Silencer selection
A silencer is chosen against four numbers: what the plant makes, what the room is allowed, how much air must pass, and how much pressure can be given up.
Also in this branch
Selection is not picking a length from a page. Attenuation varies by frequency and so does the problem — a fan that is loud low down is not fixed by a silencer that performs high up. Pressure drop matters just as much, because it becomes fan power, running cost and new noise generated inside the silencer itself.
What selection needs
| Plant sound power | By octave band, from the manufacturer or measured by us. |
|---|---|
| Room target | The background noise level the space is designed to. |
| Airflow | Volume and duct size, which give the face velocity. |
| Pressure available | The budget the silencer has to work within. |
| Space available | Length and cross-section the duct run can accommodate. |
| Regenerated noise | The silencer's own contribution at the selected velocity. |
How we work
We size attenuators as part of the acoustic design, alongside the mechanical engineer's duct layout, and verify the result with measurements in the finished room. If the numbers will not reconcile within the space available, we say so early — usually the answer is a larger duct, a lower velocity or a plant location further from the quiet rooms, and all three are cheaper before installation than after.
If the attenuation, the airflow and the pressure do not reconcile, the duct is too small. Deeper silencers will not rescue it.
Also on other people's systems
We are often asked to assess systems we did not install, where a finished room misses its noise target. The report says what is happening, which path is carrying it, and what it would take to correct — see cost and design analysis.
Tell us the room
Send dimensions and intended use. You get back an indicative acoustic treatment, a systems outline and a budget range.