Airflow and Duct Planning
Duct / CFM / Airflow Calculator
How much airflow does my AC need?
A common residential airflow target is about 350 to 450 CFM per ton, with 400 CFM per ton as a planning midpoint. Actual airflow depends on blower settings, duct size, return air, filter restriction, static pressure, coil condition, and room layout.
Duct / CFM / Airflow Calculator FAQs
Is 400 CFM per ton always right?
No. It is a planning midpoint. Humidity, equipment, blower setup, and duct design can change the target.
Can a dirty filter reduce CFM?
Yes. A restrictive or packed filter can reduce airflow and create comfort, coil, and efficiency problems.
Can duct cleaning fix airflow?
Sometimes restrictions matter, but duct sizing, leaks, returns, dampers, and equipment condition may be bigger issues.
