This option performs climate based daylight modelling (CBDM) simulations to analyse sDA (Spatial Daylight Autonomy). sDA is the percentage area of the analysed space that is above a certain lux level (e.g. 300 lux) for a certain percentage of the time (e.g. 50% of the time) or more during occupied hours (e.g. 8:00 am to 6:00 pm). It is a metric describing annual sufficiency of daylight levels in an interior environment. The duration/effective times chosen need to be aligned to the requirements.
For example, sDA300,50% would be the resultant sDA for an analysis with an illuminance threshold of 300 lux on the chosen horizontal surface that is exceeded for more than 50% of the annual occupied hours.
Full details of the sDA method can be seen in the Illuminating Engineering Society guide LM-83, Approved Method: IES Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE).
In order to simulate the effectiveness of dynamic blinds a series of independent simulations are performed for each “Window Group” (glazed façade): No blind and With blind using the selected Sky Model.
Preferred and minimal acceptable sDA values are dependent on regulatory guidelines and bodies. This simulation could be used, for example, for LEED IEQ-Daylight (Option 1), as this metric follows the guidance of the Illuminating Engineering Society guide LM-83, Approved Method: IES Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE).
