I don't have any ideas on how to add ventilation, unless you put something in your door. I just want to say that I love your coop!
Wouldn't the amount of square feet of vent per fowl maybe have something to do with the type of coop you have? It seems to me that the smaller the coop, the more ventilation one would need. I could be way off base here. I'm just trying to learn. My coops have vented soffits, and the windows tip in from the top so I can have them open most of the time without issues. (I have closed them this week.)
Wouldn't the amount of square feet of vent per fowl maybe have something to do with the type of coop you have? It seems to me that the smaller the coop, the more ventilation one would need. I could be way off base here. I'm just trying to learn. My coops have vented soffits, and the windows tip in from the top so I can have them open most of the time without issues. (I have closed them this week.)