Shop Lighting Advice Requested

[Brian Kent]

I am about to purchase the first 2 light fixtures for my garage shop. I want to have the whole plan in my head, so each time I get fixtures, it will be a part of a best-possible scenario. (And yes, I know that Jack L. Lindsey wrote the definitive article in 2002. I have tried to glean from his comments without paying $35 for the online Fine-woodworking subscription).

My working area is 18' x 18'. The whole garage is 22" x 22'. The difference is laundry, utilities and storage. White ceiling is 10'. The walls are currently yellow, cabinets black, but those will all be painted white.

I am shooting for 200 Foot Candles at table-height (rather than 100 because I am over 40 years old). According to Jack's formula, (18' x 18' x 200 Cf / 2850 lumens) I will need 22 T8's. I'll use 24. If I use the full garage dimensions I'll still get 147 Cf at work level.

I would like to get 4 of the 6-lamp fixtures by Lithonia Lighting:
http://www.homedepot.com/h_d1/N-5yc1v/R-202193185/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

I'll start with 2 of the fixtures on the side of the shop that includes the hand-tool workbench, table saw, and router table. I'll add the rest when I have time and money for round two.

What do you think? The reflective fixture seems to really help with light intensity. The only down side I can think of is that 6 4-bulb fixtures would risk less shadows than 4 6-bulb fixtures. I'll use 5000K bulbs with at least a CRI of 82 and 2850 lumens.

Thanks in advance for your wisdom and experience.

Brian

[glenn bradley]

Lowe's has a 2-lamp T-8 electronic fixture for about $18. Three of those would be cheaper than the 6 lamp unit you show and allow some flexibility. My 16 or so 2-lamp fixtures started out in a very mathematical pattern to provide even light everywhere. At least four of them have been moved to some extent to eliminate shadows caused by the uniform fixture pattern meeting my non-uniform machine layout. A couple others were added for "corners" ;-)

Just food for thought. The 6 lamp or 4 lamp fixtures would look better but, as you mention, cut back on flexibility. I was going to hang-tough with my mathematical pattern and enhance the light field with location-specific lighting but, those fixtures turned out to be a bit pricey and did not yield as good of a watt to light ratio. I was looking at adding another circuit and redistributing the fixtures to use the "spot" lighting method. Those watts add up fast.

[Brian Kent]

I also need to check the current wiring on the light switch to the ceiling lights. I do not want to over-do the circuit.

[glenn bradley]

I also need to check the current wiring on the light switch to the ceiling lights. I do not want to over-do the circuit.

I should have mentioned that I have two 20 amp circuits off my sub-panel for most of the lights and then a 15 amp circuit off the house main panel that runs 3 fixtures. My logic (although it has never been tested in real life) is that I don't want to be left in the dark if I blow the sub-panel ;-) So, 16 (IIRC) 2 lamp fixtures (32 watt T-8) across 3 circuits. This is well within the circuit's capacity.

[Greg R Bradley]

This is way more complicated than just x number of t-8 bulbs. There is also quite a difference in the light output from a 32w T-8 bulb according to the ballast that you are using.

The good news is that these have Litonia's MVOLT 120-277 volt ballasts and the light output per bulb is excellent. If you are looking at HD and the cheap crap Lithonia's that are built for HD, stick with the ones labeled MVOLT 120-277 and you will get excellent light output per bulb. The last time I looked they tended to be in brown boxes and the even-lower-end Lithonias were in white boxes and labeled 120volt. I was in one HD and they had a lower end Lithonia 120v 2-lamp T-8 fixture for $25 next to an identical looking Lithonia 120v 2-lamp T-8 MVOLT 120-277 for $35 and the difference was obvious. It is well worth paying alot more than the $10 difference to get the higher light output, the better starting in cold temperatures, and the longer life of the MVOLT ballast.

