How many lumens per square foot???

[bobmulry]

Hi,

I posted this in the Hot Deals section thread that was talking about LED lighting but I received no responses..........so I guess that I will repost it in the correct section

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Hi All,

I am just getting started on collecting estimates to build a 40' x 60' shop / garage.

I would like to find out how many lumens per square foot of floor space are needed to have a "well lit shop" and what is the most economical type of lighting??????

Thanx,
Bob

 

[pattenp]

My opinion is at least 100LU per sqft and T8 fluorescent fixtures.

 

[Highbeam]

I am very happy with my 62 LU/SF at a 14' ceiling height with t8s.

Any more light than that would be task lighting.

 

[Tronyadorable]

I'm at 80 pf. Plenty bright. Too bright at night.
Four 175 cfl's

 

[pattenp]

Here's a good reference....
http://www.engineeringtoolbox.com/light-level-rooms-d_708.html

 

[Ray916MN]

I'm in the 200 lumens per square foot camp.

The thing that is particularly important to consider when you look at the lumens output of a light is it lights not only the floor, but also the walls and ceiling. This is particularly true in the absence of a reflector on the fixture. This means a 100 lumen bulb in a 1 foot cube appears to hit 100 lumens per square foot, but since the interior surface area of the cube is 6 square feet, it only hits ~17 lumens per square foot in terms of direct lighting. The reflectivity of the walls, ceiling and floor and the concentration of the lighting needs to be factored in and considered to hit a given lighting level.

So when I say 200 lumens per square foot, what I mean is I want the output of the lighting of the bare bulbs on the ceiling to put out 200 lumens per square foot of floor space in the hopes that I'll actually hit something closer to 100 lumens per square foot after losses to the ceilings and walls are considered.

If I were lighting with fixtures with reflectors (or if the ceiling and walls were mirrored) which minimized the amount of light hitting the ceiling and walls , I would aim for 100 lumens per square foot.

Then again I'm middle aged with poor eyesight working on motorcycles with lots of small fasteners...

 

[pattenp]

Obviously it's all a personal perspective. I have a garage that has 13' ceiling with 123LU per sqft and a shop with 8' ceiling with 87LU per sqft. To me the shop appears brighter than the garage but that has to do with the lower ceiling. i can't say my 123LU per/sqft is like task lighting.

 

[Ch3No2]

I used 4 tube double ballast fixtures so I could have 2 tubes on or 4 tubes with switch control of each fixture...4 tubes on is about 180 and 2 is of course 90...decent light at 90 but pure daylight at 180...white walls and ceiling sure help

 

[bobmulry]

Thanx for the info...........

That helps me make a discussion on lighting.....

Bob

 

[CNGsaves]

With proper wiring and switches, you can control how much light you have going. Setup the shop in sections so if you rarely go to back, have that portion of shop on separate switch. Also, wire just half of light bulbs in a fixtures on a switch, then you can turn on half at a time. Flip 2 switches and all bulbs of the fixtures light up.

Be creative and decide what YOU might want, based on how you'll use the space.

 

[Ch3No2]

With proper wiring and switches, you can control how much light you have going. Setup the shop in sections so if you rarely go to back, have that portion of shop on separate switch. Also, wire just half of light bulbs in a fixtures on a switch, then you can turn on half at a time. Flip 2 switches and all bulbs of the fixtures light up.

Be creative and decide what YOU might want, based on how you'll use the space.

Exactly, I have 4 switches for the area in the picture...I can have 20, 40, 50 or 60 tubes on at discretion...but you will need double ballast fixtures

 

[bzinsky]

With proper wiring and switches, you can control how much light you have going. Setup the shop in sections so if you rarely go to back, have that portion of shop on separate switch. Also, wire just half of light bulbs in a fixtures on a switch, then you can turn on half at a time. Flip 2 switches and all bulbs of the fixtures light up.

Be creative and decide what YOU might want, based on how you'll use the space.

this, I have 6 light switches in my 2 car garage, and 4 in my little basement shop, previous owner did it, I love it.

and t8's are by far the most cost effective way to get the lumen output you want, and LED comparable efficiency.

Oh and when you have that much energy by lighting, I highly suggest one of those motion sensor light switches.

I haven't put them in yet, but I have one in my office, I love it. I don't use the motion on part, I just push it on. When I turn the light on, it turns off in 30 minutes if it doesn't detect motion. I don't even know it's there until I forget to turn my lights off and I come back in and it's off.

