Garage Light Fixture Quality

[David C]

I am in the process of purchasing 42 (2) tube 4' T-8 light fixtures for my garage shop.

The fixture type recommended are the simple sheet metal housing with (2) bare tubes, no lens or shroud.

I have internet searched Lowes, HD etc and there are many many fixtures that seem to meet this criteria and the cost ranges from near $20/fix to $80/fix +.

I do not want interference with an FM radio and ambient temperatures are rarely lower than 32F.

How do I evaluate which fixture to purchase? $20/fix is over $800 to me. Cheap equipment can cost more than the original purchase cost.

Can the sheet metal housing be too thin in any of the mfg fixtures?

Can the installed ballast be of a very poor grade?
Note that the web pages for these show very little more than a photo and very general specs.

Is there much of a difference between fixtures and how do I determine this other than through unit cost?

How do I determine the installed ballast in a $30 Lithonia fixture.

I have read a lot of past posts on this issue and while there has been considerable discussion I could never find a conclusive response to these questions.

Additionally a lighting design post by one of the GJ contributors and a post at Sawcreek Mill were imeasurably helpful in designing my lighting. The GJ poster also turned me on to Insteon switching which will save me a lot of money and trouble. I am gratefull to both GJ and SCM and their contributors.

David

 

[pattenp]

Just make sure whatever fixture you decide on that the ballast is listed as residential or residential/commercial. The ones just listed as commercial will most likely give you some RF interference.

 

[wyliesdiesels]

Make sure the fixtures are properly grounded. And with that many fixtures you will have to put them on multiple circuits!

 

[JoeFin]

You find almost no difference in the sheet metal housing. the thickness is mandated by code.

The quality of the ballast is really what your buying.

 

[James-W]

Have you considered using CFL's instead of fluorescent tubes? I have 12 of the CFL's in my garage, each one draws 23 watts (pretty sure) but they are equal in lighting to 100 watt incandescent bulbs. I have found them to be a very nice alternative to regular florescent tubes.

 

[David C]

Thank you all for your reply's.

I understand the residential ballast RF issue but the lights I have found on the itnernet, AMZ, Lowes, HD do not mention whether the lighting is residential.

Is there a way to determine the ballast type and it's quality before purchase if you don't actully buy it at the store?

I think the metal housing is required to be grounded. What beyond that would constitue "well grounded"?

Thanks for the idea on CFL but for some reason I want the fixtures close to the ceiling and have the idea that light from a long tube is more diffuse than from the point source of a CFL.

 

[cybrdyke]

A residential ballast is designated as Class B, by the FCC. Look for that rating on the ballast label, package or spec sheet. Ask your supplier to show you the ballast in the fixture and then google it to make sure.
The type of fixture you are describing is called a 'strip' fixture. Call it a 2 lamp 4' strip.
The radio interference issue is real, especially in block and concrete buildings like garages. You can mitigate the issue some by making sure that radios and lights are on different circuits and that radio antennae or coax cables are not near the lights. Even then, sometimes you can get some static. There are RIF filters available to put on fluorescent circuits, but their effectiveness is ummm.....uncertain.
CD

 

[jp_over]

Great questions, subscribed!

 

[JimD1]

David,

How did you decide you need 84 4' fluorecent bulbs for your shop? My shop is small, only 14x24 but I am debating between 8 32W tubes and 8 CFLs, probably 23W. The CFLs will give me about 400 lumens/m2 and the tubes about 700. I checked online for recommendations and they say 500 lumens/m2 is good for an office. 250 is OK for normal house lighting. 750 is recommended for a mechanical shop. I'm trying to decide. I would put the CFLs in cheap $10 fixtures that hug the ceiling and protect the bulbs. I like their better appearance and bulb protection. But they might not give me enough light. But I had 6 similar bulbs in my last shop and thought it wasn't too bad, a little dim but usable.

 

[Falcon67]

I used the $40 8' 4 bulb HD Lithonia fixtures. No radio problems and a lot less wire to run and work to mount than the 26 4' fixtures I thought I wanted. I've installed 3 bulbs in the last 3 years and had no - zero - ballast fails.

