Estimates by the zonal-cavity method (IESNA average-illuminance procedure). The coefficient of utilization is estimated from Room Cavity Ratio and surface reflectances for a generic direct distribution — for a stamped design, enter the CU from the fixture's photometric report. The point-by-point heatmap is a modeled estimate (direct cosine component normalized to the zonal average) and is not a substitute for a calculation from the luminaire's IES file.