These are High Bay Fixtures and the minimum mounting height is 12' above the floor. Their typical application is to replace the Mercury Vapor lamps in warehouses and are usually mounted at 16-22'. They also cannot be surface mounted! They specify a foot or so but in reality an inch clearance would be fine unless they are going somewhere really hot. These "low-end-crap for HD" skip about half of the steel in the real Lithonia lights and all of the structure at the top of the fixture except the narrow box that contains the ballasts. This is fine if you are mounting your own lights and are careful. They just won't take any rough handling and you have to suspend them carefully because they will twist easily. The real Lithonia equivalent is about $180 in quantity at a commercial supplier that will only sell to businesses. Those reflectors behind the lamps are shiny as a mirror. If you want to spread the light out more for lower mounting, you could dull them a bit, put more holes in them to bounce more light off the ceiling or remove them completely.

I have 4 of those exact lights in my 24x34' garage and they are mounted at 10'. However, they are above my line of sight since most of the center of my garage has the ceiling at 8'. Since these are two complete 3 lamp fixtures internally, I just have one ballast run through a pull switch and normally run them with 3 lights. Then when I want more light, I pull the chain and get more. I have 8 more two lamp and one four lamp fixtures in the garage. These are all the units with plastic covers like you would have in an office since they are down at 8' and surface mounted. A total of 44 T-8 bulbs but virtually never all turned on at the same time.

The Lithonia MVOLT Lights at HD are a great deal as long as you are aware of the difference. HD's website is horrid for trying to get the info you need on these lights and is also full of inaccurate information. I suggest you go in-person. If you only have a Lowes nearby, I suggest you avoid them for their flourescent lights of this type. I also suggest you avoid T-5 lights for your application since they have delays in starting and difficulty starting in cold temperatures. Virtually all serious high bay warehouse lighting is now T-5 because they are run many hours a day and they usually don't get real cold inside an operating business. You can justify the cost of T-5 lighting in energy savings if you are operating 24x7x365 pretty easily.

ETA: I thought I would add that I don't have anything against Lowes over HD. It is just that Lithonia has lots of info about their lighting on their website and HD just sells low end versions of those. Lowes sells Utilitech and there just isn't much info out there that I have found.

[Brian Kent]

Thank you for this information, Greg. Yes, they are MVOLT 120-277. I have a 10' ceiling so 12' mounting is not an option.

[Bryan Wellman]

I agree with what Greg has pointed out completely. The Ibeam lights are really intended for warehouse industrial use. I believe its actually @15' - 40' is their effective range. I would definitley stick with a more traditional shop light for your application. Even at 10' the reflectors in those fixtures are pretty hard on the eyes. I just installed a bunch of these at @ 14' in a welding shop and it was pretty intense if its anywhere in line of sight. And he's also right about the needing them off the ceiling. Even with the reflector, the tops of the lights get pretty darn warm.

I'll be going thru the same situation shortly. Just deciding whether to get nice new fixtures, or do the reballast/relamp with all my old T12 fixtures. Much cheaper to reballast than it is to buy a quality fixture.....and the box store fixtures are definitely not the same unless you're getting their high-end stuff.

[Neil Brooks]

Thank you for this information, Greg. Yes, they are MVOLT 120-277. I have a 10' ceiling so 12' mounting is not an option.

Not a *simple* option, you mean.

Come on, Man. Where are your priorities ?

:D

Neil
Worked 6yrs and -- later -- lived 18mos in Escondido ;)

[Bryan Wellman]

I just clicked on the link you referenced....are these used with a white reflector or their metallic reflector. Because that would make a big difference. All the IBeam hbays that I've installed were the commercial metallic reflected ones. From the pic from the HD website it almost looks white.

OK. Had to look into this more.....(piqued my interest) and found that the metal reflectors are downlighting specific, while the white reflector was designed for widespread distribution. Even at that, the spacing requirements don't change unfortunately.

http://www.lithonia.com/commercial/Fluorescent%20High%20Bays.html?pt=Fluorescent%20an d%20LED%20High%20Bay

[Brian Kent]

Hi Neil. You are right, I could always raise the roof or lower the floor.

Bryan, I also just read on the Lithonia website about the 15'-40' range. I'm sort of back to square one, wondering if any of the 2 or 4 bulb fixtures will last a decent amount of time. I'll use them a couple of hours per day. My basic pattern is that I want to do this right, this time around, because I'll never get around to re-doing it. On the other hand, I am hoping for something in the range of $50-$60 max for a 4 bulb fixture.

