US Patent 9797413 Bladeless ceiling fan

A fan assembly for generating an air flow within a room includes an annular casing which defines an interior passage. The interior passage includes an air inlet, and houses, downstream from the air inlet, an impeller and a motor for driving the impeller to draw an air flow through the air inlet and into the fan assembly. The interior passage also has an air outlet from which at least a portion of the air flow is emitted from the fan assembly. The annular casing defines a bore about which the interior passage extends and through which a secondary air flow from outside the fan assembly is drawn by the air emitted from the air outlet.