One metre of 200 mm insulated acoustic ducting. A perforated aluminium inner core lets sound pass into a 26 mm wall of high-density glass wool instead of bouncing down the duct and out into the room. The manufacturer rates it at up to 50% noise reduction, and it fits AC Infinity 200 mm inline fans as readily as our own VIND fans.
The cheapest useful thing you can do about fan noise
A running inline fan makes noise in two places: the motor itself, and the air rushing down the duct behind it. Plain flexible ducting does nothing about either — thin foil and a wire helix, which passes sound along and sometimes adds a resonance of its own. At 200 mm, with the airflow a fan this size moves, that second source is not a small part of the problem.
This is built the opposite way. The inner layer is perforated aluminium foil, so sound energy goes through it rather than reflecting off it, and lands in a 26 mm layer of high-density glass wool where it turns into heat instead of noise. The outer sleeve is aluminium and polyester laminate, so the whole thing still handles like ducting and bends where you need it to.
At a metre a length you put it where it earns its keep: the first metre off the fan outlet, where the noise is loudest, or the last metre before the duct leaves the building.
This or an inline silencer?
Both work, and they are not the same job.
An inline silencer is a rigid chamber you add into the run. It treats more sound than a metre of ducting will, and it is the better answer for a grow room where noise really matters. It also costs considerably more and takes up a fixed length of space.
This ducting is $49.95 and it is also the duct — it carries the air as well as absorbing the noise, so it is not an extra component in the run, it is the run. If you are already buying ducting and would like it to be quiet, this costs you the difference rather than the whole thing.
Plenty of setups use both. The honest version: if your budget is tight or the noise is mild, start here. If the fan is loud and the space is lived in, the silencer will do more.
Specifications
| VIND 200 mm Silenced Acoustic Ducting | |
|---|---|
| Duct diameter | 200 mm (8″) |
| Length | 1 m (approx. 3.3 ft) |
| Noise reduction | Up to 50% (manufacturer rating) |
| Wall thickness | 26 mm |
| Inner duct | Perforated aluminium foil |
| Insulation layer | High-density glass wool, 20 kg/m³ |
| Outer sleeve | Aluminium and polyester laminate |
| Operating temperature | -30°C to 100°C |
| Maximum air speed | 30 m/s |
| Maximum pressure | 2500 Pa |
| Fits | AC Infinity and VIND 200 mm inline fans, and any standard 200 mm duct collar |
FAQ
Will it fit my AC Infinity Cloudline?
Yes. It is standard 200 mm ducting and clamps to a Cloudline S8 or T8 collar the same as any other duct. You do not need to be running a VIND fan to use it.
Does it restrict airflow?
Less than you would expect. The bore is full 200 mm — the insulation is on the outside of the inner duct, not inside the airway. Rated to 30 m/s and 2500 Pa, which is well beyond what a 200 mm inline fan will ever put through it. As with any flexible duct, keep the run as straight as you can and the bends gentle.
How many metres do I need?
One metre placed straight off the fan outlet does most of the work, because that is where the noise is loudest. A second metre at the discharge end helps if the duct exits somewhere you would rather not hear it. Beyond two metres you are into diminishing returns and a silencer is the better spend.
Is the 50% figure real?
It is the manufacturer's rating, measured under their conditions, and we quote it as theirs rather than ours. What you will actually notice depends on your fan, your duct run and the room. Treat it as the right order of magnitude rather than a promise, which is true of every acoustic product sold with a percentage on it.
Can I cut it to length?
Yes, but seal the cut end properly with duct tape so the glass wool stays where it belongs. If you can avoid cutting it, do — a factory end is tidier and there is nothing to work loose.
Do you do it in 150 mm?
We do, though the 150 mm version is out of stock at the moment. If that is the size you need, get in touch and we will point you at the alternatives.