TROX

Acoustic Louvres Type ‘NL & NLH’

WITH SOUND REDUCTION CHARACTERISTICS

Acoustic louvres as a protection of air conditioning systems against the direct ingress of rain, leaves and birds into fresh air and exhaust air openings

  • Maximum width of 1800 mm, maximum height of 2250 mm
  • Low differential pressure due to aerofoil blades
  • Low air-regenerated noise
  • All aerodynamic data is measured in aerodynamics and acoustics laboratories
  • Absorption material faced with glass fibre fabric and retained by perforated sheet metal
  • Double bank of louvre blades for demanding acoustic requirements
  • Non-active section, without acoustic function, for a uniform appearance
  • Multi-section constructions for large dimensions

Optional equipment and accessories

  • Powder-coated

Product Information

Variants

  • NL: Acoustic louvre
  • NL-H: Double bank for demanding acoustic requirements
  • NL-D: Non-active section for a uniform appearance

 

Construction

  • S: Galvanised sheet steel
  • A: Aluminium

 

Parts and characteristics

  • Casing
  • Sound absorbing blades (NL, NL-D)
  • Bird mesh (NL, NL-D)
  • Blades (NL-D)
  • Rear blanking plate (NL-D)

 

Construction features

  • Aerofoil blades, 150 mm blade pitch
  • Casing with fixing holes for wall installation
  • Absorption material faced with glass fibre fabric and retained by perforated sheet metal (NL, NL-H)
  • Bird mesh 12 × 12 × 1 mm (NL, NL-H)

 

Materials and surfaces

  • Casing and blades made of galvanised sheet steel (S) or aluminium (A)
  • Perforated sheet metal to retain absorption material is made of galvanised sheet steel (NL, NL-H)
  • Bird mesh made of galvanised steel (NL, NL-H)
  • Absorption material is mineral wool (NL, NL-H)

 

Mineral wool

  • To EN 13501, fire rating class A1, non-combustible
  • RAL quality mark RAL-GZ 388
  • Biosoluble and hence hygienically safe according to the German TRGS 905 (Technical Rules for Hazardous Substances) and EU directive 97/69/EG
  • Faced with glass fibre fabric as a protection against erosion through airflow velocities of up to 20 m/s
  • Inert to fungal and bacterial growth

 

Standards and guidelines

  • Insertion loss and sound power level of air-regenerated noise tested to ISO 7235
  • Sound reduction index determined according to EN ISO 10140-2 und EN ISO 717-1

 

Maintenance

  • Maintenance-free as construction and materials are not subject to wear