MODEL LIGHTING ORDINANCE - USER ’ S GUIDE MODEL LIGHTING ORDINANCE -
TEXT
IX . TABLES - TABLE C BUG RATING ( cont .) - User ’ s Guide IX . TABLES ( cont .) - Ordinance Text are based on the internal and external design of the luminaire , its aiming , and the initial luminaire lumens of the specified luminaires . The BUG rating limits also take into consideration the distance the luminaire is installed from the property line in multiples of the mounting height ( See Table C ).
The three components of BUG ratings are based on IES TM-15-07 ( revised ):
Backlight , which creates light trespass onto adjacent sites . The B rating takes into account the amount of light in the BL , BM , BH and BVH zones , which are in the direction of the luminaire OPPOSITE from the area intended to be lighted .
Uplight , which causes artificial sky glow . Lower uplight ( zone UL ) causes the most sky glow and negatively affects professional and academic astronomy . Upper uplight ( UH ) not reflected off a surface is mostly energy waste . The U rating defines the amount of light into the upper hemisphere with greater concern for the light at or near the horizontal angles ( UL ).
Glare , which can be annoying or visually disabling . The G rating takes into account the amount of frontlight in the FH and FVH zones as well as BH and BVH zones .
BUG ratings apply to the Lighting Zone of the property under consideration .
USER ’ S GUIDE - Page 27 ORDINANCE TEXT - Page 27
Appendix B : Model Lighting Ordianance Page B-27