Acoustic Louvres

The Crossflow ALS (CALS) range is a fabricated acoustic louvre designed for commercial projects where reduction in sound transmission is required whilst maintaining weathered ventilation. The CALS louvre is suitable for all applications and can be both vertically and horizontally mounted into pre-formed structural opes. The modular units can be manufactured to suit specific dimensions on site. Each louvre blade is filled with a sound absorption mineral wool to achieve the required acoustic performance. They are quick to install with all fixings being grade A4 stainless steel and are virtually maintenance free.

Acoustic Louvres

MATERIALS

  • Outer frame casing manufactured from 18 gauge galvanised steel.
  • Louvre blades manufactured from 22 gauge galvanised steel.
  • Acoustic medium-tissue faced 45kg/m3. Non toxic, vermin and moisture proof mineral wool (packed to +10% compression to eliminate voids).
  • Perforated galvanised sheet to rear of blades.
  • Metal or aluminium bird mesh as standard.

Acoustic Louvres

LOUVRE OPTIONS

  • Perimeter flashings to suit application.
  • HDPE insect screen.
  • Blanking Plate as required.
  • Flanged or glazing outer frame.
  • Available in galvanised steel, 2mm aluminium, polyester powder coat finish to any RAL colour, and stainless steel.

Acoustic Louvres

Crossflow Acoustic Louvres - Sound Transmission

Model Louvre Depth (mm) 63 125 250 500 1K 2K 4K 8K
CALS 100 100 5 4 5 6 9 13 14 13
CALS 150 150 6 6 8 10 14 18 16 15
CALS 275 275 6 5 8 9 17 17 14 14
CALS 300 300 6 7 10 12 18 18 14 13
CALS 300 C 300 6 6 8 13 18 20 16 17
CALS 600 C 550 7 9 12 24 31 33 29 30

crossflow-acoustic-louvre3

How to specify Crossflow CALS Louvres

Supply and install CALS louvres as manufactured by Crossflow Ltd. Outer frame casing shall be made from 18 gauge (1.2mm) galvanised steel. Louvre blades shall be made from 22 gauge (0.7mm) galvanised steel. Louvre blades to be filled with acoustic medium-tissue faced, non-toxic, vermin and moisture proof mineral wool to achieve the required acoustic performance as indicated.

  • Static pressure drop of the louvres not to exceed ______
  • Pa at a face velocity of _____ m/sec
  • Louvre to have galvanised bird mesh fitted to the rear as standard.
  • Louvre finish to be_____ in RAL colour _____

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CALS 100 - Standard Acoustic Louvre

CALS – 100 ACOUSTIC PERFORMANCE
Octave band Centre frequency (Hz) 63 125 250 500 1000 2000 4000 8000
Transmission Loss (dB) 5 4 5 6 9 13 14 13

 

CALS – 100 AERODYNAMIC PERFORMANCE
Static Pressure Drop (N/m2) 10 20 30 40 50 60 70 80 90 100
Face Velocity (m/s) 0.92 1.30 1.59 1.84 2.05 2.25 2.43 2.61 2.76 2.90
Nominal Free Area (%) 42%

CALS 150 - Standard Acoustic Louvre

CALS – 150 ACOUSTIC PERFORMANCE
Octave band Centre frequency (Hz) 63 125 250 500 1000 2000 4000 8000
Transmission Loss (dB) 6 6 8 10 14 18 16 15

 

CALS – 150 AERODYNAMIC PERFORMANCE
Static Pressure Drop (N/m2) 10 20 30 40 50 60 70 80 90 100
Face Velocity (m/s) 0.53 0.73 0.90 1.04 1.16 1.28 1.37 1.47 1.56 1.64
Nominal Free Area (%) 32%

CALS 275 - Standard Acoustic Louvre

CALS – 275 ACOUSTIC PERFORMANCE
Octave band Centre frequency (Hz) 63 125 250 500 1000 2000 4000 8000
Transmission Loss (dB) 6 5 8 9 17 17 14 14

 

CALS – 275 AERODYNAMIC PERFORMANCE
Static Pressure Drop (N/m2) 10 20 30 40 50 60 70 80 90 100
Face Velocity (m/s) 0.90 1.15 1.48 1.79 2.05 2.15 2.40 2.60 2.77 2.84
Nominal Free Area (%) 42%

CALS 300 - Standard Acoustic Louvre

CALS – 300 ACOUSTIC PERFORMANCE
Octave band Centre frequency (Hz) 63 125 250 500 1000 2000 4000 8000
Transmission Loss (dB) 6 7 10 12 18 18 14 13

 

CALS – 300 AERODYNAMIC PERFORMANCE
Static Pressure Drop (N/m2) 10 20 30 40 50 60 70 80 90 100
Face Velocity (m/s) 0.94 1.31 1.61 1.83 2.13 2.27 2.46 2.63 2.84 2.99
Nominal Free Area (%) 45%

CALS 300 - Chevron Acoustic Louvre

CALS – 300 ACOUSTIC PERFORMANCE
Octave band Centre frequency (Hz) 63 125 250 500 1000 2000 4000 8000
Transmission Loss (dB) 6 6 8 13 18 20 16 17

 

CALS – 300 AERODYNAMIC PERFORMANCE
Static Pressure Drop (N/m2) 10 20 30 40 50 60 70 80 90 100
Face Velocity (m/s) 0.91 1.26 1.49 1.70 2.01 2.08 2.25 2.31 2.60 2.70
Nominal Free Area (%) 45%

CALS 600 - Chevron Acoustic Louvre

CALS – 600 ACOUSTIC PERFORMANCE
Octave band Centre frequency (Hz) 63 125 250 500 1000 2000 4000 8000
Transmission Loss (dB) 7 9 12 24 31 33 29 30

 

CALS – 600 AERODYNAMIC PERFORMANCE
Static Pressure Drop (N/m2) 10 20 30 40 50 60 70 80 90 100
Face Velocity (m/s) 0.68 0.94 1.15 1.30 1.47 1.61 1.77 1.89 2.02 2.13
Nominal Free Area (%) 45%