A blower fan comprises a support element (13) presenting a first face (13a) and a second face (13b) mutually opposite to said first face (13a), the first and the second faces (13a, 13b) being respectively invested at least by a first and a second air flows (10, 11) coming from mutually opposite directions, a first blade series emerging at least from said second face (13b), and at least one air passage (13c) provided in the support element (13) and adapted to direct at least said first air flow (10) investing said first face (13a) at least partly through said support element (13).