ceiling cavity ratio
quotient of five times the sum of the area of the walls bounded by the ceiling and the plane of the luminaires and the sum of the areas of 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 ratio is given by the formula where
Note 2 to entry: See also "floor cavity ratio" and "room cavity ratio".
Note 3 to entry: The ceiling cavity ratio has unit one.
Note 4 to entry: This entry was numbered 17-132 in CIE S 017:2011.