On the Fans:
I used to use a box fan in the coop but decided it was to
dangerous fire-wise since those aren't an enclosed motor and with all the dust in a chicken/barn environment I feel that they are a fire waiting to happen.
I got an :"industrial" fan that is used for garages/workshops/barns instead. During the really hot nights mine runs all night so I feel that it is much safer.
Mine is like this one:
http://www.menards.com/main/fans/commercial-fans/14-industrial-floor-fan/p-1933643-c-12728.htm
Edited to clarify - they DO make industrial, enclosed motor box fans too!
I've just never seen one that I could get from the local stores and I was assuming folks would think of the box fans that are meant for indoor use that you get at the local walmart, meijer, etc.... which shouldn't be used in dusty barn-type conditions.