A number relating the dimensions of an enclosed space ( length, width, height) that effects the overall coefficient of Utilization of a luminaire within that specific space. The actual values used in the calculations were: 1 for RCR A, 5 for RCR B, and 7 for RCR C
Room Cavity Ratio. A shape factor (for a room, etc.) used in lighting calculations. RCR = 5H (L+W) / L x W, or, alternately, RCR = (2.5) Total Wall Area / Floor Area. Where H = height, L = length and W = width of the room. A cubical room will have an RCR of 10; the flatter the room the lower the RCR.
Room Cavity Ration. A number indicating room cavity proportions calculated from length, width and height.