Abstract: In an air conditioner system for a mobility device, some inside air communicates with an outdoor heat exchanger when outside air for indoor ventilation is introduced, thereby improving heat pump performance. That is, by allowing indoor cold air to communicate with the outdoor heat exchanger upon mixing the inside and outside air during indoor cooling and allowing indoor warm air to communicate with the outdoor heat exchanger upon mixing the inside and outside air during indoor heating, it is possible to increase the heat pump efficiency as the outdoor heat exchanger recovers the heat of the indoor air during indoor cooling and heating. In addition, introduced is an air conditioner system for a mobility device in which a structure is simplified as inside air may be selectively transmitted to an outdoor heat exchanger side only by applying a flow path structure and a valve.