I live in central Nebraska and I'm converting a 5 x 8 playhouse into a coop for my 7 fast growing girls. My son is helping me build a cupola for ventilation. Is a cupola enough or do I need vents in the eaves also?
Actually a cupola can be great to get rid of bad air. Ammonia is lighter than air and will rise to the top. Warm air is lighter than cool air so it will rise to the top too. In the wintertime a cupola may be plenty to get rid of bad air. Part of that is how it is built, how many and what size the openings are. The more vertical difference in the openings the more air exchange you can get. Other openings above where they roost is a good idea in winter, but a cupola is a great start. Just make sure it is strong enough so a raccoon can’t rip it apart and things can’t limb in through the openings.
In the summer you need an opening lower down to let in cool air. A pop door, a window at or below roost height, or another vent down low are all good. In the heat, it’s next to impossible to have too much. It helps too to have at least one of the openings on the north side or in a shaded area so the air is cooler.
Thanks for the advice! I love that a cupola is functional and looks nice. It will be sturdy and have hardware cloth between the roof opening and saddle because we do have raccoons and others that would enjoy chicken. The actual louvers are 7.5 x 7.5 I'm thinking that will be enough for my small coop. I'll also do as Ridgerunner suggests and add vents in the eaves above roost level and vents I can close down low. I was very happy to find this site as it's been years since I had chickens and a large coop was already there so it is starting from scratch for me. Thanks again!