warehouse lighting

I am working on a 80x110 steel warehouse building. Long story short, the original planned use and occupant of the building has been nixed, and the original plans have been thrown out the window. It has basically fallen on me to spec and design the lighting. Just want to get a rough idea of an appropriate lighting level. So the 110 foot dimension is divided into 4 28 foot sections by the posts, so I think I would do lights centered in each of those spaces. I would probably use 30,000 lumen LED high bays. Does three in each "bay" sound reasonable? so 12 lights total. That is half the number of lights that was on the original plans which shows an average of 57 Fc. That just seemed like a lot to me, and the owner doesnt really want to spend the money.
 

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
Really occupancy dictates lighting levels. Building codes will indicate foot candles at a given levels for building occupancy specific. Also depending on use and if public or employees and numbers of employees, OSHA may have input as well as to minimum lighting levels. I know NY must meet several requirements, energy code in C405.3; and 1204.3 indicate a level of 10 foot candle measured at 3ft above floor; and 1008 may have impact for minimum egress passages or path lighting levels. Etc.
So really need to know FC for the fixtures at a given height not strictly lumens of the fixtures, as well as occupancies and egress requirements. AHJ may look at all these aspects strictly enforcing or may just walk in and say looks bright enough. Might be worth the time to reach out to the AHJ and feel out what level of enforcement might be levied on this installation. Might be able to get away with a minimum if occupancy type and final user not determined and may change. Keeping in mind energy code maximum wattage/ft2, found in C405.3.
 

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
If you have the time... take a look at https://www.dialux.com/en-GB/. Its free but powerful. We use it in our office. Find light fixtures you like, download the IES files, and plug them into your design. You can even get a 3D rendering to give you an idea how the lighting might look.

I'm not sponsored or a spokesperson for this program. I just think it helps.
 
If you have the time... take a look at https://www.dialux.com/en-GB/. Its free but powerful. We use it in our office. Find light fixtures you like, download the IES files, and plug them into your design. You can even get a 3D rendering to give you an idea how the lighting might look.

I'm not sponsored or a spokesperson for this program. I just think it helps.
Cool, someone before me used something like that as there is a rendering with a grid of the FC and a calculation of the average.

A quick web search shows a warehouse between 10 and 30 . If I take my lumens with the 12 fixtures and divide by sq footage, I get nearly 42. That seems high, is that too simple a calculation and I need to account for the ceiling height?
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
If all of the lumen output from the fixtures was perfectly evenly distributed over the floor area, then lumen / ft^2 gives you the foot candles.

IMHO this is too simple a calculation because you won't get all of the photons out of the fixtures, not all of those photons will be aimed at the floor, and the output of the fixtures will not be even. But it does give you a sanity check.

If you use software and it reports a number > simple calculation then you know something is wrong with the software or its setup. If your simple calculation gives you a number < the minimum you need then you know you need more fixtures.

-Jon
 

dkidd

Senior Member
Location
here
Occupation
PE
You need to look at energy code for maximum allowable wattage, and required automatic controls.
 
You need to look at energy code for maximum allowable wattage, and required automatic controls.
Yes. There is perhaps a bit of a "gray area" as to exactly what classification this space is. We are calling it a "warehouse" but it may be more of a "workshop" which would be about 4 times the lighting allowance. I dont know exactly what it is called on the building permit or how the AHJ handles the classification for lighting allowances. At he lowest allowance of "warehouse" I could have 13 of those 30kL fxtures, and I was thinking 12 so f I want to play it safe, looks like was right on.
 

LT Sparky

Member
Location
Farwell, TX, United States
Occupation
Estimator Project Manager
Most of the shops we wire are ag related and are usually up to us to design. I use the RAB website for nearly every shop we wire. EZ layout tool. If you dont wanna use a RAB fixture just pick one with the same or close lumen output. You enter the size of the building including the height and either the amount of fixtures or foot candle you want. It even gives you the measurements to mount.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Maybe I missed it, but is this in Washington or New York? I think those states have very different energy code requirements. Your warehouse might be required to do "daylight harvesting" or some such exotic thing, depending.
 
Maybe I missed it, but is this in Washington or New York? I think those states have very different energy code requirements. Your warehouse might be required to do "daylight harvesting" or some such exotic thing, depending.
This is Washington. Yes the energy code is quite complex. Usually the inspectors just enforce the basic stuff like OC sensors and controlled outlets (**fingers crossed**). It's up to elec inspectors to enforce it, there is no third party certification or such.
 
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