube is 12×1/8ths inches in diameter; 1-1/2” diameter.
A T12 historically was 40watts for a 4ft long tube; now they come in lower power 32 or 34 watt versions also.

The T8 tubes are 8×1/8ths inches in diameter; so 1” diameter. and are usually 32 watts.

A newer tube is the T5 HO. It is 5×1/8, or 5/8ths inch diameter and have a power of 54 watts. But, the T5 has twice the lumens of a T8 so you get the same light with 54 watts as two T8, 32 watt tubes. They also have electronic ballasts with a soft start feature so they can be switched on and off with out damaging the tubes.The T5s are so bright they are not recommended for low ceilings, below 10ft, however.

There are LED bulbs coming that look just like T5 flouresent tubes, put out the same light , but last about 20 years and work with dimmers. They are quite expensive right now, but coming down all the time.

I’m in the planning stage of building a new shop and plan to put 4 rows of single T8 tubes continuous from one end of the shop to the other. My shop will be 20 ft wide and 30 ft long. I plan to use either 4 ft or maybe 6 ft tubes just because I hate to handle the long 8 ft tubes.

I would definately NOT install T12 anything in something I’m building today. They are obsolete and won’t be around many more years. IMHO.

View Whiskers's profile


389 posts in 2200 days

#4 posted 02-21-2013 02:00 AM

Another thing to watch for, most common bulbs you see are cool white, which is blue shifted and not as bright as Office or “Professional” bulbs. For a shop especially it is worth the little bit more for the non cool white bulbs for the extra brightness and the more balanced color light.

View HorizontalMike's profile


7770 posts in 3087 days

#5 posted 02-21-2013 02:07 AM

I have six 8ft double bulb T12 fixtures in my shop, for the past 6yr. But as Crank says, if building today, NIX on T12 fixtures. All that being said, I have replaced only two lower wattage 42W bulb in those six years. All of the 75W bulbs are still going strong. My understanding is that the newer generation bulbs should last even longer.

My advice is what ever estimate you come up with for the total number of fixtures that you “think” you will need, DOUBLE THAT NUMBER. IMO, I do not think you will ever regret having the extra lighting.

-- HorizontalMike -- "Woodpeckers understand..."

View djwong's profile


176 posts in 3393 days

#6 posted 02-21-2013 02:14 AM

Definitely use T8 and electronic ballast. These will use less energy. I would not use T5 bulbs, due to glare concerns. Having a white ceiling also makes a big difference in the amount of reflected light from the ceiling. To save on fixtures, you might want to identify the areas you want more light and concentrate fixtures, rather than evenly light the entire shop.

I used an online tool to make an estimate on lighting levels when specifying lighting for my house. I ran the tool on your space 24’ x 40’, 9’ ceiling height, using data from a 2-bulb T8 (32w ea bulb) strip light fixture. The tool calculated 3 rolls of 7 fixtures, will yield ~68 foot-candle at work surface level. Some folks recommend a minimum of 100 foot candle, depending on age and eye sight. If you want 100 fc, you will probably have to go to 4 rows, or use 4-bulb fixtures.

If you are interested, the tool is called Calczone, and I ran it on the Lightolier site, using data from their 2 bulb strip fixture.

-- David W. Cupertino, CA

View AandCstyle's profile


3170 posts in 2430 days

#7 posted 02-21-2013 02:35 AM

I would be tempted to go with the T5 fixtures. Your eyes need a little more light every year as you age. You don’t have to turn them all on at one time if they are too bright. Also, as was mentioned have a white ceiling and walls will greatly improve the brightness in the shop. FWIW

