The Visual Interior Tool is designed to perform lumen method calculations on a rectangular room. The lumen method determines average illuminance achieved on the workplane using a derived property of luminaire photometrics and room geometry called the coefficient of utilization. The lumen method operates under the following assumptions

• Luminaires are spaced uniformly
• Incident flux on each surface is uniformly distributed over the surface
• Room is empty
• Surfaces are diffuse
• Surfaces have neutral color

Because the lumen method provides an average illuminance, point values for calculations might vary considerably. Please use the professional addition of Visual for full lighting analysis.

Values calculated during the zonal cavity method are shown in the collapsible panel below the Display settings. These values are provided to help those curious about how the zonal cavity method works see the intermediary values that must be calculated in order to perform the calculation. For more information on the lumen method / zonal cavity method consult the IESNA Lighting Handbook.

If you have any questions not answered by the tutorial video, or comments on the Interior Tool email VisualSupport@AcuityBrands.com.