Planning your air vent silencer

The thing to keep in mind about vents is all it takes is for the pressure to be a little higher than atmospheric to cause loud noises. If this happens the sound can seriously harm people on the site. The loudest sounds will also disturb nearby residents, businesses, and wildlife. The solution is to design and install the right air vent silencer.

Two parts

The best silencers generally come in two parts. The first is an inlet diffuser. What this does is it provides back pressure and reduces the flow though the silencer. It can also provide some helpful attenuation.

The second part of the silencer is the absorptive pack. This is a component with perforated steel panels. The holes allow sound waves to filter though. Behind the panels will be some form of porous material that will absorb these waves. Typical substances people favour include glass fibre or rock wool.


Many people think the inlet diffuser is the least important part of the silencer. Truthfully, some models don’t even have one. However, this can be the wrong design choice. If you don’t include one, the absorptive pack generally needs to be larger so it can provide the attenuation. If size is an issue, it is better to include the diffuser.

To get the best level of noise reduction, you must have the right perforations in the steel panels. Most importantly they must be the correct size. In addition, it is vital you choose the most appropriate sound absorption material. It is a good idea to consider all the options here and select the right one for your needs.

On top of this, the silencer must have the right flow passage arrangement. A poor design may put obstacles in the way of the flow. This can result in even more noise. Some people look to avoid back pressure. However, if you choose it properly it can be very useful. Most importantly, it can allow you to use a smaller silencer. It can also reduce the flow velocity.

Designing your air vent silencer

At Ventx we know that working closely with clients is essential to producing the right equipment for them. We do just that, getting to know as much as we can about their needs. Then we can use our cutting edge design software to model a silencer that will tick all the right boxes.

If you are looking for an air vent silencer, we are confident we can deliver the perfect product for you. Get in touch now to learn more.