Noise attenuation due to elbows in ducts
Noise attenuation due to elbows in ducts
(OP)
Hello all,
I have been trying to find this information everywhere but without much luck. I want to know the formula for calculating the noise attenuation in a HVAC systme due to the inclusion of a duct. I am aware that for a curved elbow the attenuation is 0dB, but what about a rectangular bend? All I have found is a set of tables from ASHRAE applications 199 Chap46. I would like to know how to calculate the attenuation so that I can tailor the resulta to my own systems.
Any help appreciated.
Andrew299
I have been trying to find this information everywhere but without much luck. I want to know the formula for calculating the noise attenuation in a HVAC systme due to the inclusion of a duct. I am aware that for a curved elbow the attenuation is 0dB, but what about a rectangular bend? All I have found is a set of tables from ASHRAE applications 199 Chap46. I would like to know how to calculate the attenuation so that I can tailor the resulta to my own systems.
Any help appreciated.
Andrew299





RE: Noise attenuation due to elbows in ducts
RE: Noise attenuation due to elbows in ducts
"Explicit formulas for the calculation of regenerated noise in ducts" by Tim M Marks
The entire paper is available online. Do a google search and you should find the downloadable paper. The link is below but I find that long links tend not to work.
www.
You can also do a google search on "ashrae noise control" to find it. The search details are:
The 33 International Congress and Exposition on Noise Control ...File Format: PDF/Adobe Acrobat - View as HTML
ASHRAE: Systems and Applications Handbook. 1987; [6]. PA Holmes BSRIA 1975; [7]. SRL: Noise control in Mechanical Services . ...
RE: Noise attenuation due to elbows in ducts
Hatch that was exactly what I was looking for - have a star.
Andrew299
RE: Noise attenuation due to elbows in ducts
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