What are the reasons for weak airflow from the BMW 3 Series air vents?

[Curtis]

BMW 3 Series air vents have weak airflow for the following reasons: 1. Incorrect air direction setting: If the air vent direction is set to blow toward the windshield, the airflow will noticeably decrease. 2. Blower motor malfunction: Common blower motor issues include failure to operate, abnormal noise, short circuits, or insufficient power. When the blower motor malfunctions, cold air from the vehicle's air conditioning evaporator cannot be distributed, leading to evaporator icing and ultimately affecting the normal operation of the car's air conditioning system. 3. Condenser or evaporator blockage: If the condenser's exterior or evaporator is clogged with debris such as willow catkins or dust, the condensation efficiency will decline, ultimately affecting the car's cooling performance. Excessive dirt buildup on the evaporator surface can also significantly reduce the air conditioning's cooling effectiveness. 4. Dirty air conditioning filter: If the car's air conditioning filter is excessively dirty, airflow from the vents can be obstructed, allowing only a portion of the air to enter the cabin. As a result, the airflow will feel noticeably weaker.