Increased air flow in ducts can be achieved by cleaning air filters and ducts. Follow the ducts in your attic, starting near the heating unit. Check for restrictions in the ducts, either by sharp curves or by maceration. Correct any sharp bends by adjusting the duct to create an arc, not an acute angle.
Remove any objects that have fallen into the duct and change the shape of any shredded areas of the flexible duct. Replace any area with significant damage. If the ducts have cracks, holes, or seams that cause air leakage, this can affect airflow. Instead of blowing steadily and steadily through the ducts and out through the vents, air escapes through those cracks and reduces the amount of air that reaches the vents.
If you want to keep airflow and your system clean, the best thing to do is perform maintenance tasks such as cleaning and replacing filters, monitoring dampers, keeping vents clear, and protecting flex ducts from damage.