Tips For Prevent Air-Con Low Air Flow Problems In Car

Low airflow problems can be caused by a dirty cabin air filter, tree leaves in the evaporator case or from the evaporator getting too cold and icing up. Not all cars have cabin air filters for the passenger compartment. Many drivers are unaware that a cabin filter may even be in their car to begin with, that’s the reason they can go for years without being changed. If experiencing low airflow through the dash vents; the cabin air filter, if equipped should be checked. It’s not uncommon even for auto technicians to be unaware if a particular model, is equipped with a cabin air filter. That’s why if you have low airflow it’s worth mentioning the possibility that an air filter could be the problem to the auto technician.

Oak Trees

If the car is routinely parked underneath a tree (especially oak leaves since they’re small) there’s a good chance that leaves can be entering the car’s AC duct-work. It’s a good idea to keep the leaves cleaned off of the cowl area. The cowl area is near the windshield wipers below the windshield. Leaves tend to remain in this area easily. One of the problems with that is, the air-conditioning fresh air entrance is in that area. Many times the leaves get into the air-conditioning ventilation system through the fresh air duct work.

Evaporator Core Icing

If the car AC blows very cold for a short period of time and then blows warm and a lower flow of air is experienced, the evaporator core may be icing up. Sometimes if the expansion valve is not working properly the evaporator gets too cold. This results in the condensation on the evaporator icing up in restricting the airflow through the evaporator fins. The expansion valve is designed to keep the evaporator cold but above the freezing point. One indication if this is occurring, is that the air-conditioning can be turned off for a few minutes (the ice has time melt) and then when it is turned back on it will work again for a few minutes until it ices up again. Another cause of the evaporator icing up can be if there is moisture in the system. If moisture is the problem the A/C dryer may have to be changed and then the system can be evacuated and recharged with a vacuum pump. The drying agent in the dryer along with the evacuation process will remove moisture from the AC refrigerant.