ceiling cavity index
quotient of the sum of the areas of the ceiling and the plane of the luminaires and the sum of the area of the walls bounded by the ceiling and the plane of the luminaires, used in the calculation of the utilization factor or utilance
Note 1 to entry: The ceiling cavity index is given by the formula where
Note 2 to entry: See also "floor cavity index" and "room index".
Note 3 to entry: The ceiling cavity index has unit one.
Note 4 to entry: This entry was numbered 17-131 in CIE S 017:2011.