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Posted by: aliasgar

05/17/2005, 13:53:55

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is there any material which can resist sound but allow air to pass through!!!!!!!!!!






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Re: general
Re: general -- aliasgar Post Reply Top of thread Forum
Posted by: randykimball
Barney
05/22/2005, 20:37:11

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If you need to pass large amounts of air and block several Db of noise, muli-layers of reversed direction louvers with ample space between them is quite effective. The space between them will need to be adjusted to suit the wave lengths of the sound pollution.

For smaller amounts of air (for example pressure equalization) and several Db of noise, mineral wool enclosed in steel perf-sheet works. The idea here is to bounce the sound in different directions around in a chamber until it is trapped in the wool. This also will work as a duct shape with the air flowing on thru as long as you force the air flow to change speeds and direction a few times while passing thru an area surrounded by perf-steel walls lined with the proper density of mineral wool. The perf-steel sheet allows the noise to get into the wool and be trapped. This is standard proceedure in large airconditioning units, or around machinery. Remember to allow for a pressure drop caused by the speed and direction changes.

-randy-




The worst suggestion of your lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them.

Modified by randykimball at Sun, May 22, 2005, 23:14:47

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Re: general
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Posted by: Cragyon
Bart
05/21/2005, 22:52:41

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Some forms of open cell foam will reduce the amount of sound passing through it and allow air to flow.






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