A cleaning unit is provided comprising: a containment chamber (2) defining an accumulation base (10), a suction apparatus (3) including a suction inlet (6) positioned close to the ground, and a filtering apparatus (12), the suction apparatus (3) comprising primary suction means (4) and secondary suction means (5) positioned in parallel to one another above the accumulation base (10), the primary suction means (4) controlling said suction inlet (6) and the secondary suction means (5) being suitable to expel filtered air, and the containment chamber (2) including separating element (9) which separates the turbulent zone (5a), the air inside of which being highly turbulent, and a recirculation zone (4a), the air inside of which having a low turbulence, the recirculation zone (4a) being connected to the primary suction means (4) and the turbulent zone (5a) being connected to the secondary suction means (5).