Furnace filters do a lot more work then what you really think.
Furnace filters are responsible to reduce smoke, pollen, bacteria, dust, dust mites, pet dander and more from the air you breathe.
Filter replacement is quite inexpensive but it helps your furnace maintain proper airflow. The filters are designed to catch particles and dirt that would cause considerable damage to your furnace if they were not captured in the filtering process.
Furnace filters help improve the air quality inside your home. However, the problem is that once they become full of dirt they can block airflow and negatively impact the efficiency of your air system.