I am building an incubator and am finding very little information on vents. How much fresh air is needed? Is the air needed to hatch eggs or just regulate the humidity level? Will the humidity fall as the vents are opened? Is more air needed at lock down? Am I over thinking this? Where is the best place for vents, top, down low, behind the fan, on each end? I am useing a 54 quart cooler as my incubator. Thank You all at BYC !!! I have learned so much from this web site and gain more chicken knowlege every day.