Unreasonably low DF values

Hi everyone,
I am having a problem with my GH/HB definition for DF calculation, which is that DF values are too lower than what is expected:

I tried troubleshooting by changing window transmissivity and checking the direction of all the surfaces but it did not work,
I attached the file,

Thanks in advance for trying to solve this issue,


image

DF.gh (82.4 KB)