A fan 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 (F1) and defining therein a first passage for said primary air flow (F1) ; - a first mouth receiving, in use, a first aliquot of said primary air flow (F1) from said first passage ; - a first Coanda surface on which said first mouth directs, in use, said first aliquot of said primary air flow (F1); - a first opening fluidly connected with said first mouth and crossable, in use, by said first aliquot of said primary air flow (F1) coming out of said first mouth and by a secondary air flow (F2) drawn by said primary air flow (F1); 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 (F1); said second conveying element comprising, in turn: - at least one second mouth receiving , in use, said second aliquot of said primary air flow (F1) 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 (F1); said fan further comprising at least one duct fluidly connected with said first and second conveying elements , arranged radially with respect to the axes of said first and second conveying elements and defining a nozzle with a further outlet for said second aliquot of said primary flow (F1); said nozzle being coaxial to said first and second conveying elements 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 (F1) flowing into said second passage directly in a direction parallel to an axis (A) of said fan . - a first annular conveying element , fluidly connectable with a source (120, 121, 122, 123, 203, 205 405, 410, 412) of a primary air flow (F1) and defining therein a first passage for said primary air flow (F1) ; - a first mouth receiving, in use, a first aliquot of said primary air flow (F1) from said first passage ; - a first Coanda surface on which said first mouth directs, in use, said first aliquot of said primary air flow (F1); - a first opening fluidly connected with said first mouth and crossable, in use, by said first aliquot of said primary air flow (F1) coming out of said first mouth and by a secondary air flow (F2) drawn by said primary air flow (F1); 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 (F1); - at least one second mouth receiving , in use, said second aliquot of said primary air flow (F1) 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 (F1); <EOS>