Ceiling Fan Size Guide — Sweep, Room Size and Mounting

• Height: the blades should sit about 9-10 ft above the floor. Higher and the air disperses before it reaches you; lower and it is unsafe and uncomfortable.
• Wall clearance: at least about a foot from the blade tip to the nearest wall or cupboard, or the fan buffets and is noisy.
• High ceilings: use a longer downrod rather than accepting a fan 14 ft up. A fan near the roof circulates air nobody is standing in.
• Low or false ceilings: use a hugger or low-profile fan, which mounts flush with no downrod. The designer brands cover this far better than the mass brands do.

A single ceiling fan throws air usefully over roughly a 12-15 ft circle. Beyond that the far corners of the room get very little, whatever the fan's CMM. For a hall longer than about 18 ft, two fans spaced along the length will feel dramatically better than one large fan in the middle — and two 1,200 mm BLDC fans at 30 W each still draw less than one old 75 W induction fan.