Oh, my bad, I thought the one with the monitor was the small one! I just didn't see them side by side. On another note, are the roosts in the bigger coop right on top of the nest boxes? If so, you may want to cover the nests, as they will poop straight into them.If anything, the smaller coop has less airflow/ventilation. In fact, I'm thinking about putting more holes in. The larger coop has a monitor-style roof, so the ventilation is open along the entire length of the roof.
Anyway, I was successful in moving a few of the chickens that were looking for a box in the smaller coop into the larger one and shut them in. As you suggested, they were not happy. I moved one of the 3-gallon waterers into the coop and turned a sprinkler on it to keep it and them cool. I also removed the boxes from the smaller coop.
I'm waiting now to see what happens!