Lighting calculation

[Desertwndrr]

Is there an online lighting calculator that anybody knows of to help estimate lighting in my new shop? I am in the process of building a 22x60 bay with 16' ceilings. Was thinking that it needed 14 or so 6-bulb T8 fixtures, but as I read around I think that may be a bit much?!? Any help would be appreciated.

 

[tfinniii]

Yes I would like to see a calculator that tells you the number of bulbs due to square footage and ceiling height and not have to get messed up with lumen figuring calculators.

 

[JoeFin]

Most manufactures have them as a means to push you towards their lighting products

This 1 looks to be a little more independent of manufactures

http://archlight.wordpress.com/2007/08/31/awesome-free-lighting-analysis-software/

 

[6768rogues]

I did lighting calculations as part of one of my college courses. It involves the distance from the light to the work, what kind of work is being done and the color/reflectivity of the surfaces. It is not a simple calculation. Also direct lighting is different from indirect lighting.
Down and dirty method: Online you should be able to find examples of how much light (lumens per square foot or similar quantity) for a type of work you are planning. Check the specs of some lights to see how many lumens are produced. Do the math to see how many lights you need for the desired light per square foot. Add a little for high ceilings, if you have them. Add a little for dark or dull surfaces, subtract a little for white, shiny reflective surfaces. Close enough.

 

[Ruger_556]

Install as many lights as you think you need... Then add more!

 

[JoeFin]

This lighting layout calculator is the easiest to use

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

 

[Desertwndrr]

Thanks all. Joe, that calculator is exactly what I was looking for.

 

[2ManyProjects]

Is there an online lighting calculator that anybody knows of to help estimate lighting in my new shop? I am in the process of building a 22x60 bay with 16' ceilings. Was thinking that it needed 14 or so 6-bulb T8 fixtures, but as I read around I think that may be a bit much?!?

If you're thinking about it purely in terms of "average" brightness, perhaps so (it works out to just shy of 180 source lumens/ft.^2). But the far more serious problem is that all that lighting power is concentrated into far too few sources, spread much too far apart. Even with 16-foot ceilings (and concomitantly presuming that you mount the fixtures at/near ceiling height), it is a pretty good bet that just 14 fixtures is not nearly enough to provide good EVEN illumination of a 1,320 ft.^2 workspace. If you lower the mounting height in order to reduce the losses imposed by the source-subject distance, you only further exacerbate this problem.

Any help would be appreciated.

You need to look at a photometrics chart for whatever fixtures you're (seriously) considering, and find the angle at which their output falls off more than about 30-40% (50% TOPS; but that's really pushing your luck). Typically, this will be no more than about 45 degrees (possibly less) for a so-called "High Bay" fixture. This, after a bit of applied geometry (and/or the "Spacing Criterion", if specified), will tell you how far apart the fixtures can be spaced, vis-a-vis their mounting height, and still provide "adequately" even coverage down at working height.

 

[MN4x4]

I tried both calculators and they each have their strengths. The visual tools is quick and easy, but very basic. I really like the DiaLUX one. With only a couple of hours of playing I was able to come up with this design for my shop, which has a funny vaulted ceiling:



I am quite impressed!

 

[JoeFin]

I really like the DiaLUX one. With only a couple of hours of playing I was able to come up with this design for my shop, which has a funny vaulted ceiling:



I am quite impressed!

Very impressive

The Dialux program went into detailed calculations on reflectivity and was able to choose any manufacturer you wanted

 

[dtcooper]

Hey guys, I'm the new guy here... I'm in East Texas.. I'm a manufacturer's rep for one of the big 4 Lighting manufacturers.. Been doing it about 22 years !
Someone above touched on it, and I"ll expound just a little bit..
Think of your room as a bucket.. To achieve a certain level of light at workplane height, you'll require a certain number of lumens. Just like drops of water, to fill a bucket. If your fixture puts out 200 drops, and you need 800 drops total, you'll use 4 fixtures..

Now, ceiling, wall, floor reflectance, all have a bearing on the true usable lumen levels (at workplane height).
The best and most thorough way to do a true lighting layout, is using the IES files of which ever fixture you're considering.. The file contains all photometrics of each particular fixture. A 3D rendering can be done and it will be actual and true..
While some of the online calculators are decent at "getting by", a more in depth, fixture specific program is better.
I get paid good money to do lighting layout and design for my company.. But if I can be of service or help to you guys here on the forum, on basic layout and design, don't hesitate to ask..

 

[humblejohn]

Hi dt...Just joined the Garage and will take you up on your offer! Doing a 2 car garage for hot rod projects. 24 ft wide by 30 x 8. 2 garage doors on the 24 side and 2 ft. of cabinets and stuff on the 3 remaining sides. Thinking of doing LED's if not way extra expensive. Want lots of light in each of the two car bays......probably one switch to control both......will keep limited lighting for other getting around like doing laundry. Please give me some directions. Thank You! John

 

[atfulldraw]

Hey guys, I'm the new guy here... I'm in East Texas.. I'm a manufacturer's rep for one of the big 4 Lighting manufacturers.. Been doing it about 22 years !
Someone above touched on it, and I"ll expound just a little bit..
Think of your room as a bucket.. To achieve a certain level of light at workplane height, you'll require a certain number of lumens. Just like drops of water, to fill a bucket. If your fixture puts out 200 drops, and you need 800 drops total, you'll use 4 fixtures..

Now, ceiling, wall, floor reflectance, all have a bearing on the true usable lumen levels (at workplane height).
The best and most thorough way to do a true lighting layout, is using the IES files of which ever fixture you're considering.. The file contains all photometrics of each particular fixture. A 3D rendering can be done and it will be actual and true..
While some of the online calculators are decent at "getting by", a more in depth, fixture specific program is better.
I get paid good money to do lighting layout and design for my company.. But if I can be of service or help to you guys here on the forum, on basic layout and design, don't hesitate to ask..

If you have time, I'd like to see what a lighting layout would look like on my 40x60x15 barn/shop with a 2/12 pitch on the roof.

I'm in the hill country, but originally from Longview

 

[manya]

Install as many lights as you think you need... Then add more!
It involves the distance from the light to the work, what kind of work is being done and the color/reflectivity of the surfaces. It is not a simple calculation. Also direct lighting is different from indirect lighting.