I was thinking that this morning! I know there isn't a ton of moisture from that pack I put in but that isn't the same as the ventilation. I only have two vents the first is the one at the bottom of the coop shown in my first photo this is the second.
It's near the top but I think the wire is too large so I'll put another layer of wire there. The holes near the bottom are for little wooden slide doors to collect eggs. They need repairing. I don't want to make it too drafty but dont know if those two vents will keep the coop free of gasses. The way it's looking I might have just three hens now. They're getting older and some look like they might be roos.
I worry a lot! I want to make sure that the are not cramped, that their area is secure and that they are happy and healthy. I don't want to cause any deaths or illness due to my inexperience. But I really enjoy having and caring for my little ones. You've taught me a ton so I am very grateful!
For 3 hens that ventilation seems adequate. The sliding drawers are a puzzle to me and seem easy access for predator claws to pull open and enter the coop. Put secure locking latches on them so a 'coon can't slide them open.
I don't know what your climate temps are but in the late summer we get 100+ temps and I leave the cleanout nestbox door open for more ventilation but I stay up all night to make sure there are no predators - the coop is 10 steps from the kitchen sliding door. Silly? Maybe. But as I said I'm a worrier. Our newest coop won't have ventilation problems. The best thing is to use a 1/2" hardwire screen door as a people door and use a thin plywood screen door insert cover for night-time or inclement weather days. Just some ideas as I don't know what your final look will be like.
Re-homing roos is heartbreaking. One was sent to us as a pullet and we have to re-home the sweetie!