A flush-mounted fan system of an industrial ventilation system, comprising: - a fan device comprising a blade group commandable in rotation about a main axis (X-X) and an electric motor group extending along the main axis (X-X) comprising: i) a drive shaft extending along said main axis (X-X) having a blade end to which the blade group is solidly connected; ii) an electric motor comprising a rotor of the external rotor type and a stator, wherein the rotor is operatively connected to the drive shaft iii) an electronic command device of the electric motor positioned along the main axis (X-X); wherein the electric motor comprises a motor body defining, along the main axis (X-X), a motor casing housing the electric motor and a command casing housing the electronic command device, wherein the motor casing is comprised between the blade group and the command casing; wherein the electric motor comprises a rotor bell on which the rotor is housed, wherein the rotor bell is housed in the motor casing, wherein said drive shaft is solidly connected to said rotor bell such that a rotation of the rotor bell corresponds to a rotation of the drive shaft; - a flush-mounted frame housing the fan device comprising: m) a flush-mounted box defining a through opening identifying an opening center; n) a bracket group housed in the through opening supporting the fan device in such a way that the main axis (X-X) and the opening center correspond. - a fan device comprising a blade group commandable in rotation about a main axis (X-X) and an electric motor group extending along the main axis (X-X) comprising: i) a drive shaft extending along said main axis (X-X) having a blade end to which the blade group is solidly connected; ii) an electric motor comprising a rotor of the external rotor type and a stator, wherein the rotor is operatively connected to the drive shaft iii) an electronic command device of the electric motor positioned along the main axis (X-X); wherein the electric motor comprises a motor body defining, along the main axis (X-X), a motor casing housing the electric motor and a command casing housing the electronic command device, wherein the motor casing is comprised between the blade group and the command casing; wherein the electric motor comprises a rotor bell on which the rotor is housed, wherein the rotor bell is housed in the motor casing, wherein said drive shaft is solidly connected to said rotor bell such that a rotation of the rotor bell corresponds to a rotation of the drive shaft; i) a drive shaft extending along said main axis (X-X) having a blade end to which the blade group is solidly connected; ii) an electric motor comprising a rotor of the external rotor type and a stator, wherein the rotor is operatively connected to the drive shaft iii) an electronic command device of the electric motor positioned along the main axis (X-X); wherein the electric motor comprises a motor body defining, along the main axis (X-X), a motor casing housing the electric motor and a command casing housing the electronic command device, wherein the motor casing is comprised between the blade group and the command casing; wherein the electric motor comprises a rotor bell on which the rotor is housed, wherein the rotor bell is housed in the motor casing, wherein said drive shaft is solidly connected to said rotor bell such that a rotation of the rotor bell corresponds to a rotation of the drive shaft; wherein the electric motor comprises a motor body defining, along the main axis (X-X), a motor casing housing the electric motor and a command casing housing the electronic command device, wherein the motor casing is comprised between the blade group and the command casing; wherein the electric motor comprises a rotor bell on which the rotor is housed, wherein the rotor bell is housed in the motor casing, wherein said drive shaft is solidly connected to said rotor bell such that a rotation of the rotor bell corresponds to a rotation of the drive shaft; - a flush-mounted frame housing the fan device comprising: m) a flush-mounted box defining a through opening identifying an opening center; n) a bracket group housed in the through opening supporting the fan device in such a way that the main axis (X-X) and the opening center correspond. m) a flush-mounted box defining a through opening identifying an opening center; n) a bracket group housed in the through opening supporting the fan device in such a way that the main axis (X-X) and the opening center correspond.