How would go about installing a ceiling fan. In this room
Does not have a ceiling. Just a series of rafters. Would you need to built a platform? There is an electric line near by that could be fished in by conduit but what about the swing of the fan blades?? If it was to be installed between the rafter

I would cut a short piece of 2x4 or 2x6, your choice, depending on the weight of the fan, the width of the inner space between rafters, and use heavy long screws going in through the side of the rafters to mount it in a horizontal poisition, flush with the lowest surface, like an "H" shape. Then do the wiring and mount the fan. You may cut a hole in the new piece for wiring or just go around the edge, what ever you prefer.