Glenn Bradley - I just noticed that was you writing. You changed your avatar again.

One more thing, Neil. I went to High School in Escondido and now live there again, but I was born in Northern Colorado - Greeley and raised in Westminster.

[Bryan Wellman]

My problem as well!! Like I said, I might just do the reballasting thing since I can get quality lamps and ballasts for about $20 per 2bulb T8 fixture. Then its just the time to do it.

Now if you want to go nuts I just went to a specialty store the other day to rewire some demo lights to run new LED replacement tubes!! They fit right into a standard 4' fixture, but you remove the ballast and run the fixture straight 120V. Each bulb has 300 led's and side by side with a new t8 they look incredible. Plus they dont deteriorate like flouresants will and they will last on average 11-12 years. Right now they are $60 a bulb.....but I assume that will drop rapidly as they get mass produced.

[Neil Brooks]

Brian-

I'm in Fort Collins.

NEXT time, we ought to slap hands, as we pass each other by ;)

[Greg R Bradley]

It would appear that my brother has changed his avatar more times than I have posted on this site.

A friend just told me that HD no longer carries the Lithonia basic dual T-8 fixture with the good ballasts. They only have the low end unit for $27 but you really, really want the ones with the MVOLT ballast. They do have a 8' two wide and two long unit available both with the cheap ballasts and the MVOLT ones. The good one is $56. That should work very well surface mounted against a white ceiling in rows to make wiring easy. I would say that is a good solution from HD for a shop with a 10' ceiling.

The High Bay that is at HD has the mirror finish reflector. I can't imagine mounting them a couple inches below a 10' ceiling where they are in line of sight. I looked and the ones in my garage are actually at 11' but in high bays since most of the ceiling is storage mounted on top of the rafters that are at 8'.

Lots of info on light including calculators on Lithonia web site. I looked over the article on FWW and it is very dated. I'm guessing it was out of date when originally published in 2002. After reading it, I was shocked to see the date at the end as I was expecting a decade earlier.

If anyone has quality fixtures that were T-12, it is easy to buy ballasts and bulbs. This is less practical if the fixtures are anything other than 4' as any other size of T-8 bulb costs a bunch more. Good quality 4' T-8 bulbs are about $1 from my supplier.

FWIW, I prefer 3500 degree bulbs in my garage. Don't you want the color and tone of what your working on to match your house? Maybe go to 4100 degree, but 5000 is pretty cold to me.

[Bryan Wellman]

FWIW, I prefer 3500 degree bulbs in my garage. Don't you want the color and tone of what your working on to match your house? Maybe go to 4100 degree, but 5000 is pretty cold to me.

I forgot to mention coloring. LOL Nothing drives me nuts more than walking into a home where somone has put 5100K curly-q bulbs in their living room lamps. I have a few of the 2700K bulbs in the house and you literally can't tell the difference from a standard 60W incadesant. 3500K would be a good comprimise for shop lighting. Better than the "yellow" incadesant, but definitely not the "white/blue" of an over 5000K bulb.

Heres a good color chart if anyone is interested...

[Neil Brooks]

Incidentally, one of the most useful tidbits I learned, when wiring my shop, was to put your lighting on (at least) two separate circuits.

It's great to be able to control what's lit and where.

In the alternative, you can put ALL the lights on two circuits, rather than segregating a circuit to a given area.

In other words ... if your shop uses 20 evenly spaced fixtures, just put 10 on one circuit, and 10 on another.

That way ... you can have the light you need, and save a few bucks -- like ... when you have full daylight coming in, but want to knock down shadows.

[Doug Colombo]

Let me start off by saying that I don't know much about lighting. With that said, in my shop, I used these HD lights:

http://www.homedepot.com/Lighting-Fans-Indoor-Lighting-Industrial-Shop-Lighting/h_d1/N-5yc1vZbvnq/R-202022571/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

Lights have worked great - very bright (with "day light" T8 bulbs). I have had issues with the ballasts going bad after about 2 years (as some of the reviews state), but I called the company and they sent me out replacements (different design) at no cost. My lights are 5 years old now with no issues once I replaced the ballasts. I think the ones sold now have the updated ballasts in them. My ceiling height is 8', but my brother in law purchased the same lights, is using them in his shop with 10' ceilings, and is also happy with them.

