Adjusting Thresholds for Annual Grid Analysis

Annual daylight simulations calculate metrics based on industry standards for adequate daylighting levels over the course of a year. Specifically, Annual Sunlight Exposure (ASE) is conventionally described as the percentage of calculation points receiving direct sunlight for more than 250 hours per year. Spatial Daylight Autonomy (sDA) and Spatial Daylight Saturation (sDS) report the percentage of a space receiving at least 300 lux for at least 50% of occupied hours. Daylight Autonomy (DA) and Continuous Daylight Autonomy (cDA) report the percentage of occupied hours exceeding the standard 300 lux threshold. And Useful Daylight Illuminance (UDI) reports the percentage of occupied hours with illuminance levels between 100 and 3000 lux.

These default values are determined using industry standards and best practices, based on practicalities of lighting typical spaces for typical operation conditions. However, for more specialized applications it can be valuable to adjust these ranges and targets to suit the specific design goals of the project.

Before starting an annual grid analysis, all threshold values can be set in the settings dialog. First, enable the metrics of intertest for the simulation. The applicable fields will then appear in the thresholds section to set before starting the simulation.

1. Enable metrics of interest.

   
   

   

   
   

2. Expand the Thresholds section to set appropriate values.

   
   

   

   
   

3. Start the Annual Grid Analysis.