Abstract: An air filter system in accordance with the present invention includes a filter housing that defines an airflow channel. A supply roll of a filter medium, and a take-up roll for receiving the filter medium from the supply roll are positioned parallel to each other in the airflow channel. A plurality of wire mesh diverter-screens are positioned between the supply roll and the take-up roll to establish a tortuous path for statically positioning the filter medium across the airflow channel. Periodically, the take-up roll can be rotated to draw replacement filter medium into position on the tortuous path.