Why does the car air conditioner's airflow decrease after prolonged use?

[DeMiles]

There are several possible reasons why the airflow of a car air conditioner decreases after prolonged use: 1. Blower issues: The blower may have a short circuit or overheat. It is recommended to visit a car 4S shop for repair, as weak airflow not only reduces cooling efficiency but also consumes more energy. 2. Condenser blockage: This can cause a sudden decrease in airflow, requiring immediate cleaning or replacement of the filter. 3. Damaged air duct fan: If the air duct cannot open properly, it will result in reduced airflow. 4. Dirty air filter: A clogged filter obstructs airflow, allowing only partial air to pass through.

[Connor]

The air flow becomes weaker after prolonged AC use, which I've encountered several times in my own car. Usually, it's because the air filter is too dirty and clogged. After extended operation, dust accumulates in the filter, obstructing airflow. Another issue is evaporator icing—when the AC runs continuously, condensed water freezes in the pipes, blocking the vents. I remember once during a long summer drive, the AC airflow suddenly weakened. After stopping to check, I found the evaporator had iced up. Turning off the AC to let the ice melt helped significantly. To prevent this, I recommend replacing the filter every six months and having the evaporator cleaned during maintenance. Additionally, aging or leaking pipes can also reduce airflow. In short, weaker airflow isn't just a minor issue—it can affect cooling efficiency in the cabin, so don't delay addressing it.

[McOlive]

When the air conditioning airflow decreases, I often associate it with blower issues. Under prolonged operation, the motor is prone to overheating or wear, causing the fan wheel to rotate less smoothly. Once during a car repair, the mechanic said it was due to a faulty blower. Clogged filters are also a major cause, especially in dusty urban areas. When inspecting, I usually listen for unusual fan noises—any odd sounds should raise concern. Frozen pipes or system leaks can also weaken airflow. I recall that insufficient coolant reduces AC efficiency, so I recommend checking if the filter is clean yourself. If not, take it to a professional shop for a circuit inspection. Regular maintenance can prevent these issues, such as cleaning the filter every three months to avoid discomfort during long trips. It's normal for older cars to develop such problems—fixing them early prevents bigger issues later.

[McFernando]

Reduced airflow after prolonged AC use is commonly due to a clogged air filter. In my experience, accumulated dust on the filter restricts airflow. Icing on the evaporator can also block air passage—turning the AC off and on briefly allows the ice to melt. When the blower malfunctions, airflow decreases, often accompanied by unusual fan noises. A simple solution is to inspect and replace the filter. If issues persist, it could indicate duct leaks or electrical problems. Regular system maintenance checks are recommended. Poor airflow affects cabin temperature, so early repairs ensure peace of mind.