Brewery lighting calculations


Senior Member
You can twist it any way you want, but according to the general statement, no general illumination can be calculated under 220.14. What receptacle outlets are included with 220.12 has no bearing on that. I still say you must use 220.12 and its table for general illumination.
I'm not twisting anything. You are just misinterperting what is meant by general illumination.

General illumination simply means we don't really know what the connected wattage will be.
It only applies to the occupancies listed in 220.12. The term general means that some part of the lighting load can be reasonably expected to be floor lamps, table lamps, desk lamps, display lighting, task lighting, or similar plug in fixtures. It's general lighting because it can be moved, added, or removed without an electrician and without a permit. It's general lighting because there is no way to know the actual connected load, therefore we have to use watts per square feet.

in contrast, consider a car wash. Everything is permenantly installed watertight fixtures. There is no movable plug-in general illumination. Therefore, 220.12 doesn't apply, and we simply use 220.14 to figure the connected load.

it seems painfully obvious to me that the short list in table 220.12 wasn't intended to apply to every type of building or occupancy imaginable.


Senior Member
West Chester, PA
Perhaps.... but I don't think so. Anyone else care to weigh in on this?
You can get some pretty good footcandle levels nowadays with 2W/ft². If your design service capacity complies with 220.12, you will always have enough power to meet the watt densities of ASHRAE or IECC.

I used to design lights for footcandle levels first. Now the first thing I do is see how many lights the energy code lets me use. Then I'll look at the footcandles to see if it's too much (is there such a thing as "too much"?)