can a coon reach the windows? because if they can't then you don't need to be so paranoid about their ability to get through them. i'm with pat, plan to make the windows predator proof and leave them open.
to give you some kind of reference point, our coop is 43 sq ft on the inside for 3 standards. i have 2 4x4" vents and a large opening in the floor (30x160cm) for the ramp which stays open 24x7 providing air flow to the inside (no predator problem here). i knew i was pushing my luck a bit with the ventilation but design constraints made it difficult to provide more easily. it has a bathroom ventilation fan which provides air flow between the vents at each end and i'm currently having to run it 24x7 to keep the smell of ammonia down, and i'm going to have to retro-fit some more ventilation somehow.
to give you some kind of reference point, our coop is 43 sq ft on the inside for 3 standards. i have 2 4x4" vents and a large opening in the floor (30x160cm) for the ramp which stays open 24x7 providing air flow to the inside (no predator problem here). i knew i was pushing my luck a bit with the ventilation but design constraints made it difficult to provide more easily. it has a bathroom ventilation fan which provides air flow between the vents at each end and i'm currently having to run it 24x7 to keep the smell of ammonia down, and i'm going to have to retro-fit some more ventilation somehow.