Sound protection
to protect people and the environment
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Sound protection
experts since 1928
To protect the health of your staff, local residents and the environment, and to comply with legal requirements, your ventilation systems must not exceed the prescribed sound levels for operating noise.
If the necessary operating data produce excessive sound power, additional measures must be taken to reduce the sound transmission. To this end, HLU offers both standardised components and customer-specific bespoke solutions, calculated and manufactured based on setpoint values.
If the necessary operating data produce excessive sound power, additional measures must be taken to reduce the sound transmission. To this end, HLU offers both standardised components and customer-specific bespoke solutions, calculated and manufactured based on setpoint values.


Sound enclosures made of plastic
Application
- reduces the fan’s sound radiation
Features
- sound level reduction approx. 10 dB at 250 Hz
- available for fans of all types and series

Sound enclosures made of steel
Application
- reduces the fan’s sound radiation
Features
- sound level reduction approx. 10 dB at 250 Hz
- available for fans of all types and series

Duct silencer
RSD
Application
- for noise reduction in ventilation systems with small to medium flow rates
Features
- volume flow from 20 to 8000 m³/h
- available in 14 nominal diameters from 75 to 400 mm intake diameter

Splitter sound attenuator
Application
- for noise reduction in ventilation systems with small to large flow rates
Features
- dimensions are calculated individually based on the volume flow and desired sound reduction
Sound protection specifically for roof fans

Silencer for roof fans
Application
- for sound attenuation in direct combination with HF roof fans: HF D …15 /17 D and HF D …-16 D
Features
- available in 7 nominal diameters from 110 to 400 mm intake diameter
- larger nominal diameters possible on request