I also have 3 "task light" Lights of America (bottom barrel cheap Walmart) 4' shop lights. Those are 3 and 5 years old, no problems with them either.

 

[David C]

JimD1,

This is how I decided upon my lighting fixtures. I read many posts here and on SawcreekMill. I don't have the exact URL for the SCM post but if you can't find it I'll search for it and post it for you.

Here is the calc.

My garage 24'x48'=1152 sq-ft

1152x100FC(foot candles)x2(factored efficiency)/2800Lumens/2lights per fixture

Results in 41 fixtures.

My floor plan layout worked with 42 fixtures, I increased the fixtures in the shop area (slightly) and reduced (slightly) the fixtures in the garage portion.

One of the forum members here, one that contributed to lighting design questions before he kind of got flamed, suggested multiple switching, such as walk through lighting and various levels of lighting. He also recommended insteon switching. I am grateful for his posts, used his ideas, and intend to install insteon switches. I will wire and contol the lighting so I don't need to switch on all lights at once. If I don't need all of the lumens I won't turn on a portion of the light fixtures.

If your implied question is "is your design overlighted" my answer at this point would be, I don't know. I read a lot of posts on this issue and the posters I gave credit too seemed to make sense. I used their recommendations. I am currently installing the exterior siding and it will likely be months before I get the lighting fixtures installed so I can't comment on the results.

I purchased fixtures designed for residential light commercial to reduce RFI, per the above recommendation, and I will probably use the above suggestion about isolating circuits.

David

 

[AP514]

I guess im way under lit....my Garage is 1624sf 10'ceiling and I only have 6 - 8' (2 bulb T12 75w 5500 lumes) from HD .

 

[black00lightning]

I used the same formula and it calculated 34 - 2 bulb x 4' fixtures for my woodworking workshop (960 sqft). However, since the plan is to eventually convert the space to a guest/carriage house, I didn't want all those fixture hanging down (12' ceilings). So, I've decided to use 6" recessed cans with 45 watt cfl bulbs (2800 lumens). If the conversion occurs down the road, it will just a matter of swapping to much smaller bulbs. I also have the option of using 85watt cfl bulbs with 4000 lumens although y hey will drop below the fixture.

 

[Thumper68]

I used the same formula and it calculated 34 - 2 bulb x 4' fixtures for my woodworking workshop (960 sqft). However, since the plan is to eventually convert the space to a guest/carriage house, I didn't want all those fixture hanging down (12' ceilings). So, I've decided to use 6" recessed cans with 45 watt cfl bulbs (2800 lumens). If the conversion occurs down the road, it will just a matter of swapping to much smaller bulbs. I also have the option of using 85watt cfl bulbs with 4000 lumens although y hey will drop below the fixture.

I just installed 10 6"cans in a cabin I was working on and per the owners request we used the LED kits, I can't tell you how much better the light was from the LED's like night and day, plus they are dimmable.

 

[black00lightning]

I just installed 10 6"cans in a cabin I was working on and per the owners request we used the LED kits, I can't tell you how much better the light was from the LED's like night and day, plus they are dimmable.

I've look at LEDs but at this point, there are not any readily available LEDs that will match the light output of cfls. As "brighter" LEDs become available, we plan to replace the cfl with LEDs.

 

[GAR64]

I realize that I am also "underlit". I only have 5 4' T8's. My garage is 36x30. I would think that 2 or 3x what I have would be plenty. 8x seems like it may be more than necessary.

 

[davetulk]

I found it is more about the bulb than the fixture. I use these bulbs http://t.homedepot.com/p/Philips-4-...66585?storeId=10051&langId=-1&catalogId=10053

It's amazing the difference a bulb makes. I find these are good for garage/work space. Very white and bright.

For the fixture I used http://t.homedepot.com/p/Lithonia-L...ip-Light-TUNS-2-32-MVOLT-1-4-GEBHL/202193181/

8ft 4 bulb fixtures. 6 fixtures in 24x24 area. Haven't had any rf problems. Just check the boxes for damage as they can get bent.

