How to Calculate Duct Airflow

Air ducts deliver air and heating to various rooms in houses and buildings.
••• Jupiterimages/ Images

All heating, air conditioning and ventilation systems use ducting to deliver air from the heating or AC units to the desired locations inside homes and buildings. In addition, ducts also carry air out as required for some venting and air circulation operations. Duct airflow is proportional to the required air speed and the cross-sectional area of the ducting system. For this reason, as the duct size increases, the airflow increases.

    Find the air velocity, or "v," required by the facility your duct system supports in units of meters per seconds. Refer to the facility drawings or specifications.

    Find the cross-sectional area, or "A," of the ducting system in units of square meters. Refer to design specifications for your ducting system.

    Calculate the duct air flow, or "q," using the formula: q = v x A. For example, if v is 15 m/s and the A is 8 square meters, q is 120 cubic meters per second or 120 m^3/s.

Related Articles

What Is a Centrifugal Blower?
Advantages & Disadvantages of Pneumatic Systems
How to Calculate Air Flow Rates
How to Calculate Condensate Flow From AC Units
How to Calculate Orifice Size
How to Convert G/Sec to CFM
How to Calculate Three Phase Amps From Megawatts
Parking Garage Square Footage Per Car
How to Calculate Airflow With Dust Extraction
How to Convert Gallons, Quarts, Pints and Cups
How to Increase Heat Pump Efficiency
How to Calculate Piston Force
How to Reset a Home AC Unit
How to Calculate the Ventilation Rate for a Confined...
What Is the Unit for Enthalpy?
How to Calculate Fundamental Frequency
How to Calculate CFM Output
Advantages & Disadvantages of Rotary Screw Air Compressors
The Four Forces That Influence Wind Speed & Wind Direction
How to Convert Stokes to Poise