Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
DesignBuilder v4.7 daylighting calculations don't take into account the illuminance/irradiance data in the epw file. By default for the overcast sky options the sky illuminance is taken as 10,000 lux. I'm not sure about the illuminance used in the sunny sky options, but they are standard CIE sky distributions.
In v5.2 there are options to define the sky illuminance distribution using either the CIE skies (the only options in v4.7) or a set of "Perez all weather" options:
With options 2 and 3 it is straightforward to copy values from the weather file to define the sky illuminance.
