250-900-50 round silencer NRF (50mm insulation), ETS NORD

The ETS NORD NRF 250-900-50 round silencer offers superior noise attenuation for 250 mm ducts, with an extended 900 mm length for maximum sound absorption. The sound-absorbing material of the NRF 50 250/900 silencer is mineral wool. The perforated inner tube and outer casing are made of galvanised sheet steel. Between the inner tube and the insulation, there is a fabric layer that prevents wool particles from entering the duct system.

The NRF 50 is equipped with a factory-installed rubber gasket – leakage and pressure loss in the system are reduced, and sound insulation is improved. Complies with airtightness class D.

The NRF 250-900-50 round silencer is used for installation between air ducts. This round duct silencer offers minimal resistance to airflow and can be used to reduce noise in various ventilation systems: attenuation of small fan system noise, system regeneration noise, and noise generated by the system’s terminal block.

The 250/900 NRF 50 features quick and easy installation — it can be mounted without sealants or solvents.

This silencer is ideal for HVAC applications where low noise levels are essential. Suited for various applications, including residential buildings, offices, and restaurants where noise control and reduction are essential. For greater noise reduction, multiple silencers can be installed in series. The most effective noise reduction is achieved when the silencer is installed directly behind the fan or a duct elbow.

Technical Information:
Connection diameter (d) Ø (mm): 250
Diameter “d1” (mm): 350
Length “L” (mm): 900
Insulation thickness (mm): 50
Weight (kg): 11.7
Fire resistance class: EI15, EI60
Material: Galvanised steel sheet, mineral wool