Noise-reducing outdoor air ducts made of stone wool, internally coated with black heavy-duty fibreglass fabric (type approved for fibre release) and exterior with dust cover made of cotton/viscose.
Outer diameter 167 mm, Inner diameter 102 mm.
Noise reduction independent of wall minimum 53 db.
The outdoor air duct has been tested by SP Sweden’s Technical Research Institute and all data and curves are designed and calculated according to these test values.
Supplied in lengths of 400 mm or 1200 mm.
Outdoor air duct as S duct