Rebel, you make some good points about ventilation and air exchange. One thing you might want to add is air speed. Everybody wants to try and keep the temps even thoughout the incubator. One way to do this is by using a fan. Most figureing that the more air movement the better. This is not true. As the air moves across the eggs, it will have a evaporative effect that pulls moisture out of the egg. This is similar to being all sweaty and standing in front of a fan, as the air moves across your skin you feel a cooling effect as the sweat drys from your body. The same thing occurs with the eggs. Even tho the hygrometer might say you have a 50% humidity, this moisture most likely came from inside the eggs and you can endup with dry, stuck chicks. The key is to create air movement without creating a wind. This is one thing I just dont like about the Dickey and Sportsman cabinet style incubators. They use a large fan to circulate the warm air, across a pan of water to create humidity. All the while, this same fan is blowing that air with a big windspeed that also drys out the eggs that are in the incubator. Yes you have high humidity but where is the moisture coming from. Not all of it is coming from the pan of water at the top of the incubator, some is pulling from the eggs themselfs.
