ALUAFS non-insolated and ISOAFS-ALU thermally insulated aluminium flexible air ducts are specifically produced for low and medium pressure heating, cooling, ventilation, exhaust and air conditioning systems. Airtight ALUAFS non-insulated and ISOAFS-ALU are produced from multi-layer aluminium and polyeste, strengthened with high tension hard steel spiring wire, while ISOAFS-ALU is surrounded with glass wool insulation and an aluminium vapour barrier. ALUAFS and ISOAFS-ALU have high elasticity and flexibility. They can be easily fitted to circular, oval or rectangular connectors. The fire resistance of both has been tested and certified by various international bodies. In the case of fire, no toxic or poisonous gases are released.