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Enter flow rate (L/s) and duct diameter (mm) to begin sizing



  1. Select the duct material from the drop-down list (most duct sizing tools are typically based on galvanised steel ducting by default)

  2. Enter the air flowrate in litres/second (can change to cubic metres/second by use of drop-down to the right of the input)

  3. Enter an internal duct size (this must be limited to a maximum aspect ratio of 5:1 for the results to be valid)

  4. The resulting velocity and pressure drop per unit length are displayed in the blue box.

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