I just put this in another thread... you don't want drafts, but you do want vents to allow fresh air in. Just like the vents you have in an attic, exactly. We have an 8x8' coop, with an 8' ceiling sloped back to a 5' ceiling above the nest boxes. At the top of the 8' side we have round aluminum louvered vents at opposite sides to allow airflow away from the birds. They can't get up that high, and the louvers baffle any wind that might be blowing from outside. Without those vents, moisture and ammonia will build up in there so quick, it will make your head spin!
