The present invention provides a cooling system. The system comprises a circumferential edge forming an aperture and an axial fan arranged at least partly within the aperture. The axial fan comprises a hub being adapted for rotation about an axis and carrying a plurality of blades. Each blade extends in a radial direction between a root end and a tip end, where the root end is joined with the hub. The system further comprises brushes extending from the tip end towards the circumferential edge, where the brushes at a first end are attached to at least one of the blades at a point of attachment at a distance from the tip end. The brushes overlap the blade from the attachment point to the tip end along the length of the brushes at a pressure side or suction side of the blade.