AC Infinity Pipe Silencer (4-inch)

A 100 mm duct silencer for the ducting run, lined with neoprene foam in a galvanised steel body. Reversible stainless steel flanges.

A silencer does one thing very well and several things not at all. Knowing which of the two your noise is decides whether this is the right purchase.

Where it goes, and the noise it cannot fix

A silencer works on noise that travels with the air: the rush of airflow through ducting and the hum the fan pushes into the pipe. That sound is absorbed by the foam in the wall.

So it belongs in the run, between the fan and the outlet. That is the usual place, because that is where air velocity is highest. On the suction side, between filter and fan, also works and helps with noise radiating back into the tent.

What a silencer will not fix is noise travelling through the structure. A fan bolted tight to a tent pole passes its vibration into the frame, and the fabric then works as a loudspeaker. You hear that in the room while your ducting is silent. The cure is decoupling: hang the fan from the supplied straps or rope hangers instead of screwing it down hard.

Noise from the motor itself, radiating through its housing, also remains. On an EC motor at a low setting there is little of it, but it is there.

The rule of thumb: if what you hear is rushing and flow, a silencer helps. If it is a low hum through the wall, look at the mounting first.

Build

The inside is lined with neoprene foam in an egg-crate profile, which traps sound waves rather than reflecting them. The body is galvanised steel, and the flanges are stainless and reversible, so it can be fitted either way round.

Technical Specifications:

• Model: AC-DSA4
• Collar: 100 mm (4 inch)
• Damping: neoprene foam, egg-crate profile
• Body: galvanised steel
• Flanges: stainless steel, reversible
• Position: in the ducting run, usually on the outlet side

Frequently asked questions

How do I check it will fit?
Measure the straight length between your fan and the outlet before ordering. A silencer needs a straight section, and a bend immediately after it undoes part of the gain.

Can it go on the suction side?
Yes. Between filter and fan it damps the noise heading back into the tent.

Does it help with vibration through the floor?
Not directly. For that, hang the fan in straps rather than bolting it down.