-- Art

View Grandpa's profile


3261 posts in 2848 days

#8 posted 02-21-2013 02:52 AM

I went to the local electric supply place and asked them what they would recommend for my 30×40 shot with 10 ft walls. They talked a bit then said send us your floor plan with the places where you think you want your tools. We have a supplier that will make the recomendations. I did and they did. They recommended 2 bulb fixtures, T12 bulbs, 8 ft long. They recommended 7 fixtures. They also recommended cold weather bulbs because I don’t keep the heat on all the time. They were going to cost me $700 in 2000. I ran across a man that sold me 9 used fixtures that were the regular 8 ft T12 style. I also got 13 boxes of used bulbs. The fixtures and bulbs had been taken out of a supermarket and he bought all of them. I paid him $25 and had to haul them to my house. I put them us and have not had a problem with them. I have replaced 2 or 3 bulbs. These get turned off and on often. More light is better. A person that is 50 years old needs 50% more light to see as well as they did at age 40. A 60 year old person needs 100% more light to see as well as they did at age 40. I might have exceeded that amount. You are limited on the type of lights you install because you need space for the light to spread. I worked at a manufgacturing center and they had 30 or 35 ft. for the light to spreadI had to have mine at the 10 ft line. There are a lot of things to consider. You will need a lot of light.

View wiwildcat's profile


58 posts in 2135 days

#9 posted 02-21-2013 02:54 AM

I would also recommend 4100K lamps with at least 85% CRI for T8. T5, go with 4100K or 3200K temp lamps. If going with shop lights, get a the optional wire guards or a lens on the fixtures. There are some nice surface mounted two lamp fixtures out there too. Also, switch the rows independently or switch every one stagger pattern ( two switches for the whole space). Three circuits seems a but much for the space. Might be able to get by 2, depends on how many fixtures, lamps you install.

-- Wisconsin Wildcat

View TopamaxSurvivor's profile


18380 posts in 3849 days

#10 posted 02-21-2013 05:40 AM

Subject is pretty well covered. Note that T12 and magnetic ballasts are a thing of the past. If you find them, they will be old inventory. T12 is no longer being manufactured. Every one will be converting to T8 or T5 when their bulbs burn out.

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View wiwildcat's profile


58 posts in 2135 days

#11 posted 02-21-2013 07:46 AM

Additional info that may help,

Some basic light layout calcs, mainly rule of thumb and also more specific if you have a spec sheet showing fixture data and coefficient of utilization CU.

What type of fixture are you considering? Off the shelf shop light that plugs in and hangs from ceiling, or a surface mounted fixture where conduit can be run between fixtures, or something recessed like a troffer? Home depot has a decent selection of these lights on display. Mainly Lithonia or Lightolier brand and the lower fixture lines meant for small business or residential applications. Pick a light that you like, get the model number and brand name, then do an internet search to get the data sheet needed to do calculations. Do this for a few fixtures and see which ones work best in your shop, based on initial cost (cost to purchase fixture and lamps and install), lifetime cost (cost to replace lamps and ballast and how often these need replacement based of expected life), power consumption (watts of energy used and if there are local, state, or federal energy codes that need to be met).

-- Wisconsin Wildcat

View Bill Szydlo's profile

Bill Szydlo

67 posts in 2860 days

#12 posted 02-21-2013 02:28 PM

I would like to thank everyone for the extremely helpful information. First some specifics – The type of fixture is going to be ceiling mounted (painted ceiling) with conduit running between the fixtures. Living in MN I wanted to minimize any heat loss through the ceiling. The reason for the the 3 separate circuits (1 for each row of lighting) and 3 switches is basically because I have room in the box. The shop has a separate box from the house.
As I age (currently 56) my eyes are not what they used to be.
Anyway, after reviewing the information I will probably go with 3 rows of fixtures (2 bulbs/fixture), probably T8, and will see how many fixtures fit the space. The more the merrier. The other reason for running all the ceiling lighting with conduit was to afford the flexibility to change or modify it as the need arises.
Thanks again for all the info,

View HorizontalMike's profile


7770 posts in 3087 days

#13 posted 02-21-2013 03:09 PM

NOT ALL T12 are going extinct. My High Output (HO) 75w double 8ft fixtures and bulbs are an example.

Click on below quote for complete article and links:
Lighting Product Phaseouts and Exemptions By Lindsay Audin - October 2010 - Lighting

New minimum energy efficiency standards for lighting are being phased in. Sale and importation of many common types of lamps and ballasts will be discontinued over the next several years. Those responsible for maintaining lighting should be preparing for the changes by reviewing replacement options that meet the new standards, for example, halogen, compact fluorescent, LED, high color rendering index (CRI) T8 fluorescents and electronic ballasts.

