I think I remember something about placing a smokey a certain distance from a fan.
The fan moves air from bottom to top, or vice versa in winter.
As the air circulates, it will not move as much; close to the ceiling above the fan, as well as the upper and lower corners of the room.
If you wish the best placement, use a cigarette or smoke source, and see where the smoke curls in the greatest concentration at the ceiling.
