A fan (10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h) comprising: - a first annular conveying element, fluidly connectable with a source (120, 121, 122, 123, 203, 205 405, 410, 412) of a primary air flow and defining therein a first passage for said primary air flow; - a first mouth receiving, in use, a first aliquot of said primary air flow from said first passage; - a first Coanda surface on which said first mouth directs, in use, said first aliquot of said primary air flow; - a first opening fluidly connected with said first mouth and crossable, in use, by said first aliquot of said primary air flow coming out of said first mouth and by a secondary air flow drawn by said primary air flow; and - at least one second annular conveying element, fluidly connected with said first conveying element and defining therein a second passage for a second aliquot of said primary air flow; said second conveying element comprising, in turn: - at least one second mouth receiving, in use, said second aliquot of said primary air flow from said second passage and fluidly connected with said opening; and - at least a second Coanda surface onto which said second mouth directs, in use, said second aliquot of said primary air flow; said fan (10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h) further comprising at least one duct fluidly connected with said first and second conveying elements (11, 30), arranged radially with respect to the axes of said first and second conveying elements (11, 30) and defining a nozzle with a further outlet for said second aliquot of said primary flow; said nozzle being coaxial to said first and second conveying elements (11, 30) and radially inward of said second conveying element; characterized in that said second conveying element comprises a pair of said second mouths and a pair of said second Coanda surfaces facing respectively towards said first conveying element and towards an axis of said first conveying element; said nozzle making it possible to eject, in use, a quantitatively residual aliquot of said primary flow flowing into said second passage directly in a direction parallel to an axis of said fan (10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h). - a first annular conveying element, fluidly connectable with a source (120, 121, 122, 123, 203, 205 405, 410, 412) of a primary air flow and defining therein a first passage for said primary air flow; - a first mouth receiving, in use, a first aliquot of said primary air flow from said first passage; - a first Coanda surface on which said first mouth directs, in use, said first aliquot of said primary air flow; - a first opening fluidly connected with said first mouth and crossable, in use, by said first aliquot of said primary air flow coming out of said first mouth and by a secondary air flow drawn by said primary air flow; and - at least one second annular conveying element, fluidly connected with said first conveying element and defining therein a second passage for a second aliquot of said primary air flow; - at least one second mouth receiving, in use, said second aliquot of said primary air flow from said second passage and fluidly connected with said opening; and - at least a second Coanda surface onto which said second mouth directs, in use, said second aliquot of said primary air flow;