I have an ExoTerra incubator, just finished a hatch with it. Loved it held gteat humidity, and temp was steady all along. Its basically a still air, and there is a difference between shelves in temp. I would like to add a fan so I can use more space in it. I'm collecting eggs from my sex link girls to incubate in the next few days. The bator has a fan in the bottom area that only runs when it has to heat up some....the fan sucks air in from the bottom and out through the top where the heating element is. Where should I put a fan? On the side blowing across the top to the other side? Or......?