Asymmetry in Daylight Factor Results and modification of UDI

Hello all,

I am new to Radiance / Daysim, so I hope you can help help out with a few questions.

I am using DAYSIM via Ecotect to simulate the daylight conditions for an office, 4 x 5 m, symmetrical geometry, with one window. I noticed that the Daylight Factor results were not completely symmetrical. Deviations are typically around 0.1-0.3 % DF. I tried increasing the number of ambient bounces from 6-8-10 which did not eliminate the asymmetry. I contacted an engineer who has been using Daysim via Ecotect in his ph.d. study, and he wrote that his Daylight Factors were also a bit asymmetrical. Can anyone explain why this is the case? In theory the Daylight Factor should be completely symmetrical, as the CIE Standard Sky is symmetrical. Does this have anything to do with Daysim using the Daylight Coefficient Method?

Another thing is that I would like to modify the UDI to make it case dependent. So instead of using 2000 as the upper limit for useful daylight, I would like to insert a sensor point, calculate the DGP (Daylight Glare Probability), and use this as the upper limit. Does anyone know if it is possible to extract the results for each hour, for each sensor point, to count the hours of useful daylight based on this?

Thank you in advance,
Amalie Momme