ABNORMALITY DIAGNOSIS DEVICE FOR BLOWER SYSTEM

An abnormality diagnosis device that performs an abnormality diagnosis on a blower system that sends air to a plurality of air receiving objects obtains a target operating state of an airflow control device that controls airflow to the air receiving objects, obtains a temperature detected by a temperature sensor that detects a first temperature as a temperature of air fed to a first air receiving object as one of the air receiving objects or a temperature of the first air receiving object, estimates the first temperature, based on the target operating state of the airflow control device, and performs abnormality diagnosis on the airflow control device. The abnormality diagnosis device determines that there is an abnormality in the airflow control device, when a difference between the detected first temperature and the estimated first temperature is equal to or larger than a predetermined first reference value.