What Are the Reasons for Insufficient Airflow from Car Air Conditioning?
4 Answers
If the airflow is relatively small when using the external circulation mode but normal when using the internal circulation mode, it is likely due to a clogged cabin air filter. In this case, replacing the cabin air filter with a new one should resolve the issue. If the airflow remains small regardless of the circulation mode, it may involve issues such as internal air duct flaps. This situation is less common than the former. It is recommended to first check the cabin air filter. Replace the cabin air filter if it is too dirty and blocking the airflow into the car. When the refrigeration system is operating, the refrigerant circulates in different states within this closed system, with each cycle consisting of four basic processes: 1. Compression process: The compressor inhales low-temperature, low-pressure refrigerant gas from the evaporator outlet and compresses it into high-temperature, high-pressure gas, which is then discharged from the compressor. 2. Heat dissipation process: The high-temperature, high-pressure superheated refrigerant gas enters the condenser, where the pressure and temperature decrease, causing the refrigerant gas to condense into a liquid and release a significant amount of heat. 3. Throttling process: The higher-temperature and higher-pressure refrigerant liquid passes through the expansion device, where its volume increases, and the pressure and temperature drop sharply, exiting the expansion device as a mist (fine liquid droplets).
There are quite a few reasons for insufficient airflow from the car's air conditioning, and I've encountered it several times myself. The most common issue is a dirty cabin air filter, clogged with dust that blocks air intake and outflow, preventing proper airflow. Another possibility is an aging blower motor, where the fan blades inside have worn out, reducing speed and resulting in weak airflow. Blocked air ducts are also common, such as leaves falling into the vents and accumulating in the tubes. Sometimes, a faulty AC switch or control module can cause issues, where pressing the buttons doesn’t change the airflow. I recommend first checking the filter—replacing it usually solves the problem. If that doesn’t help, inspect the blower or clean the ducts. Regular maintenance is crucial; replacing the filter once a year can prevent weak airflow issues, ensuring comfortable and safe driving with strong airflow.
My old car once had weak air conditioning airflow. At first, I thought it was due to poor cooling performance in hot weather, but then I noticed the vents were barely blowing any air. After some investigation, I found the air filter was clogged, dirty as a mud ball, blocking the airflow. The blower motor might also be faulty—if the motor burns out and stops spinning, the vents will only produce a weak breeze. Another possibility is blockage in the air ducts; once, a tree branch got stuck inside and caused trouble for days. Control panel issues are rare, but if the switch has poor contact, adjusting the fan speed won’t work. In the end, I spent a little money replacing the filter, and it worked fine again. Now, I clean the AC vents every six months. Remember, when airflow is insufficient, don’t force it—opening the windows is more refreshing. Otherwise, the cabin gets stuffy and uncomfortable, affecting your driving.
I had just started driving when I encountered very weak airflow from the AC, initially thinking my old car had broken down. Later, I learned that the cabin air filter had accumulated too much dust, blocking the airflow. A stuck blower fan can also reduce airflow, especially noticeable at low speeds. If debris like toys or leaves gets stuck in the ducts, the air won't flow properly. Sometimes, improperly adjusted controls can create the illusion of a malfunction. I recommend checking the filter first—it's simple and cost-effective to replace it yourself. If that doesn't work, then visit a repair shop. Keeping your AC system clean can prevent these issues, and always drive safely without distractions.
