How Does A Duct Silencer Work?

By Author: Kevin Richard
Total Articles: 242
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Sound can be considered like the ripples in a lake when you throw a stone into it making ripples and the ripples travel outward in every direction. If you then take that lake and squeeze in into the canal, those ripples would now be channeled to flow through the canal length.
This is what is happening when you connect the ductwork to a fan. All the sound waves from the fan are now channeled through the ductwork.
The ductwork works as a barrier preventing the sound waves from escaping, but there can be some breakout noise. Going back to our analogy, when the ripples pass through the canal still trying to protrude outward in almost every direction, some will fall on the walls or shore of the canal creating some noise. Likewise, breakout noise is the sound waves trying to escape from the duct.
This is where the duct silencer comes in. Positioning a silencer in the airstream will assist to absorb some of these sound waves. The amount of sound waves the silencer absorbs varies on acoustic media used in the silencer, ...
... the open area of the silencer, materials used and length of the silencer.
When the sound waves enter the duct silencer, the perforations in the baffle enable the sound wave to expand within the acoustic media of the baffle. The acoustic media is made of millions of air pockets. When the sound waves encroach on the air pockets, it causes the molecules to move and collide with each other dispelling energy as heat. This is what helps in sound reduction.
The more number of baffles you can put in a silencer, the more noise reduction you can accomplish, nonetheless you can also enhance the pressure drop. All fans create pressure to push the air forward. If there is an obstruction creating resistance in the air stream, it creates pressure against the fan dropping the pressure that the fan can create to push the air. There is a good balance between the pressures drops permitted by the fan and the airflow resistance created by the silencer.
At O’Neill Engineered Systems, our engineers have ample knowledge and years of real time experience. We take the guess work out of the equation, making sure our customers get the best performance from the industrial silencers. The quality of our products and attention to customer service makes O’Neill Engineered Systems the best in the business. Our business is noise measurement and reduction caused by the industry and to create a serene ambience.
In a world where noise is practically inevitable, silencing the noise is no long a luxury, but a requirement. Make a wise investment today by integrating duct silencers and a noise cancelling wall into your space, and enjoy the serenity it brings along with it.