Sponsored Links

Imperial Units

The velocity of air in a ventilation duct can be expressed in imperial units like

v_i = q_i / A_i = 576 q_i / (π d_i²) = 144 q_i / (a_i b_i)         (1)

where

v_i = air velocity (ft/min)

q_i = air flow (cfm)

A_i = area of duct (square feet)

d_i = diameter of duct (inches)

a_i = width of duct (inches)

b_i = width of duct (inches)

Imperial Units Air Flow Velocity Calculator

Air velocity can be calculated with the calculator below. Add air volume - q - and diameter - d - (or length a and b).

Air volume - q_i - (cfm)

Diameter - d_i - (inches)

or alternatively

Length side - a_i - (inches)

Length side - b_i - (inches)

SI - Units

Air velocity in a duct can alternatively be expressed in SI units like

v_m = q_m / A_m = 4 q_m / (π d_m²) = q_m / (a_m b_m)         (2)

where

v_m = air velocity (m/s)

q_m = air flow (m³/s)

A_m = area of duct (m²)

d_m = diameter of duct (m)

a_m = width of duct (m)

b_m = width of duct (m)

SI Units Air Flow Velocity Calculator

Air velocity can be calculated with the calculator below. Add air volume - q - and diameter - d - (or length a and b).

Air volume - q_m - (m³/s)

Diameter - d_m - (m)

or alternatively

Length side - a_m - (m)

Length side - b_m - (m)

Sponsored Links

Related Topics

• Ventilation - Systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more

Related Documents

• Air Duct Velocity Diagram - Air flow volume, duct size, velocity and dynamic pressure
• Air Ducts Friction Loss Diagram - Major loss diagram air ducts - SI units
• Air Ducts Friction Loss Diagram - Major loss diagram air ducts - Imperial units ranging 10 - 100 000 cfm
• Air Velocities in Ducts - Recommended maximum air velocities in ventilation ducts
• Air-Duct Sizing - Air flow and required duct area
• Circular Duct Sizes - Dimensions of circular ventilation air ducts
• Colebrook Equation - Calculate friction loss coefficients in pipes, tubes and ducts
• Converting Round Duct Diameter to Area - Converting round duct areas to square feet and square meters
• Ductwork Sheet Metal Gauges - Sheet metal gauges used in ductwork
• Equal Friction Method - The equal friction method of sizing ducts is easy and straightforward to use
• Exhaust Outlets - Capture Air Velocities - Capture air velocities in front of exhaust outlets - online exhaust outlet velocity calculator
• Friction Loss in Ducts - Friction loss or major loss in ducts - equations and online calculator for rectangular and circular ducts - imperial units
• Hydraulic Diameter - Hydraulic diameter of ducts and tubes
• Recommended Air Velocities in Ducts - Ducts and recommended air velocities
• Sizing Circular Ducts - A rough guide to maximum air volume capacity of circular ducts in comfort, industrial and high speed ventilation systems
• Sizing Ducts - The ductwork of ventilation systems are often sized with either the Velocity, the Constant Pressure Loss (or Equal Friction Loss) - or the Static Pressure Recovery Methods
• Velocities in Ventilation Ducts - Recommended velocities in ventilation ducts