One ton of cooling typically requires 400 Cubic Feet per Minute (CFM) of airflow.
💡 Many homeowners use a "trunk and branch" system—rigid sheet metal for the main trunk line and short flex runs for the final branches to the vents. 3. The Budget: What to Expect
Replacing ducts in an unfinished basement is cheapest ($10/ft). Cutting through finished walls is most expensive ($40–$70/ft).