My garage has 4 double t8 fixtures that turn on when I just want to use the garage to grab something like the lawnmower. 2 switches for 2 outside lights. 1 switch controls 8 more t8 fixtures for when you are working in the garage. So that's 12 total, and then there are two workbenchs, each with (4) t8 fixtures, for when I need to use the bench, which both are currently covered with ****. Either way, you can never have too much light. What my ultimate goal is to cut out thin strips in the slab and recess some led strips. I would love for the floor to light up so I can work on my car. Not sure how that's going to work though without having to be a pain in the ***, I mean you can't rest the leg of a jack stand on an LED strip.

We're currently is process moving our offices into former eckerd drug store that was built 10 years ago. It seems like every 5 feet there's a quad t8 fixture with a mirror finished housing.

I'd take a close guess and say there are about 400 t8 bulbs in there lighting up about 9k sq ft, that's about 133 lumens per sq ft. As you know, newer drug stores/supermarkets are quite bright inside. There's no shortage of lighting. I can't imagine needing anything more than that. Then again, they usually do have bright colored vinyl tile, I'm sure that has a big impact on the lighting.

 

[bzinsky]

I used 4 tube double ballast fixtures so I could have 2 tubes on or 4 tubes with switch control of each fixture...4 tubes on is about 180 and 2 is of course 90...decent light at 90 but pure daylight at 180...white walls and ceiling sure help

that looks pretty much identical to the drug store I am talking about. That's a nice looking setup. I bet the finished walls help a lot reflecting the light.

 

[bzinsky]

Lol, tt's amazing how 3 60watt bulbs can light the hell out of one's living room. Go into a shop or basement of seemingly the same size with the same bulbs, and you can't see squat.

 

[Autorotica]

Wow... You guys must be performing brain surgery in your sheds.

This is just under 30 lumens per foot... 30 Costco 3700 lumen LED lights in 3840 square feet. Went with these because the space is unheated and I was concerned with keeping running costs down. Works out to $0.16 per hour to have them ALL on.



Chris

 

[W_A_Watson_II]

I targeted 100 at the floor, and when the T-12's were new the light level was great. Now that the Fluorescent Tubes are 8 years old (and my eyes are older as well), the light level is no longer adequate. It's time to re-tube the shop, 96 tubes covering a 52x46 area.

 

[stage20]

placement of those lumens is the key. you can have 10,000 per foot but if they are all on one side of the shop, you will have shadows and dark spots. im right at 100 lumens in my shop. 12ft up t8 lights. i have them mounted to close together for changing brakes at night, but it is insanely bright for everything else. im going to add more fixtures further out in the future.

with my door up, half my backyard is lit up at night. 120ft to the road and its still bright.

 

[Ch3No2]

Wow... You guys must be performing brain surgery in your sheds.

Chris

Sometimes it is.....

 

[pattenp]

Wow... You guys must be performing brain surgery in your sheds.

This is just under 30 lumens per foot... 30 Costco 3700 lumen LED lights in 3840 square feet. Went with these because the space is unheated and I was concerned with keeping running costs down. Works out to $0.16 per hour to have them ALL on.

Chris

In this case a picture is not worth a thousand words because the exposure can make the lighting look darker or brighter than it is to the eye. 30 LU per SQFT is good for office work levels.

 

[Kevin C]

It depends on how you calculate your lighting. Some just take the total lumens from the tubes and divide it by the area of the shop. Since fixtures vary from 60 to 85% in efficiency at taking what comes out from the tube to what makes it to the work surface, it obvious what you get at the work surface is a lot lower.

Using that method I probably have 120 lumens per sq foot. At bench height I get a delivered Lumens of about 70. On the floor... figure fifty or so ( this is from memory).

That said, its pretty bright in my shop and I have no problem working on projects.

LED fixtures are rated for actual output.

 

[Ray916MN]

Wow... You guys must be performing brain surgery in your sheds.

This is just under 30 lumens per foot... 30 Costco 3700 lumen LED lights in 3840 square feet. Went with these because the space is unheated and I was concerned with keeping running costs down. Works out to $0.16 per hour to have them ALL on.



Chris

Looks good and is perfect example of how reflectors can really help make lighting more effective. Notice how the ceilings and the walls are not strongly lit. The reflectors place the light on the floors, not on the ceiling and walls.

Here is what 200 lumens from strips looks like

Notice also that there is pallet racking and art high on the walls so strips were used to make sure the walls and ceiling were lit and light gets into the pallet racking.

Notice that the lighting level pictured should look dramatically different (30 vs. 200 lumens), but does't look very different as this is very true.

In this case a picture is not worth a thousand words because the exposure can make the lighting look darker or brighter than it is to the eye. 30 LU per SQFT is good for office work levels.

Finally, while the ceiling of my workshop is 13.5' high, I suspect Autorotica's ceilings are closer to 18'. Anything over 15' is where reflector high bay fixtures should be considered to ensure that lighting is effectively focused at the working level.

