Industrial Noise Control - Noise Barriers/Booths/Louvers/Silencers/Curtains
Rules of thumb and things to think about:
Generally it is best to engage an acoustic consultant if you have a need for an acoustic barrier or an acoustic enclosure.
Many common mistakes, or false assumptions, are made in respect of these items which can lead to their providing virtually no noise reduction at all.
A noise barrier must at least block the line of sight between the noise source and the receiver. As long as it is wide enough this can give an insertion loss of 5dBA but it is best if it is at least 30% higher than this where it could achieve a 10dBA insertion loss.
A barrier must have enough mass so that the noise is forced over it and not through it. This would generally be in the region of 15-20kg/m².
A properly designed barrier can give an extra 1dBA for each extra metre of height over and above the line of sight.
A barrier must be placed as close to the noise source as possible.
A noise barrier may require an absorptive face depending on the noise problem.
A noise barrier is unlikely to give more than a 20dBA insertion loss.
A noise barrier needs to be wide enough. It should be 8-10 times as long as the distance between the receiver and barrier itself with the receiver position being central to the barrier length.
Enclosures should not be tight fitting, space is required around the noise source depending on its spectral content.