Acoustic shielding with cover to be installed on the AHU, sound absorbing and sound insulating, consisting of a self-supporting metal structure to be anchored to the existing concrete slab. Wall and roof cladding with sound-absorbing-insulating modular sandwich-type panels, consisting of an external casing in solid sheet metal, insulating material in mineral rock wool and perforated sheet metal directed towards the noise source. Sound-absorbing and sound-insulating partitions, self-supporting, to be installed as shielding of the AHU return/delivery air outlets without impeding their correct functioning.