I added these Solar exhaust fan to two chicken coops and a duck coop this summer during our extended heat waves. They were much bigger than I thought they would be and move a lot of air. I also liked that it came with the power plug to run during the night as well which they usually don't come with. I added hardware cloth across the vent for predator protection and keep the mice out. I had all windows open as well as the human doors but if there is no wind blowing, that didn't help much. I was using box fans previously but those always scare me with the amount of dust the chickens produce and the possibility of fires.