Lined Sheet-Metal Ducts - Sound Attenuation
Attenuation in ducts with 25 mm lining are indicated below:
Attenuation in ducts with 50 mm lining are indicated below:
- 1 in = 25.4 mm
- 1 ft = 0.3 m
- sound attenuation in unlined duct
Example - Sound Attenuation in Lined Duct
The sound attenuation in 610 x 610 mm lined duct is approximately 2.5 dB/m at frequency 250 Hz. The sound attenuation in 10 m duct can be calculated as
(10 m) (2.5 dB/m) = 25 dB
Related Topics
• Acoustics
Room acoustics and acoustic properties. decibel A, B and C calculations. Noise Rating (NR) curves. Sound transmission through walls. Calculate sound pressure, sound intensity and sound attenuation.
• Noise and Attenuation
Noise is usually defined as unwanted sound - noise, noise generation, silencers and attenuation in HVAC systems.
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