What Causes Uneven Airflow from Car Air Conditioning Vents?
3 Answers
If the airflow is weaker when using the external circulation mode but normal with internal circulation, it is likely due to a clogged cabin air filter. In this case, replacing the cabin air filter should resolve the issue. Internal Air Duct Flap Issue: If the airflow remains weak regardless of the circulation mode, it may indicate problems with the internal air duct flap or similar components. This situation is less common than the previous one. It is recommended to first inspect the cabin air filter. Replacing a dirty air filter that is obstructing airflow into the vehicle may solve the problem. How Car Air Conditioning Works: The car air conditioning refrigeration system consists of a compressor, condenser, receiver-drier, expansion valve, evaporator, and blower motor. These components are connected through copper (or aluminum) pipes and high-pressure rubber hoses to form a sealed system. When the refrigeration system operates, the refrigerant circulates through this closed system in different states.
Recently, while driving my old car, I noticed that the airflow from the air vents keeps fluctuating between strong and weak, which is really annoying. The main reason is that the filter is too dirty or clogged, especially after driving for a long time in dusty urban areas where dust accumulates unevenly, causing some vents to have smooth airflow while others are blocked. Additionally, the blades of the blower fan might be deformed or unbalanced, leading to loud noise and unstable airflow at high speeds. Sometimes, foreign objects like small leaves or paper scraps get stuck in the ducts, also causing uneven airflow. I’ve also encountered issues with the damper control assembly, which wasn’t adjusting properly. It’s best to regularly clean the filter and check the ducts; otherwise, it wastes electricity and affects cooling, making long summer drives uncomfortable. I save money by buying tools and cleaning it myself. In short, these minor issues aren’t too complicated, but they should be addressed promptly to avoid turning into bigger problems.
After driving for several years, I often notice inconsistent airflow from the air vents, which is quite annoying. The key issue might be the aging or malfunctioning of the fan motor, causing uneven operation and reduced airflow in certain vents. A clogged filter is a common factor, but if it's only partially blocked, it leads to uneven airflow. Poor duct design or improper installation can also have an impact, such as excessive aftermarket soundproofing materials obstructing airflow. When the control switch circuit has poor contact, it randomly adjusts the air flaps. I've found that rainy days can cause water accumulation in the ducts, leading to uneven airflow. Although this issue isn't urgent, if one side is too hot and the other too cold when using the heater in winter, it can easily distract the driver. It's recommended to inspect and replace parts early to prevent the problem from worsening and disrupting travel plans. Usually, checking the vents when parking can reveal some surprises.
