Hello,
As of LEED v4 Indoor lighting pollution is a part of Minimum Energy performance credit.
Although this credit should include only external lighting sources, what about an example where warehouse that has
roof skylights ?
This would naturally cause lighting pollution towards zenith / night sky from
the inside of warehouse which is of course a huge source of lighting pollution ...does that mean that warehouse with skylight can not fulfill the requirements of this credit?
Thank you for replies and suggestions in advance,
Anna
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
731 thumbs up
January 16, 2019 - 10:10 am
I'm curious about your statement, "the inside of warehouse which is of course a huge source of lighting pollution"
Skylights are going to become more common since they are part of the energy code for rooms over 15' tall. But I don't see them as much of a source of light pollution now, and doubt they will be much in the future. The largest sources of light pollution are transportation, industrial, and advertising. I'd be surprised if skylights accounted for 0.01% of total light pollution.
My own experience, the lighting in warehouses is 80%-100% downlight. Code LPD is less than 0.60 W/sf. The light is focused on the floor and shelves. And these surfaces are not very reflective. There is not much direct or indirect light going up. The skylights are relatively small, fitting between the joists, they are about 4'x4' or 5'x5'. Total area of the roof is about 4% with skylights. The skylight itself is frosted for diffuse light inside, but that blocks 20% of light from passing thru. And the lights are constantly turning on and off from occupancy sensors picking up the forklifts moving down the aisles.
Can I see a large warehouse with skylights causing noticeable light pollution? Yes. But this will pale in comparison to the light pollution from the adjacent parking lot and loading dock. This credit only measures direct light pollution from exterior lighting. For simplicity, it ignores the indirect light from the pavement. And this indirect light from parking is much greater than anything coming out of a skylight.
This credit for v4 ignores interior lighting. Documenting compliance for interior lighting in previous versions was difficult, time consuming, and for relatively little benefit.
Any warehouse project with skylights is free to attempt this credit, by complying with the exterior requirements. And any project is always able to go beyond the credit if they want. But this credit is not available for an exemplary performance extra point.