Coefficients of Utilization

A method is presented for the direct determination of Coefficients of Utilization applying to installations of all ordinary types of lighting units in rooms of varied proportions and different ceiling and wall colors. As a basis for the method, Coefficient of Utilization data are tabulated from a series of several hundred illumination tests made in an experimental room with reflectors having three fundamental forms of light distribution. Illustrating the application of the data presented, typical Coefficient of Utilization Tables, as determined for a number of reflector types in common use, are included.