Duct silencers and sound attenuators reduce the fan and airflow noise that travels along the ductwork. This page has round silencers and flexible attenuators, from Ø100 to Ø400.
ETS NORD NRF 100-600-50 is a 600mm long round silencer with 50 mm mineral wool insulation, ideal for 100 mm ducts. Reduces ventilation noise and improves airflow efficiency.
ETS NORD NRF 100-900-50 - high-performance round silencer for 100 mm ducts with 900mm lenght. 50 mm insulation for superior noise reduction and minimal airflow resistance.
The DEC International Connectdec type Akudec-2 Ø100 is a strong, flexible and corrugated semi-flexible sound attenuator. 25 mm glass-wool insulation. For Ø100mm connection with round air ducts.
ETS NORD NRF 125-600-50 compact 600 mm round silencer with 50 mm mineral wool insulation. Fits 125 mm ducts for efficient ventilation noise control.
ETS NORD NRF 125-900-50 extra-length 900 mm mineral wool silencer with rubber seal for 125 mm ducts. 50 mm mineral wool insulation, delivers maximum sound attenuation with minimal pressure loss.
Ø125mm/1m AKUDEC-2 semi-flexible circular sound attenuator – aluminum insulated duct with 25mm acoustic barrier. Reduces HVAC noise efficiently. Temperature range -30°C to +250°C.
The NRF 50 160/600 ETS NORD round duct silencer, 600 mm in length with 50 mm sound insulation, is an essential component for ventilation systems, ensuring effective noise attenuation. Suitable for 160 mm air ducts, these innovative silencers provide excellent airflow performance and are used to reduce noise from various sources in ventilation systems, such as fans, heat recovery units, or terminal blocks.
ETS NORD NRF 160-900-50 is a 900mm long round silencer with 50 mm mineral wool insulation, ideal for 160 mm ducts. Reduces ventilation noise and improves airflow efficiency.
Ø160mm/1m AKUDEC-2 semi-flexible sound attenuator – premium aluminum insulated duct with 25mm acoustic insulation. Effectively reduces HVAC noise and vibration. Temperature range -30°C to +250°C.
The NRF 200-600-50 ETS NORD round duct silencer with rubber seal, 600 mm in length with 50 mm sound insulation, is an essential component for ventilation systems, ensuring effective noise attenuation. Suitable for 200 mm air ducts, these innovative silencers provide excellent airflow performance and are used to reduce noise from various sources in ventilation systems, such as fans, heat recovery units, or terminal blocks.
The NRF 200-900-50 ETS NORD round silencer with 50mm mineral wool insulation is a high-quality product that provides exceptional noise reduction in ventilation systems. Suitable for 200 mm air ducts, 900 mm long.
Ø200mm/1m AKUDEC-2 semi-flexible sound attenuator – premium aluminum insulated duct with 25mm acoustic barrier. Designed for efficient HVAC noise reduction and vibration control. For round air ducts.
The NRF 50 250/600 ETS NORD round duct silencer, 600 mm in length with 50 mm sound insulation, is an essential component for ventilation systems, ensuring effective noise attenuation. Suitable for 250 mm air ducts, these innovative silencers provide excellent airflow performance and are used to reduce noise from various sources in ventilation systems, such as fans, heat recovery units, or terminal blocks.
The NRF 250-900-50 ETS NORD round duct silencer with rubber seal, 900 mm in length with 50 mm sound insulation, is an essential component for ventilation systems, ensuring effective noise attenuation. Suitable for 250 mm air ducts, these innovative silencers provide excellent airflow performance and are used to reduce noise from various sources in ventilation systems, such as fans, heat recovery units, or terminal blocks.
DEC International Ø250mm/1m AKUDEC-2 semi-flexible round sound attenuator – aluminum insulated duct with 25mm acoustic lining. Reduces HVAC system noise and vibration for quiet, efficient airflow.
Ø315mm/1m AKUDEC-2 semi-flexible sound attenuator with 25mm insulation. Designed for 315mm air ducts to reduce HVAC noise and vibration efficiently.
ETS NORD NRF 400-900-50 - NRF 50 round duct silencer, 900 mm in length with 50 mm sound insulation, is an essential component for ventilation systems, ensuring effective noise attenuation. Suitable for 400 mm air ducts, these mineral wool silencers provide excellent airflow performance and are used to reduce noise from various sources in ventilation systems, such as fans, heat recovery units, or terminal blocks.
The NRF 50 315/900 ETS NORD round silencer with 50mm mineral wool insulation is a high-quality product that provides exceptional noise reduction in ventilation systems. Suitable for 315 mm air ducts, 900 mm long.
Which silencer, and where it goes
A silencer goes between the fan and the room, as close to the fan as the duct allows. Where the noise reaches rooms on both sides of the fan, one goes on each side.
| The route | The part | Length |
|---|---|---|
| Straight duct with room for a rigid part | Round silencer | 600 or 900 mm |
| Tight or bent route | Flexible sound attenuator | 1 m |
Round silencers
The casing is galvanised steel, lined with 50 mm of mineral wool behind a protective fabric, and the lining absorbs the noise as the air passes through. Sizes Ø100 to Ø250 come in 600 mm and 900 mm lengths, while Ø315 and Ø400 come in the 900 mm length.
Flexible sound attenuators
Because they bend, these fit where a rigid silencer does not. They are semi-flexible aluminium, in 1 m lengths, Ø100 to Ø315.
Fans built to run quietly are on the silent extractor fans page.
Common questions
Do duct silencers work?
Yes, on the noise that travels along the duct. A longer silencer takes out more noise. A silencer does not reduce the noise that the fan casing gives off into the room around it.
Where should a duct silencer be placed?
Place it between the fan and the room that hears the noise, close to the fan. Keep a straight piece of duct on each side of the silencer.
What is a duct silencer and how does it work?
It is a piece of duct with a sound-absorbing lining. The air passes through the middle, and the lining absorbs the noise that travels with it.
How to make ductwork quieter?
Fit a silencer close to the fan. Use acoustic ducting for the flexible parts of the run. Keep the bends wide and the duct size large enough, because fast air makes noise.
