Sandwich panels made of an insulating component in rigid PUR / PIR foam and laminated on both sides with embossed aluminium foil. These panels are suitable for the construction of air-distribution ducts in air-conditioning and heating systems. The standard production thickness are of 20.5 mm & 30mm with a tolerance of + / - 0.5 mm. The density of the panels with a thickness of 30mm is of 48 kg/m with a tolerance of + / - 2 kg/m3 and panels with a thickness of 30mm is of 48 kg/m.