มิถุนายน 23, 2022
มิถุนายน 23, 2022



Combinations of external weather louvres and non-return dampers as a protection against the direct ingress of rain, leaves and birds, and to prevent air from flowing against the intended airflow direction.

  • Maximum width of 2000 mm, maximum height of 1665 mm
  • Low differential pressure due to aerofoil blades
  • Low air-regenerated noise
  • All aerodynamic data is measured in aerodynamics and acoustics laboratories
  • Maximum differential pressure: 100 Pa
  • Available in standard sizes and many intermediate sizes
  • Pre-assembled combination, hence fast and easy to install

Optional equipment and accessories

  • Installation subframe
  • Insect screen
  • Powder-coated or anodised surface
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  • Combinations of Type WG external weather louvres and Type KUL non-return dampers for protecting fresh air and exhaust air openings in air conditioning systems
  • Protection against the direct ingress of rain as well as against leaves and birds
  • Recommended face velocity for fresh air openings: 2 – 2.5 m/s max.
  • Prevention of unwanted airflows against the intended airflow direction when the system is not in operation
  • Blades close automatically when the system is shut down

Special characteristics

  • Any intermediate sizes within the standard size range are available
  • Low installation effort on site since external weather louvre and non-return damper are factory combined and assembled
  • Operating temperature 20 – 80 °C
  • For very large sizes, several combinations can be arranged side by side or on top of each other
  • Maximum pressure of 100 Pa
  • Low differential pressure due to aerofoil blades
  • Non-return dampers are opened and closed by the airflow; no actuator is required

Nominal sizes

  • B: 200 – 1600 mm, in increments of 1 mm
  • H: 180, 345, 510, 675, 840, 1005, 1170, 1335, 1500, 1665 mm (intermediate sizes 183 – 1664 in increments of 1 mm)
  • Any combination of B × H




  • WG-KUL: External weather louvre made of galvanised sheet steel, with non-return damper
  • WG-AL-KUL: External weather louvre made of aluminium, with non-return damper
  • 1: Fresh air opening
  • 2: Exhaust air opening

Parts and characteristics

  • Border
  • Regular blades and bottom blade
  • Wire mesh
  • Optional insect screen
  • Visible mullion or stabilising mullion at the rear, from B = 1385 mm
  • Casing of non-return damper
  • Blades with low-friction bearings
  • Blade restrictors
  • Blade tip seals
  • Bottom travel stop (angle section)
  • Visible mullion at the rear from B = 1000 mm


  • Installation subframe: Installation subframe for the fast and simple installation of external weather louvres

Construction features

External weather louvre

    • Free area of approx. 60 %, with insect screen approx. 45 %
    • Wire mesh at the rear, mesh aperture 20 × 20 × 1.8 mm
    • Optional insect screen at the rear, mesh aperture 1.25 × 1.25 × 0.4 mm
    • Border fixing holes

Non-return damper

    • Casing, material thickness 1.25 mm
    • Blades, material thickness 1 mm
    • Flanges on both sides, suitable for duct connection, with corner holes
    • Additional side bar with fixing holes to accommodate the blade shafts and integral blade restrictors (pins)
    • Blade restrictors prevent the blades from opening beyond a certain angle

Materials and surfaces

  • Border, mullion and blades made of formed galvanised sheet steel or aluminium
  • Wire mesh made of galvanised steel or stainless steel
  • Casing and travel stop of the non-return damper made of galvanised sheet steel
  • Blades made of formed aluminium
  • Mullion (from B = 1000 mm) made of galvanised sheet steel
  • Blade shafts made of brass
  • Side bar made of PVC plastic
  • Blade tip seals made of foamed polyester
  • Blade restrictors made of plastic
  • P1: Powder-coated, RAL CLASSIC colour
  • PS: Powder-coated, NCS or DB colour


  • Maintenance-free as construction and materials are not subject to wear
  • Contamination should be removed as it may lead to corrosion and to increased closed blade air leakage


Product Information


Operation manuals