Last comment. White gloss paint on ceiling also makes big difference.

 

[jacobsed]

Are those fixtures rated for 0 degrees F?

I found it is more about the bulb than the fixture. I use these bulbs http://t.homedepot.com/p/Philips-4-...66585?storeId=10051&langId=-1&catalogId=10053

It's amazing the difference a bulb makes. I find these are good for garage/work space. Very white and bright.

For the fixture I used http://t.homedepot.com/p/Lithonia-L...ip-Light-TUNS-2-32-MVOLT-1-4-GEBHL/202193181/

8ft 4 bulb fixtures. 6 fixtures in 24x24 area. Haven't had any rf problems. Just check the boxes for damage as they can get bent.

Last comment. White gloss paint on ceiling also makes big difference.

 

[davetulk]

According to the spec on HD "Starts reliably down to -20ºF" I will never have the chance to test that here in Florida I hope.

 

[JoeFin]

JimD1,

My garage 24'x48'=1152 sq-ft

1152x100FC(foot candles)x2(factored efficiency)/2800Lumens/2lights per fixture

Results in 41 fixtures.

David

You dropped a Zero some where

30ea of those fixtures with the cheapo 3200 lumen lamps would put you well over 100 fc

Unless your building a REALLY BIG paint booth you might want to rethink that calculation. Additionally that much infrared shifted fluorescent light WILL FORCE your pupils closed - a fact that can't be changed

Another really great benefit of too much lighting will be all the Heat generated by all those fixtures. Not so bad in the winter but it will probably **** pretty hard in the summer

Here is a pretty easy to use lighting calculator

http://www.visual-3d.com/tools/interior/Default.aspx?id=14783

Try punching in your dimensions and let us know what you come up with.

 

[Ray916MN]

My shop is the exact same area dimensions as the OP's. I used 44 4' 2 tube strip fixtures with 5000K T8 bulbs. Whether the OP is over lighting or under lighting can not be determined from the information provided.

The missing information is the ceiling height, ceiling finish, ceiling color, wall color and floor color and whether the walls are lined with shelves or other stuff that will absorb light.

The OP used a factored efficiency of 2 to compensate for losses to the ceiling, walls, floor and stuff along the walls. I used the same factor when I planned my lighting to account for my 14' ceiling height, the amount of stuff lining my walls and losses to ceiling from using fixtures without reflectors. Any lighting calculator will give you an idea of where to start from, but judgement is required to figure out what will work in the real world.

This is what this level of lighting looks like shortly after it was installed.

With the pallet racking filled and the bulbs burned in, it is not quite as bright today.

No complaints about too much or too little lighting from me. I also host race watching parties on the workshop 60" LCD and get no complaints about the lighting level.

Lastly the 44 fixtures doesn't included the 12 fixtures that are mounted underside of the pallet racking to light the bench tops and overhung area under the racking. The fixtures were the cheapest fixtures available at Menards, about $14 a fixture as I recollect with lower end Sylvania ballasts. No problems with RF interference FWIW.

 

[David C]

JoeFin,

Thank you for your comments. If I dropped a "0" somewhere then my fixture calc would be off by a factor of 10. Up or down depending upon whether the drop was in the numerator or denom'. An order of magnitude error does not intuitively seem likely. If you have time can you look at this again and pin down where you think I might have erred. I did not try your suggested lighting calculation yet.

Ray,

Thank you for your comments and photograph. I was concerned after reading Joe's comments and your post eased my mind; I believe I am not way off with my design.

If you wish to comment; my ceiling height is 9'6", ceiling and wall color will be off-white, and perimeter shelves and benches will definitely reduce reflectance. I will move some shelves from another building and those shelves, including contents, will absorb much more light than your installation. I don't think my garage will be as bright as yours.

My plan is to have several switches on the lighting to allow various lighting levels. However this kind of adjustment allows only discrete level ajustments so I am interested in getting close to a usable installation. It is not my intention to have the shop portion either too bright or too dim.

Forgot who commented on lighting heat gain. While this is an important consideration to most applications it doesn't matter much to me; daytime highs are 65 max in summer and 55 in winter.

D