I have a state owned youth detention center (jail) project in lighting zone LZ1. Being a detention facility, dusk to dawn lighting is required around the entire perimeter, even where there is no parking, drive, doors, or other area that falls into the area categories of Reference Guide SSc8 Table 1 or ASHRAE 90.1 Table 9.4.6 for building exterior lighting power allowances. How should this lighting area be classified for LPD?
Additionally, the facility has a large outdoor recreation yard that includes a softball field and an Area Of Refuge, and borders a perimeter fence of the site. How should this lighting area be classified for LPD?
The recreation yard and perimeter fence lighting is provided at a rather high FC level as required by the Owner, but is automatically reduced to 1/2 lighting after hours with the ability for Security Control to override. Can this automatic reduction of FC and thus fixture watts be accounted for in the LPD calculation?
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
731 thumbs up
June 12, 2017 - 12:02 pm
This credit will be a pain for your project.
Regarding perimeter lighting, there is no clear direction. I have two ideas.
1. Use building grounds "Special feature areas" and count a small strip of land along the perimeter. You might get challenged on this. I can't find any definition for "special feature areas". Generally only hardscape is counted for LPD.
2. Or it may be exempted from the LPD. If you use the v4 version of this credit then ASHRAE 90.1-2010 is applicable. In this version, "searchlights" are exempt from the energy consideration. But they are not exempt from spill light or uplight requirements.
Regarding the outdoor recreation yard, the lighting for athletic playing areas is exempt from the LPD. But again, they are not exempt from the spill light or uplight requirements. For the area of refuge, maybe the "special feature area" category could be used.
The full wattage of the lighting must be used. Even if controls allow for reduced light levels. Have to assume worst case.