Hang fans about 8 feet above the floor for the maximum cooling effect. For rooms with high ceilings, purchase a just-the-right-size downrod by subtracting 8 feet from the ceiling height and adding back about 1 foot to accommodate the motor and casing. If your headroom is less than 9 feet, choose a hugger-style ceiling fan, which has a more compact shape. Sloped ceiling? Manufacturers sell adapters that let fans hang at an angle of up to 48 degrees.