... insulated air duct 1.Density : 58 ~70kg/m3 2.Oxygen Index>42 3.Thermal Conductivity 0.023W/Mk 4.Class "O" HVAC air duct ... is the new green environmental protection material, this kind of air duct heat preservation, soundinsulated, artistic, durable, clean, health, nature ... conservation, environmental protection, it will be the traditional air duct perfect renewal product. The main feature is: 1).Ultra ...