[Brian Kent]

Well, I made a decision and then returned it and made another decision. The 6 lamp fixture made for Home Depot by Lithonia is rated on the package as for 10' to 30' high. I bought one with a pack of 5000K bulbs. Then I read more here, returned it without opening, and got 3 of the 8' Lithonias with the good Mvolt ballasts. That gives fixtures for my first 12 lights. I chose 4100K's after reading these opinions. I had never used my new resident / moving discount so they kindly took 10% off. I am now looking for the best arrangement for 3 8' fixtures. That will be all I mount until I can work out a second circuit.

Thanks all for your help. I'll post pics along the way.

By the way, I have never had more than 3 4' T12's and a couple of work area lights, so even 12 T8 bulbs will be such an improvement. I may even be able to see a knife mark on wood!

[Rick Potter]

Hi Brian,

You probably don't remember from your visit, but I used three rows of lights in my shop, with each row on a separate switch. Sometimes I only use one row, usually two, and rarely all three, depending on where I am working. So, I agree with Neil about having them on separate switches.

If this is not feasible, you could put pull chains on some of the lights that may not be needed all the time. Saves moolah.

Rick Potter

[Jack Lindsey]

Hi Brian. Sorry I didn't see your thread until tonight but if it's not too late I’m going to make some recommendations that will save you the 35 bucks for the article and many times that in operating and maintenance costs over the life of the system.

First, 200 footcandles is a lot of light for a woodworking shop. That’s what we use for some detailed inspection tasks, and then only at specific workstations. Typical woodworking tasks call for 50 to 100 FC depending on age, which you mentioned in your post. You imply you are over 40 so I’d recommend 100 FC unless you have some serious visual problems. I’ll work through the calc’s for 100 but if you really want 200 just double the numbers.

You state that the work area is 18 x 18 but the garage is 22 x 22 including laundry, storage, and utility space. All those areas require some light. Not 100, FC but it’s not practical to try and separate a 4’ wide (or two 2’ wide) area from the work area in a small shop so let’s consider the area to be 22 x 22.

Based on the above the number of lumens needed is: 22 x 22 x 100 = 48400. This is the amount of light required at the work surface. In reality only about ½ of the lumens installed at the ceiling will actually get to the work surface over time so you need twice as many, 96800 lumens on the ceiling. If you use a lamp rated at 2850 lumens you need 96800/2850 = 33.96 lamps. It’s really hard to cut a lamp so let’s figure on 34 as a starting point.

You want to use a 6 lamp fixture so let’s see how that works. Thirty four lamps divided by 6 fixtures equals 5.66 fixtures which rounds to 6. The next step is to see how they would fit in the space. If we use 2 rows of three fixtures the spacing would be about 7’ on centers starting 3 ½ from walls for the rows and 11’ between the rows with 5 ½ feet off the walls. I think this would produce uneven lighting with dark spots between fixtures.

A better solution would be 9 four lamp fixtures installed in three rows of three fixtures per row. Like the above option fixtures would be space about 7’ on centers starting 3 ½ feet from walls for rows but the spacing between rows would be about 3 feet from walls on with 8 feet between rows. This will provide better uniformity with little shadowing.

If you want to go a step better use 20 two lamp fixtures installed in four rows of 5 fixtures per row. This permits mounting fixtures in continuous rows which reduces electrical wiring costs. Each row would be about one foot off the wall in the end to end direction. Rows would be spaced six feet apart and start about 2 feet from the side walls.

As far as the fixture type is concerned you have a white ceiling so you really don’t need to spend the extra money on a high efficiency reflector. A plain strip will work just fine.

The 5000K lamp you mentioned will create a very cool visual environment. It will enhance cool colors like blue but will mute warmer colors – yellows and reds. If that’s what you like in your work environment, fine, but if you are building things to go in your house be sure to select finishes and inspect for color in the house.

[Ken Cohen]

Hi--

This has been a very helpful thread as I am about to install 10 4 bulb fixtures in a 42x12 shop (5 x 2 layout).

Question: I am planning to buy the following Lithonia fixture from HD. I had assumed it had the best ballast, but now I am confused. Does anyone know if this fixture contains the MVOLT ballast?

