The invention concerns a helicopter ventilation architecture, said helicopter comprising at least two avionics bays (112a, 112b) comprising electronic equipment (116a, 116b) to be ventilated, said architecture comprising, for each avionics bay, an air inlet (120a, 120b) allowing outside air to enter the avionics bay in order to ventilate said avionics bay, and an air outlet (124a, 124b), allowing the air ventilating the avionics bay to exit the avionics bay, characterised in that the ventilation architecture further comprises a mixing chamber (134), connected to the air outlets, configured to receive the air originating from all the avionics bays, at least one air duct (138a, 138b), connected to the mixing chamber and to an outlet (130a, 130b) for discharging the air to the outside, and at least two fans (128a, 128b), arranged and distributed in the air duct or ducts.