Sonodec 254 mm 3 meter

Acoustically insulated ducting from DEC International in 254 mm, three metres long, for systems with a 250 mm connection.

Two limits that sit lower than on plain ducting

Insulated ducting is not a thicker version of plain ducting, and on two points you may ask less of it. At this size you notice that soonest.

The bend radius. DEC gives a minimum of 0.54 times the diameter plus 25 mm. For 254 mm that works out at roughly 16 cm measured from the centre of the bend. Bend it tighter and the inner hose closes up while the wool on the inside of the curve is crushed flat, where it loses its damping effect. So plan for a generous sweep rather than a right-angled turn.

The working pressure. Maximum 2500 Pa, against 3000 Pa for plain Combiconnect. That is still far more than a grow set-up builds, but the direction is what counts: a perforated inner hose takes less pressure than a solid one.

Otherwise the same values apply as across the range: -30 to 140 °C and a maximum air speed of 30 metres per second.

For orientation, the measured attenuation for this diameter over three metres: 32 dB at 125 Hz, 36 at 250, 32 at 500, 37 at 1000, 34 at 2000 and 27 at 4000 Hz.

Technical Specifications:

• Type: Sonodec acoustically insulated ducting
• Interior: perforated aluminium laminate inner hose with barrier
• Insulation blanket: 25 mm glass wool, 16 kg per m³
• Minimum bend radius: 0.54 times the diameter plus 25 mm
• Maximum working pressure: 2500 Pa
• Bore: 254 mm
• Length: 3 metres

Frequently asked questions

What happens if I bend it tighter anyway?
The inner hose pinches shut and the wool is crushed. You lose airflow and damping at once.

How do I make a right-angled turn?
With a 250 mm steel bend in the run, and the acoustic ducting on the straight sections either side.

Is 2500 Pa enough for my set-up?
Almost certainly. A filter and a long duct together usually stay well below it.