AC Infinity Pipe Silencer (6-inch)

A 150 mm duct silencer for the ducting run, lined with neoprene foam in a galvanised steel body. Reversible stainless steel flanges.

This is the most bought size, because 150 mm is the most common extraction size. The packaging claims a reduction of up to fifty percent, and that number deserves explaining before you count on it.

What fifty percent quieter means

Sound is measured in decibels, and that scale is logarithmic. So a difference in decibels does not read across as a percentage: ten decibels less sounds roughly half as loud to a person, while on the meter that is not a halving at all.

A percentage can therefore mean two things: less sound energy on the meter, or less loudness as your ear experiences it. Those two are far apart, and which one is meant is rarely stated.

What you can expect in practice is a clearly noticeable difference in the rush and flow, particularly at higher settings where air velocity is high. What you cannot expect is silence. Extraction at speed ten stays audible, silencer or not.

The biggest gain comes from combining the silencer with a lower setting. A fan with headroom running at four is already far quieter than the same fan at eight, and the silencer takes the edge off what remains.

Two more things help: keep the ducting short and taut, because slack ducting makes noise of its own, and hang the fan in straps so the frame does not resonate with it.

Build

Neoprene foam in an egg-crate profile inside, a galvanised steel body that copes with temperature swings, and stainless flanges of reversible design. The double flange construction also absorbs some of the vibration the fan sends into the line.

Technical Specifications:

• Model: AC-DSA6
• Collar: 150 mm (6 inch)
• Damping: neoprene foam, egg-crate profile
• Body: galvanised steel
• Flanges: stainless steel, reversible
• Acts on: flow noise inside the ducting

Frequently asked questions

Will this actually make my extraction silent?
Quieter yes, silent no. The difference is mostly in the rush of airflow, and it is larger the harder your fan runs.

Does a silencer cost airflow?
A little, as any extra section does. On a fan with headroom you will not notice it in practice.

Does it fit 150 mm ducting?
Yes, the collar matches your ducting and the clamps supplied with your fan fit it.