A reaction turbine intended to create an air flow, by rotation on itself, of the type including: - a lower flange and an upper flange, each having a generally annular shape, and substantially parallel to each other and perpendicular to the axis of rotation (X-X); - a plurality of blades (8, 9, 10, 11, 12, 13, 14) disposed between the two flanges (6, 7), of an arcuate shape such that: - the trailing (82, 92, 102, 112, 122, 132, 142) and leading (83, 93, 103, 113, 123, 133, 143) edges are inclined relative to the parallel planes of the flanges (6, 7); - the inclination of the blades (8, 9, 10, 11, 12, 13, 14), relative to the axis of rotation (X-X), varies from the leading edge (83, 93, 103, 113, 123, 133, 143) to the trailing edge (82, 92, 102, 112, 122, 132, 142); - the leading (83, 93, 103, 113, 123, 133, 143) and trailing (82, 92, 102, 112, 122, 132, 142) edges have respective different inclinations relative to the axis of rotation (X-X); the turbine being made by moulding, in plastic material, one of the flanges (6, 7), preferably the lower flange, on the one hand, and the blades (8, 9, 10, 11, 12, 13, 14), on the other hand, being made in one single piece, characterised in that for each blade (8, 9, 10, 11, 12, 13, 14), the angle (delta) (Δ), called "trailing edge pitch" angle, formed by, on the one hand, the straight line passing through the trailing edge (82, 92, 102, 112, 122, 132, 142) and the leading edge (83, 93, 103, 113, 123, 133, 143), and, on the other hand, the straight line passing through the tangent to the circle of displacement of the trailing edge and the trailing edge (82, 92, 102, 112, 122, 132, 142), is comprised between 22.5° and 29.7°, and in that the blades (8, 9, 10, 11, 12, 13, 14) are disposed angularly, seen in a diametrical plane orthogonal to the flow of air, in a distribution which is not uniform, that is to say that the angular sector separating the leading edge (83, 93, 103, 113, 123, 133, 143) of a blade (8, 9, 10, 11, 12, 13, 14) from the leading edge of the next blade is different from 360°/n, "n" being the number of blades, and the separation angles of two consecutive blades have a global variation between the smallest angle and the largest angle of about 30%. - a lower flange and an upper flange, each having a generally annular shape, and substantially parallel to each other and perpendicular to the axis of rotation (X-X); - a plurality of blades (8, 9, 10, 11, 12, 13, 14) disposed between the two flanges (6, 7), of an arcuate shape such that: - the trailing (82, 92, 102, 112, 122, 132, 142) and leading (83, 93, 103, 113, 123, 133, 143) edges are inclined relative to the parallel planes of the flanges (6, 7); - the inclination of the blades (8, 9, 10, 11, 12, 13, 14), relative to the axis of rotation (X-X), varies from the leading edge (83, 93, 103, 113, 123, 133, 143) to the trailing edge (82, 92, 102, 112, 122, 132, 142); - the leading (83, 93, 103, 113, 123, 133, 143) and trailing (82, 92, 102, 112, 122, 132, 142) edges have respective different inclinations relative to the axis of rotation (X-X); the turbine being made by moulding, in plastic material, one of the flanges (6, 7), preferably the lower flange, on the one hand, and the blades (8, 9, 10, 11, 12, 13, 14), on the other hand, being made in one single piece, characterised in that for each blade (8, 9, 10, 11, 12, 13, 14), the angle (delta) (Δ), called "trailing edge pitch" angle, formed by, on the one hand, the straight line passing through the trailing edge (82, 92, 102, 112, 122, 132, 142) and the leading edge (83, 93, 103, 113, 123, 133, 143), and, on the other hand, the straight line passing through the tangent to the circle of displacement of the trailing edge and the trailing edge (82, 92, 102, 112, 122, 132, 142), is comprised between 22.5° and 29.7°, and in that the blades (8, 9, 10, 11, 12, 13, 14) are disposed angularly, seen in a diametrical plane orthogonal to the flow of air, in a distribution which is not uniform, that is to say that the angular sector separating the leading edge (83, 93, 103, 113, 123, 133, 143) of a blade (8, 9, 10, 11, 12, 13, 14) from the leading edge of the next blade is different from 360°/n, "n" being the number of blades, and the separation angles of two consecutive blades have a global variation between the smallest angle and the largest angle of about 30%.