Climate & Ventilation — Ducting

Ducting looks like the part you do not have to decide anything about, which is why it usually gets bought on price. There are four kinds here and they do not solve the same thing. The question is not which is cheapest, but whether you want to deal with noise, condensation or vibration where it starts.

Combiconnect is the standard

This is the ordinary flexible duct and the right choice for most setups. It runs from Ø102 to Ø254 mm and you buy it by the metre or by the box. Per metre the box works out cheaper, so anyone still expanding is better off with a box. The five metre boxes cover the middle sizes, the ten metre boxes the full range.

Sonoconnect and Sonodec damp on their own

This is why the page is not only about price. Both are an inner duct inside an insulating jacket, so the duct absorbs the sound travelling through it instead of passing it to the room. Sonoconnect is sold by the metre or by the box, in the common sizes. Sonodec comes in fixed lengths of three and six metres. If your extraction exits near a bedroom, acoustic duct over the last stretch often does more than another silencer.

The rubber sleeve is not ducting

The Secret Jardin Rubber Duct is a short sleeve in Ø100, Ø125, Ø150 to 160 and Ø250 mm, meant to separate the fan from the rest of the run. Motor vibration otherwise travels along the duct into your tent frame, and the frame radiates it into the room. No silencer removes that, because it travels through the structure rather than the air.

Insulated against condensation

The Airsock is an insulated duct, Ø160 mm in five metres. Insulation earns its keep the moment you run warm, humid air through a cold room or loft: without it the moisture condenses on the outside and drips onto your floor.

Do not forget the clamps

A duct joint is only airtight once it has been pulled tight. The two worm clamps together cover 60 to 270 mm, the whole range on this page. Reducers, flanges and bends sit under Ventilation Parts.

Frequently asked questions

By the metre or by the box?
Per metre a box is cheaper, so it is the right call as soon as you need several runs. If you need exactly one length, buy by the metre.

Can acoustic duct replace a silencer?
Often partly, sometimes entirely. Insulated duct damps along its whole length rather than at one point, so it works well over a long run. If the noise is in the fan itself, a silencer remains the better answer.

Which diameter do I take?
The same as your fan and your filter, along the whole run. Every reducer costs pressure, so only step down where there is no alternative.