Abstract: It is disclosed a ventilator (9A, 9) comprises a housing (20) having opposite first (21) and second ends (22) and an axial rotor (23) arranged in a ventilator flow path (23A), wherein the ventilator flow path (23A) has an inlet at the first end (21) of the housing (20) and an outlet (22A) at the second end of the housing (20) and wherein an additional flow path (25) is present comprising one or more sensors and which additional flow path (25) fluidly connects an opening (16, 24) in the housing (20) with the ventilator flow path (23A) for drawing in air due to a venturi effect via the additional flow path (25) towards the ventilator flow path (23A), wherein the sensors are temperature and/or humidity sensors.