Use

Determine the insertion loss due to a flexible duct.

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User Inputs

  1. Air Quantity: This input automatically generates a default duct diameter in the circumstance where the diameter is yet to be determined, OR
  2. Duct Diameter: Alternative selection to Air Quantity
  3. Length (m)

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SoundSurfer Input

Sound Power Level (red node) from an upstream source.

Algorithm

Insertion loss is based on ASHRAE 2019 HVAC Applications Chapter 49 Noise and Vibration Control Table 25.

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Refer to the full text of ASHRAE 2019 HVAC Applications Chapter 49 Noise and Vibration Control for full description of application.

Output

Attenuation (dB) from the flexible duct applied to the input Sound Power Level, with attenuated Sound Power Level (red node) output octave bands in dB(A), dB(Z) and dB(C). Output being the sound power level at the upstream side of the flexible duct less the attenuation through the flexible duct.

Click on ‘Z’ of the Sound Power Output to see dB(A) and dB(C) weightings.

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