That is one thing people will tell you on this website is dont over think things, they are just chickens so keep it simple. You dont need to exchange all the air with fresh every hour or anything like that. If you look at most store bought incubators there are not many air holes and they are not very big. I have plugs to block some of mine if needed but if you have a few and it holds temps ok you are probably good. I had 21 chicks in mine and no problems with moisture or with the chicks panting. Just keep eye on first hatch and adjust IF needed.