A fan is described with a first conveying element, fluidly connectable with a source of a primary air flow and defining a first passage for the primary air flow; a first mouth receiving a first aliquot of the primary air flow from the first passage; a first Coanda surface onto which the first mouth directs the first aliquot; and a first opening fluidly connected with the first mouth and crossable by the first aliquot coming of the first mouth and a secondary air flow; the fan comprises a second conveying element, fluidly connected with the first conveying element and defining internally a second passage for a second aliquot of the primary air flow, and comprises: a second mouth receiving the second aliquot from the second passage and a second Coanda surface onto which the second mouth directs the second aliquot.