When I set up a barn that I had at a past operation I had designed with 12x12 stalls on opposite sides of a 16 foot wide aisle. I put 56 inch fans maybe four or five feet in from the front stall walls and over the full height dividing stall walls. My thought was to cover two stalls with one fan but to also allow for some area to have less air flow. The barn was built with no trusses. Rather, there were collar ties over the central aisle and rafters over the stalls so the fans had no restrictions to their flow pattern.
My idea worked very well but if was to do it over, I would have had cages over the fan blades. Bats used to hit the blades and end up dead on the stall floors. And yes, being about 12 feet up, the fans took some work to clean.