Online HVAC Duct Sizer

Modern Duct Sizer

Calibrated to match ASHRAE chart point: 1000 CFM @ 0.10 Pf = 14.01" D / 934 FPM.

Unit System

Imperial (IP) Metric (SI)

Calculation Method

Friction Loss Velocity

Duct Shape

Round Rectangular Oval

Inputs

Airflow (CFM)

Friction Rate (in. w.g. / 100 ft)

Velocity (FPM)

Duct Height (in)

Outputs

Round Diameter (in)

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Rect. Width (in)

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Oval Major Axis (in)

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Velocity (FPM)

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Friction Rate (in. w.g. / 100 ft)

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Duct Visualization

Note: Graphic is a proportional representation, not to scale.