Net is designed lumens per square foot is very different than effective lumens per square foot and building size, use and where you want light all need to be considered to come up with effective lighting. Simply calculating lumens per square foot and thinking all you have to do is to lay it out correctly after you have figured out what fixtures/bulbs will give the lumens per square foot you want may not be effective at getting you good lighting.

 

[whitemamba]

Wow... You guys must be performing brain surgery in your sheds.

This is just under 30 lumens per foot... 30 Costco 3700 lumen LED lights in 3840 square feet. Went with these because the space is unheated and I was concerned with keeping running costs down. Works out to $0.16 per hour to have them ALL on.



Chris

what is you shop size, eave height, and pitch? I am really thinking about the costco lights for my new shop! Did you hang those all at same height from floor to light?

 

[Autorotica]

Sometimes it is.....

Well that bumpystick makes the 55 and 60mm bearing small block stuff I used to play with look like something one would find in a Briggs and Strat!

Thanks for the pic!
Chris

 

[Autorotica]

what is you shop size, eave height, and pitch? I am really thinking about the costco lights for my new shop! Did you hang those all at same height from floor to light?

Shed is 60 x 64. Eave height is 16' I think the pitch is 4/12. Scissors truss lower chord raises about 3' from the eave to the peak.

The majority of the lights are at roughly 14'. Along the south wall they are lower because of the clearview panels. Having them at 14' had a sizeable amount of light shining thru the panels to the outside. A few lights were slid over, lowered and/or raised as to what seemed sensible around the 14' garage doors and hardware too.

A friend has a foot candle meter and I just recently asked him to stop by and take some measurements. I would be happy to share our findings once this transpires.

Hope this helps...
Chris

 

[whitemamba]

Shed is 60 x 64. Eave height is 16' I think the pitch is 4/12. Scissors truss lower chord raises about 3' from the eave to the peak.

The majority of the lights are at roughly 14'. Along the south wall they are lower because of the clearview panels. Having them at 14' had a sizeable amount of light shining thru the panels to the outside. A few lights were slid over, lowered and/or raised as to what seemed sensible around the 14' garage doors and hardware too.

A friend has a foot candle meter and I just recently asked him to stop by and take some measurements. I would be happy to share our findings once this transpires.

Hope this helps...
Chris

awesome, i am doing 40x60 with 16' eave 3'12 pitch, is the one side with the clearview worth it for daytime light?

 

[Autorotica]

awesome, i am doing 40x60 with 16' eave 3'12 pitch, is the one side with the clearview worth it for daytime light?

Absolutely!

I posted a pic inside the shed with the doors shut in another thread. See if this linky works.

http://www.garagejournal.com/forum/showthread.php?t=252055&highlight=autorotica

If not, its in the general discussion forum and the title of the thread is "Translucent panels in the walls or roof of a shop?"

Chris

 

[Highbeam]

I am very happy with my 62 LU/SF at a 14' ceiling height with t8s.

Any more light than that would be task lighting.

I was not very clear and gave pattenp the wrong impression. I am very happy with the 62 and if I need it brighter to do a specific job then I deploy task lighting at much higher levels. This is not to say that I think anything higher than 62 is task lighting. I believe in two light levels, one being the necessary general light for safety and sufficient light for most tasks. The other light level is what is needed for detailed tasks like rebuilding a carburetor or even waxing an auto.

I recently finished my white metal ceiling and while it does seem to make more light hit the ground, a bit brighter, it is not like night and day compared to just the t8 strips on the trusses.

 

[Rickss96]

Ch3No2 - what kind of motor is that???

 

[synik]

Wow... You guys must be performing brain surgery in your sheds.

This is just under 30 lumens per foot... 30 Costco 3700 lumen LED lights in 3840 square feet. Went with these because the space is unheated and I was concerned with keeping running costs down. Works out to $0.16 per hour to have them ALL on.

Chris

Hey Chris, can you tell me what brand / model number are these lights? I can't see to find it online. Instore? Cost?

Thank you! Looks great!

 

[Falcon67]

Wow... You guys must be performing brain surgery in your sheds.

Sometimes it is.....

Brains...brains...brains...

 

[W_A_Watson_II]

Whatever you decide on... Double it.
However many circuits you decide on... Double it.

 

[Autorotica]

Hey Chris, can you tell me what brand / model number are these lights? I can't see to find it online. Instore? Cost?

Thank you! Looks great!

Synik,

Unfortunately they are not listed online. You can find all the information you are inquiring about on this thread... http://www.garagejournal.com/forum/showthread.php?t=270879

Thank you!
Chris