Air conditioning system, and railroad train provided with same

An air conditioning system (1) is provided with an air conditioning duct (4) that is provided to a railroad car (2). The air conditioning duct (4) comprises a ventilation passage (4a) that extends in the longitudinal direction, and a nozzle (4c) linking the ventilation passage (4a) with the car interior (2a), and is configured in such a manner that conditioned air is supplied by an air conditioner (3) to the ventilation passage (4a). Furthermore, flow rate adjustment baffles (6) are provided to the ventilation passage (4a). The flow rate adjustment baffles (6) are in the vicinity of the location where the flow rate of conditioned air is quickest in the longitudinal direction, and are positioned on the downstream side of said location, and are configured in such a manner as to adjust the flow rate by inhibiting the flow of conditioned air inside the ventilation passage (4a).