Abstract: The apparatus is capable of depurating the air of small-sized ambients or oms, such as kitchens, rooms situated on board of vehicles, etc. and it comprises a housing A for a ventilator or fan 10-12 having a vertical axis and which shows two distributing chambers 16-28. The said chambers are in communication with the room and with the atmosphere and, through commutatable intercepting members 22-38, with the delivery and the intake of the ventilator, while part of the openings of the above mentioned distributing chambers are provided with heat sources 20-46, either to heat or to cool the air which is insufflared into the ambient or room concerned.