duct fan

Wondering if anyone has any ideas this is a drawing i came up with to vent my 2 hoods have sealed room grow room not long enough to run end to end cane up with this idea. Dual 6 in fans pulling off 8 in line and ducting out as drawn went with this so ducting isnt in door way any other ideas...

Hey guys I'm trying to keep costs down until I gain more growing experience. So I was considering Duct fan + de-odorizing gel instead of inline fan + carbon filter. Do you all think that would be sufficient? I have a 4 northern lights in a 4x4 tent and from what I hear they are supposed to...