Lithonia Lighting 4 ft. Wraparound Lens Ceiling Fixture

Model # SB 4 32 120 1/4 GESB


Thanks.

Ken

[Brian Kent]

Hi Ken. I find that really hard to determine from the Home Depot website. The info was available on the identification tags on the samples in the store. Good luck to you.

[George Bregar]

Incidentally, one of the most useful tidbits I learned, when wiring my shop, was to put your lighting on (at least) two separate circuits.

It's great to be able to control what's lit and where.

In the alternative, you can put ALL the lights on two circuits, rather than segregating a circuit to a given area.

In other words ... if your shop uses 20 evenly spaced fixtures, just put 10 on one circuit, and 10 on another.

That way ... you can have the light you need, and save a few bucks -- like ... when you have full daylight coming in, but want to knock down shadows. You can also control your lights with a switch as opposed having a dedicated circuit for each group. All my lights are on the same circuit (and nothing else is on it) but a break up the group to my working area and assembly storage area with a separate switch.

[John Lifer]

The 5000K lamp you mentioned will create a very cool visual environment. It will enhance cool colors like blue but will mute warmer colors – yellows and reds. If that’s what you like in your work environment, fine, but if you are building things to go in your house be sure to select finishes and inspect for color in the house. [/QUOTE]

I question this statement as 5K gets you daylight and as we move more and more away from incandescent bulbs, you end up closer to the 5K indoors. To me, daylight bulbs are much closer to natural and brighter. But I guess it is your choice.

[Jack Lindsey]

The 5000K lamp you mentioned will create a very cool visual environment. It will enhance cool colors like blue but will mute warmer colors – yellows and reds. If that’s what you like in your work environment, fine, but if you are building things to go in your house be sure to select finishes and inspect for color in the house.

I question this statement as 5K gets you daylight and as we move more and more away from incandescent bulbs, you end up closer to the 5K indoors. To me, daylight bulbs are much closer to natural and brighter. But I guess it is your choice.[/QUOTE]


When you say "daylight" are you referring to daylight at 7 am in smoggy Los Angeles, high noon in Denver, or on an overcast, snowy day in Chicago? Daylight is dynamic. It changes constantly depending upon sun's elevation in the sky an a multitude of environmental factors. In fact, daylight frequently ranges from 1800K to nearly 10,000K, thus daylight in the home will follow that color temperature range. When incandescent lighting is used in the home consider that the color temperature of incandescent lamps is in the 2700K to 3000K range. Also note that the sun is a blackbody radiator and incandescent lamps approximate one within the visible portion of the spectrum so the present a smooth transition within the color spectrum. Fluorescent lamps have high spikes and deep valleys in their spectral distribution. When selecting finishes to enhance colors it is best to do it under the light source to be used.

[Brian Kent]

Jack, I will soon actually have an opinion about 4100K, but for today I celebrate my lack of experience.

With multiple fixtures with multiple T8 bulbs and multiple MVOLT electronic ballasts, will the high frequency flicker create a strobe effect? Or, since there are so many high frequency cycles going on at once, will I actually be able to see that my router bit or table saw blade are moving?

[Greg R Bradley]

No flicker, very quiet, very little interference.

We are moving away from the normal residential incandescent temperature of 2700K and flourescents of that temp may look yellow to someone in a house with very modern lighting. I use 3500K in my garage shop and home. 4100K will look more industrial than residential but seems pretty reasonable to most people for both.
I used 5000K in a medical manufacturing facility and it looked fine in the clean room and control areas. It got pretty strong reactions from SOME people in the offices.

ETA: There was some motivation to use 5000K in industrial lights since those lamps put out more light. In any decent lamps today, 3500-5000K will be the same light output. The earlier phosphors that make more blue light are only used in the very low end lamps. Decent Phillips T-8 at HD are about $30 for a box of 25 at this point.

[Jack Lindsey]

Jack, I will soon actually have an opinion about 4100K, but for today I celebrate my lack of experience.

With multiple fixtures with multiple T8 bulbs and multiple MVOLT electronic ballasts, will the high frequency flicker create a strobe effect? Or, since there are so many high frequency cycles going on at once, will I actually be able to see that my router bit or table saw blade are moving?

