The present invention provides a heat exchanger unit that can appropriately inhibit freezing of a heat exchange element even in cold climates. The heat exchanger unit performes heat exchange and ventilation between an indoor space and an outdoor space, and is provided with a heat exchange element, a supply air passage and an exhaust air passage that are routed via the heat exchange element, a temperature sensor, and a control unit. The temperature sensor detects the outside air temperature. The control unit executes a first freeze inhibit control mode, which inhibits freezing of the heat exchange element, if the outside air temperature falls below a first level, and a second freeze inhibit control mode, which inhibits freezing of the heat exchange element more strongly than the first freeze inhibit control mode, if the outside air temperature falls below a second level, which is lower than the first level.