First of all, before taking care of the ventilation system in your house, you should choose a good ventilation system that will not show any issues at least the first 5 years since you purchased it. I have a list with
the best exhaust fans that help keeping the house fresh every day, that also protect the roof by keeping it cold and the prices are very good. I will attach you a link and you may get convinced by yourself by the great effects it has.