The choice of color temp is simple. What do you like? This is your shop so only your opinion counts.

Strobe effect is a function of the lamp operating frequency and the decay time of the phosphors (the light producing element of the lamp). While strobe may be noticeable at the 60 hz operating frequency of magnetic ballasts it seldom causes a moving blade to appear stationary due to the decay time of phosphors. The phosphors don't go from zero light to full light or full light to zero instantaneously. They ramp up and drop off so strobe is minimized. It may be annoying but is seldom dangerous. The danger is significant with clear HID lamps installed on a single phase electrical distribution system but you aren't using HID. Electronic ballasts operate at much higher frequencies, usually in the 20 to 40 kilohertz range so strobe or flicker aren't a generally a problem. While some individuals are bothered by flicker from 60 hz systems I've never heard anyone complain about it from electronic ballasts.

[Brian Kent]

I got the first fixture up today - learning curve time so the rest should go much faster. I am already a happy camper! :D

The area bathed in light is beautiful. I can hardly wait to work with wood and hand tools and big machines that I can actually see! :cool:

Thanks everyone. I am using 4100K bulbs and I like it.

Brian

[John Gustafson]

Hi--

This has been a very helpful thread as I am about to install 10 4 bulb fixtures in a 42x12 shop (5 x 2 layout).

Question: I am planning to buy the following Lithonia fixture from HD. I had assumed it had the best ballast, but now I am confused. Does anyone know if this fixture contains the MVOLT ballast?

Lithonia Lighting 4 ft. Wraparound Lens Ceiling Fixture

Model # SB 4 32 120 1/4 GESB


Thanks.

Ken
For what it's worth, I did some dredging around in the Lithonia site. This fixture is in their "residential/light commercial" area www.lightahome.com . The GESB is their code for General Electronic Ballast. I guess one could drill down deeper but the short answer is it does not seem to be the "better" ballast. I'm interested because I have a 42 x 30 three car garage under construction. Whether it ever see's a vehicle inside is open to question. LOML has already named it "the man cave" but lighting and wiring is on the top of my list after the siding and roofers are gone. My concern with flourescents is light output in cold weather. SE VA does not get real cold but I have seen output drop off in unheated garages. Hopefully performance has improved over the years.

[Ken Cohen]

Regarding the MVOLT ballast, I went to HD today and confirmed the comments from an earlier post:


The good news is that these have Litonia's MVOLT 120-277 volt ballasts and the light output per bulb is excellent. If you are looking at HD and the cheap crap Lithonia's that are built for HD, stick with the ones labeled MVOLT 120-277 and you will get excellent light output per bulb. The last time I looked they tended to be in brown boxes and the even-lower-end Lithonias were in white boxes and labeled 120volt. I was in one HD and they had a lower end Lithonia 120v 2-lamp T-8 fixture for $25 next to an identical looking Lithonia 120v 2-lamp T-8 MVOLT 120-277 for $35 and the difference was obvious. It is well worth paying alot more than the $10 difference to get the higher light output, the better starting in cold temperatures, and the longer life of the MVOLT ballast.The 4 lamp unit with MVOLT is clearly marked MVOLT and is approximately an additional $10 per unit. The others are GESB ballasts which the above poster describes.

I guess the only question is whether anyone knows the performance capability of the GESB ballast since it is not referenced in the catalog.

Thanks to all for the help.

[Brian Kent]

The stated difference besides the multiple voltage is the fact that the MVOLTS work at -20° and the others at 0°. I chose them for possible durability difference and the "High Output" designation. That all may not be necessary here where it never gets below 28° in the coldest winter night.

[Greg R Bradley]

When you look at the model numbers in Lithonia's catalog and the model numbers on the Lithonia lights at HD, they don't seem to line up quite perfectly. In addition, it seems some of the model numbers on the bins at HD don't always match the numbers on the boxes, although most do match. The info on HD's website was only confusing to me and I spent quite a bit of time researching lighting for several customers. It appears to me that Lithonia is making lower end versions of their "contractor" line of the industrial fixtures for HD and changing the model numbers around a bit.

