This Ventilation Fan Silencer is designed to reduce noise coming from the ventilation system and reduce air velocity. The silencer is made out of highly sound absorptive material.
We use several basic principles to reduce the ventilation noise:
Absorption. This principle is the same as used in race car muffler, i.e. it relies on the absorption qualities of the surrounding material without increasing back pressure ( obstructing airflow). The Ventilation Silencer ( Muffler) is made out of Producer’s Choice quilted acoustic blanket with 80% noise absorption rate.
Redirection of Air flow: In theory, this would reduce the sound by changing the direct line for the sound wave to travel from the Vent and into the Booth. By changing the direction of the air flow we disturb direct path on the sound waves and bounce them against the wall, part of it absorbs and partly reflects back somewhat canceling the upcoming waves traveling in the opposite direction.
Diffusion. The round shape of the muffler and 90 degrees turns create further diffusion of the sound waves and whatever gets through becomes a White noise.
Reduction of Air Velocity. The inlet of the muffler is 6 inches wide, the body is 10 inches wide and 24 inches long, outlet is 8 inches wide. The speed the air rushing into the Muffler through a 6-inch duct will be reduced when the air enters Wide body chamber like a stream falling into a lake.
(Detachable Ventilation Noise canceling device US Patent # 8,136,626 B1)
“Here are some pix of my acoustic muffler installed. Lots of air, VERY little noise!”