A modular element for dynamic air curtain barriers, said modular element comprising: - at least one supporting tubular frame extending along a prevalent direction of extension between a first and a second longitudinal end (3a, 3b), said supporting frame having a lateral wall internally defining a housing compartment and which defines, at the first and second ends (3a, 3b) of the frame, a respective first and second longitudinal openings (6, 7), the first and second longitudinal openings (6, 7) being delimited by respective free edges (6a, 7a), the supporting frame further comprising at least one lateral through opening substantially extending along the prevalent direction of extension of the frame itself, the supporting frame being associable with at least one ventilating device configured to generate an air flow destined for the housing compartment of the frame itself and passing through at least one of said first and second longitudinal openings (6, 7), - at least one channel engaged with the supporting frame and configured to receive the air flow from the ventilating device and channel it along a direction of ejection out of said housing compartment through the lateral opening, the modular element characterized in the channel having at least a first and a second longitudinal channelling wall (10, 11) extending prevalently, or completely, inside the housing compartment along the prevalent direction of extension of the frame, each channelling wall (10, 11) having at least one inlet portion (10a, 11a) located inside the housing compartment and an outlet portion (10b, 11b) preferably, but not necessarily, located outside the housing compartment, the respective inlet portions (10a, 11a) of the channelling walls (10, 11) defining a lateral inlet opening, the respective outlet portions (10b, 11b) of the channelling walls (10, 11) defining an outlet opening configured to direct the air flow along the ejection direction, the channelling walls (10, 11) defining, in cooperation with each other, a duct for the air flow extending between the inlet opening and the outlet opening, and wherein the inlet portions (10a, 11a) of the channelling walls have a minimum distance from the lateral opening that is greater than a minimum distance present between the same inlet portions (10a, 11a) and a portion of the lateral wall of the frame opposite the lateral opening. - at least one supporting tubular frame extending along a prevalent direction of extension between a first and a second longitudinal end (3a, 3b), said supporting frame having a lateral wall internally defining a housing compartment and which defines, at the first and second ends (3a, 3b) of the frame, a respective first and second longitudinal openings (6, 7), the first and second longitudinal openings (6, 7) being delimited by respective free edges (6a, 7a), the supporting frame further comprising at least one lateral through opening substantially extending along the prevalent direction of extension of the frame itself, the supporting frame being associable with at least one ventilating device configured to generate an air flow destined for the housing compartment of the frame itself and passing through at least one of said first and second longitudinal openings (6, 7), - at least one channel engaged with the supporting frame and configured to receive the air flow from the ventilating device and channel it along a direction of ejection out of said housing compartment through the lateral opening,