An airflow assembly, comprising: a plenum including an opening structure defining a plenum opening; a barrel extending in a downstream direction from said opening structure, and defining a barrel space and a downstream edge; a fan support at least partially positioned within said barrel space; a fan assembly supported by said fan support and including a motor and a blade assembly configured to rotate about an axis; and a plurality of ribs (16a, 16b, 16c), each of said ribs extending between said opening structure or said barrel, and said fan support, wherein said downstream direction is parallel to said axis, wherein an upstream direction is opposite of said downstream direction and parallel to said axis, wherein a plane intersects said axis and is perpendicular to said axis, wherein said downstream edge is of variable axial extent, and includes a first extent portion defining a first edge portion and a second extent portion defining a second edge portion, wherein each rib (16a, 16b, 16c) of said plurality of ribs (16a, 16b, 16c) defines a first azimuthal extent, and extends from said opening structure or said barrel at a corresponding intersection region (38a, 38b, 38c) of said barrel, wherein each of said intersection regions (38a, 38b, 38c) defines a second azimuthal extent, wherein Y equals said first azimuthal extent, wherein X equals said second azimuthal extent, wherein Y ≤ X ≤ 2.5Y, wherein said first extent portion extends between a first intersection region and a second intersection region, wherein said second extent portion extends between said second intersection region and a third intersection region, wherein said airflow assembly is configured to be associated with a vehicle having underhood components, and wherein at least one of said first extent portion and said second extent portion does not serve as an attachment structure or a guiding structure for said underhood components and/or does not accommodate an edge of a reinforcing rib extending between said plenum and said barrel, the airflow assembly being characterised in that said first edge portion is spaced apart from said plane in said upstream direction, and said second edge portion is spaced apart from said plane in said downstream direction. a plenum including an opening structure defining a plenum opening; a barrel extending in a downstream direction from said opening structure, and defining a barrel space and a downstream edge; a barrel extending in a downstream direction from said opening structure, and defining a barrel space and a downstream edge; a fan support at least partially positioned within said barrel space; a fan assembly supported by said fan support and including a motor and a blade assembly configured to rotate about an axis; and a plurality of ribs (16a, 16b, 16c), each of said ribs extending between said opening structure or said barrel, and said fan support, wherein said downstream direction is parallel to said axis, wherein an upstream direction is opposite of said downstream direction and parallel to said axis, wherein a plane intersects said axis and is perpendicular to said axis, wherein said downstream edge is of variable axial extent, and includes a first extent portion defining a first edge portion and a second extent portion defining a second edge portion, wherein each rib (16a, 16b, 16c) of said plurality of ribs (16a, 16b, 16c) defines a first azimuthal extent, and extends from said opening structure or said barrel at a corresponding intersection region (38a, 38b, 38c) of said barrel, wherein each of said intersection regions (38a, 38b, 38c) defines a second azimuthal extent, wherein Y equals said first azimuthal extent, wherein X equals said second azimuthal extent, wherein Y ≤ X ≤ 2.5Y, wherein said first extent portion extends between a first intersection region and a second intersection region, wherein said second extent portion extends between said second intersection region and a third intersection region, wherein said airflow assembly is configured to be associated with a vehicle having underhood components, and wherein at least one of said first extent portion and said second extent portion does not serve as an attachment structure or a guiding structure for said underhood components and/or does not accommodate an edge of a reinforcing rib extending between said plenum and said barrel, the airflow assembly being characterised in that said first edge portion is spaced apart from said plane in said upstream direction, and said second edge portion is spaced apart from said plane in said downstream direction.