Ducting Silencers

30 products

Duct silencers, also called duct attenuators, fit inline in ventilation ductwork to cut the fan and airflow noise carried along the duct to occupied rooms. We stock Systemair LDC circular silencers for spiral ducting from 100mm to 500mm diameter in lengths from 300mm to 1200mm, and Systemair LDR rectangular silencers from 300 x 150mm to 1000 x 500mm, 950mm long with a universal flange for PG or Metu profile connections. Use the buttons below to filter by duct type, or for help choosing the right silencer, email hello@efans.co.uk or call 0161 399 3825.

Frequently asked questions

What is a duct silencer?

A duct silencer is a section of ductwork lined with sound absorbing insulation. Air passes straight through while the lining absorbs noise from the fan and the airflow, so less noise reaches the rooms the duct serves.

Circular or rectangular?

Match the silencer to your ductwork. LDC circular silencers connect straight into round spiral ducting. LDR rectangular silencers are for rectangular duct runs and fit directly before or after Systemair KE, KT, RS and RSI rectangular duct fans.

Which length do I need?

A longer silencer gives more noise reduction. The LDC range comes in 300mm, 600mm, 900mm and 1200mm lengths depending on diameter. Where a large reduction is needed, two silencers can be fitted in series. The datasheet on each product page shows the noise reduction at each frequency.

Where should a duct silencer be fitted?

For the best result, fit it immediately after the fan or after a bend, so noise is absorbed before it travels along the duct. On supply and extract systems, fit one on each side of the fan if both runs serve occupied rooms.

Will a silencer reduce airflow?

A silencer adds some resistance to the system, so allow for it when sizing the fan. The pressure drop at different airflows is shown on each product datasheet.

Do you supply silencers for projects?

Yes. We supply M&E contractors, ventilation installers and facilities teams. Send us the duct sizes or a schedule and we will quote: email hello@efans.co.uk or call 0161 399 3825.

Circular Rectangular