Device for reducing the noise of motor vehicle air conditioning units

A device for reducing noise of motor vehicle air conditioning units, the device comprising:

• a radial fan, in which a driven fan wheel draws in air via an axial air inlet opening and the air drawn in is conveyed from an interior of the fan via a fan tongue to an air outlet opening, wherein a recirculation air flap is arranged pivotably at least in some areas over the axial air inlet opening in such a way that an air flow on an inside of the recirculation air flap can be deflected in a direction of the axial air inlet opening, the device further comprising:
• at least one air flow limiting element which projects laterally on an outer circumference of the axial air inlet opening vertically out of an air inlet opening plane and thereby has a surface which limits or blocks a flow path next to the axial air inlet opening;
• at least two plate-shaped air guiding elements, which are arranged on the inside of the recirculation air flap in parallel planes at right angles to an axis of rotation of the recirculation air flap;
• and
• an air flow guiding element arranged on the fan tongue, which extends radially from the fan tongue at a distance from the fan wheel into a spiral flow channel.