Why does air filters used in automobiles and furnaces must be changed regularly?

Air filters in automobiles and furnaces must be changed regularly to ensure optimal performance and efficiency. Over time, filters accumulate dust, dirt, and debris, which can restrict airflow and lead to reduced efficiency, increased fuel consumption, and potential damage to the engine or heating system. Regular replacement helps maintain clean air quality and prolongs the lifespan of these systems, ultimately saving on repair costs and improving overall functionality.