LEED - Lighting requirement

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anbm

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There is an item from LEED for lighting requirement indicates:

"The project lighting is designed so that the angle of maximum candela from each interior luminaire intersects opaque interior surfaces and does not exit through windows."

Does anyone know how we comply with this? I think LEED project is a pain!
Thanks!
 
anbm said:
There is an item from LEED for lighting requirement indicates:

"The project lighting is designed so that the angle of maximum candela from each interior luminaire intersects opaque interior surfaces and does not exit through windows."

Does anyone know how we comply with this? I think LEED project is a pain!
Thanks!
Click to expand...

There is an exception to this requirement. If the lighting is controlled so the lights are off during building unoccupied times (occupancy sensors, time clocks or building management systems) you don't need to comply.

I haven't figured out how you are supposed to comply with this requirement myself!
 
You can also try using a section view. Put the light fixture in place and draw out the lighting angle from the photometric data. Show that it doesn't intersect with the glazing.
 
It is a silly credit. It's indended to prevent light pollution but I think total lumens should be more important than peak lumens.

If the lights in the building are going to be on all night then you'll need to look at the photometric file for the light fixtures. Quite often it's shown on the last page of the light fixture cutsheet. Like this.
http://webconfigurator.cooperlighti...ended_Iridium_Perf_1T5_20090306082633_350.pdf
At the top of the second page it shows a bunch of lighting data. At the top left corner there's a graph showing light intensity at what angle. You can get a rough estimate of what angle has the strongest light output. If you don't like that then look at the top right corner of that page at the table called "Candela". The highest value in that table is 1146. This corresponds to angle 125 degrees perpendicular to the fixture. (0 degrees is straight down)

Look at the interior elevation of this room where the light is installed and draw where this light would be. Is it in the ceiling, suspended, by how much? Now extend a line from the light at 125 degrees to represent the angle of peak light output. If the line hits glass first then you have a problem. If it hits floor, ceiling or wall then you're good. Now repeat for each location and fixture type. Save your sanity and just focus on light fixtures most likely to shine light out of a window.

(It really is easier just saying there's occupancy sensors and calling it a day)
 
ron said:
You perform a point to point lighting calculation (using software and simulating windows, etc) and show that no light would go out the window.
Click to expand...

Engineer83 said:
You can also try using a section view. Put the light fixture in place and draw out the lighting angle from the photometric data. Show that it doesn't intersect with the glazing.
Click to expand...

These are both great ideas ... but from a lighting design standpoint it puts the interior walls in "the dark" which makes the room feel dark.

ASHRAE 90.1 (which is a LEED requirement) requires automatic lighting control. So the requirements of ASHRAE satisfy the exception of this rule.

This is all assuming we're talking about a commercial building application. I know nothing of LEED for residential!
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My question is whether this requirement is in the new LEED 2009 documents since it seems like you don't need to follow it based on the automatic lighting control requirement?
 
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