Axial fan

An axial fan comprising:

• a motor including a shaft arranged to extend along a central axis extending in a vertical direction;
• an impeller fixed to the shaft, and arranged to be capable of rotating about the central axis;
• and
• a housing including an air channel wall portion being tubular, extending in an axial direction, and arranged radially outside of the impeller;
• wherein
• the impeller includes:
• a tubular impeller hub directly or indirectly fixed to the shaft;
• and
• a plurality of blades arranged in a circumferential direction on an outer surface of the impeller hub;
• each blade includes a first portion where all of an inner circumferential developed blade, an outer circumferential developed blade, and an intermediate circumferential developed blade superimposed on each other overlap when viewed in a radial direction, the inner circumferential developed blade being a circumferential development of a junction of the blade with the outer surface of the impeller hub, the outer circumferential developed blade being a circumferential development of a radially outermost portion of the blade, the intermediate circumferential developed blade being a circumferential development of a radially intermediate portion of the blade between the junction and the radially outermost portion of the blade;
• and
• the radially outermost portion of the blade is at a shortest radial distance from an inner surface of the air channel wall portion in at least a portion of the first portion.