I can tell you that the I Beam fixture in the original post is exactly the same in function as the ones that came from the electrical wholesale place when we installed a bunch in a warehouse. They seem to be missing a bunch of the upper housing and are much flimsier than the real thing. They have the same ballasts. They wouldn't take rough handling but if you are careful installing them, they should be fine. We installed 180 and didn't have a bad ballast. I can't recall needing a ballast replaced in the 4 years following where I would have probably heard about it.

In the 2x2 fixture that Brian ended up getting for surface mount, the lamp is more likely to be the same as their regular stuff. I can't see them making a lighter gage metal just for HD but who knows. An 8' fixture needs two people to install, anyway. Once it is mounted to the ceiling, who would care if the metal is thinner?

On Lithonia, if it has the industrial ballast, it will say "T8 MVOLT 120-277v" on the box. If it says "T8 120v" on it then it does not. I believe there may be different levels in the residential ballasts but am only guessing about that from the different wiring diagrams.

I think John is onto something above that Lithonia has a separate website for home stuff with the GESB ballast, whatever that is. I can tell you from my experience, I would be happy to pay ALOT more than $10 extra to get the industrial ballasts. I hate hum, noise, electrical interference, and stuff that breaks after a few years. I also don't want a delay when it comes on, difficulty starting when it is cold, or a big delay before it reaches full brightness. I have one $17 "shop light" in my garage and it makes more noise than all the rest combined.

[Kevin Gurney]

I am getting ready to wire and light my shop. All this information has been very helpful. One question I have is in regards to ceiling height. If my ceiling is higher, how do I calculate for that? I am converting my pole building into a shop and it has vaulted/sloped ceilings. I would like 100 foot candles at the workbench height throughout the shop. The shop is 36ftx24ft.

Thanks

[Ken Fitzgerald]

Kevin,

If Jack Lindsey doesn't reply to your question, PM him. He's a retired lighting engineer IIRC. He wrote a fantastic article in Feb. 2002 Fine WoodWorking magazine about Shop Lighting. It was an extremely thorough article.

[Jack Lindsey]

I am getting ready to wire and light my shop. All this information has been very helpful. One question I have is in regards to ceiling height. If my ceiling is higher, how do I calculate for that? I am converting my pole building into a shop and it has vaulted/sloped ceilings. I would like 100 foot candles at the workbench height throughout the shop. The shop is 36ftx24ft.

Thanks

Kevin, it depends on several factors including the reflectances of the walls and ceiling, the mounting height of the fixtures if they are mounting a uniform distance from the floor or the height of each row of fixtures if they are suspended a uniform distance from the ceiling, and the light distribution characteristics of the fixtures. Also should consider the height of the ceiling at the walls and at the peak and are there trusses or other structural members that would create shadows. I need that info to offer a reasonable opinion. For the reflectances just tell me what colors. I don't expect you to have photometrics on the fixtures but what lamps and fixture type are you considering? If the fixture and/or lamp don't appear to be appropriate I'll offer suggestions.

[Buck Williams]

Kevin,

Here's a link to a simple calculator using the room cavity ratio method, that allows you to plug in the dimensions of your space. As well as dimensions you'll need to know your lamp lumen output a 32watt T8 fluorescent equals about 2800 lumens. Under the "Variables" section in this calculator it lists "Coefficient of Utilization". This refers to the general reflectance of the room, e.g. white walls, ceilng, and floors. I've always guessed at that category, .50 or less would be a darker less relective area. It should get you in the ballpark.


http://sea.siemens.com/consultant/docs/DA_ZCR_Calculator.xls

[Brian Kent]

A year and a half later - I think I have a ballast failure. three of the four bulbs are dim and one is out. Bulb replacement doesn't change it. I assume I just need to buy and install this $30 item: GE ProLine T8 Multi-Volt 4-Lamp Replacement Ballast…or should I get something else since the last one lasted 1.5 years.
I am very happy with the light output of the 4x4 MVOLT fixtures and I still plan to add two more in the hand tool and lathe areas.

[Jack Lindsey]

Brian - most GE electronic ballasts have a 5 year warranty. Call them at 1-888-432-2552 for help.

[Brian Kent]

Thank you Jack.