As I was looking at incubators and read that a lot of them (I forgot the exact term) had a fan or had circulating air in them, and not still standing air...? Does that make sense, do you know what I am talking about? Does having still standing air or circulating air fan really make a difference? (creating plans to attempt making an incubator, then testing it for a few days to see how it works before getting eggs!!) Thanks!