The higher standards appear in the Energy Policy Act of 2005 and the Energy Independence and Security Act of 2007, which spell out the changes and when each is to take effect (between 2010 and 2014). Such standards don't actually ban any lamps or ballasts, but the inability of some, such as the typical 100-watt incandescent, to meet the standards will make it impossible for such items to be legally manufactured in or imported into the United States. Immediate impacts are likely to be mild since large existing stocks of such less-efficient lamps and ballasts may still be used or sold until they run out.

Note that some halogen lamps (a more efficient version of incandescent) do meet the new standards, so claims that only compact fluorescent or LED lamps will be allowed in the future have been exaggerated. Bi-pin halogens are unaffected, for example.

While efforts were underway by some major lamp manufacturers to develop incandescents that met the new standards, most of them were abandoned in favor of advancing LED options that offer not only higher energy efficiency but also much greater lamp life.
Which Items Are Affected?

The largest impacts will be felt on:

Standard (A-style) incandescent lamps of 40 to 205 watts.
Many types of incandescent reflector lamps. (See These Reflector Lamps Get an Exemption below).
T12 fluorescent lamps 2 to 8 feet long, including U-tubes and the standard 4-foot, 34-watt units that previously replaced the 40-watt version. About 30 percent of the 4-foot fluorescents sold in the U.S. are still T12s, according to the National Electrical Manufacturers Association.
Some 8-foot single-pin T8 slimline fluorescents with low CRI or low lamp efficacy, measured in lumens/watt.
T8 lamps with low CRI (i.e. ~70).
Magnetic ballasts for common fluorescent lamps, which are 7 percent of the U.S. fluorescent ballast market.

Metal halide fixtures with lamps between 150 and 500 watts are required to meet minimum ballast efficiency standards that took effect Jan. 1, 2009 (see Update on Metal Halide Ballasts on this page). Under a prior federal law, no new mercury vapor ballasts (except specialty types) are to be sold in the U.S. after Jan. 1, 2008. No other high-intensity discharge (HID) lamps or fixtures are affected.

Lots of Exemptions
Most specialty lamps are exempted, as are some specific reflector lamp types (see These Reflector Lamps Get an Exemption on page 64). New federal energy legislation in 2010 was expected to eliminate some of those exemptions, but it failed to pass both houses of Congress.

Among the specialty lamps that will continue to be available are:

Special or rugged service, for example stove/refrigerator lamps, bug lights, plant grow-lights, shatter-resistant, vibration/rough service.
Decorative, such as 3-way, candelabra, globe, colored.

Several types of fluorescent ballasts are also exempted:

Those that dim T12 lamps to 50 percent or less.

Low-temperature high-output (HO) two-lamp units feeding 8-foot T12s, which are often used in billboard signage.

Magnetic ballasts with a power factor below .90 labeled for residential use.

-- HorizontalMike -- "Woodpeckers understand..."

View teejk's profile


1215 posts in 2857 days

#14 posted 02-21-2013 05:15 PM

I have a 40×30 shop, 10’ ceilings. Interior is clad in bright white steel. I ran 2 banks of ceiling mounted T8’s, 4 4’ tubes per fixture, 3 fixtures per bank. Length-wise they are “ganged” together (only conduit I have is the start at the first fixture). That’s 24’ of length per bank which I centered in the space (i.e. 8’ “blank” on each end). Width they are spaced 10’ apart (when I built the shop I had 2×4s run before the steel went up). I got the fixtures at Menards if it means anything to you.

It’s all the light I require even with my tired eyes (same age as yours) but a lot of that is a function of the white steel I think. When I finally get into serious carving work I’ll add more “task” lighting.

Just as aside, I heard that the primary cause for failure on the newer fixtures is poor grounding so pay attention there.

View a1Jim's profile


117272 posts in 3750 days

#15 posted 02-21-2013 05:28 PM

Besides light fixtures part of what assist in making your shop lighter is to make sure your ceilings are painted white,of course folks who drywall their shops are already making their work space lighter. Simple but many folks miss this point with all the other things you have to think about when building a shop,

-- wood crafting & woodworking classes

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