Hello,

I tried to compare the three softwares ecotect, radiance (by exporting-reimporting with ecotect), and dial europe. I modelled a simple box: 3m by 3m by 3m. With one window in the middle of the southern façade. With the same material properties. Reflectances: .3 for the floor, .7 for the wall (I know, it's a bit high..) and .8 for the ceiling. The window measures 1mx1m and has a transparency of .6375 (the glass has a TL=75 and 85% of the window is glazed, hence the total TL is 0.75*.85=0.6375). I am attaching my model.
With radiance, I tried with 2,4 and 6 reflections. The results I got are in the excel file I am attaching. Basically, the radiance results are way below the other two softwares, especially with 4 reflections. Ecotect and Dial Europe don't get exactly the same results, but they're pretty close...
I don't know what to think of this, when everybody seems to agree that radiance gives the most precise results, and even more precise when you increase the number of reflections!
Which one should I chose, does anyone have an idea?

Any help would be greatly appreciated!

Alice