I have to set the sky to calculate the Glare.
I want to set the sky as a clear, cloudless day, so I want to use “Generate Standard CIE Sky” rather than “Generate Climate Based Sky.”
However, when I measure the horizontal illumination with “Generate Standard CIE Sky” without clouds, the value is significantly lower than “Generate Climate Based Sky”.
Shouldn’t the value be higher when set to Sunny Day than when set to “Generate Climate Based Sky”?
Those two sky types are not related. It is possible that the values of direct normal and diffuse horizontal radiation used (i.e. derived from the TMY data) to create the climate-based sky (ie. Perez Sky Model) are a lot higher than the radiation values generated through the CIE-sky.
Even practically, it is possible that the measured horizontal illumination on really bright but cloudy day is higher than a clear day.
