ARSD 44:70:10:23. Ducts

Each duct must be constructed of iron, steel, aluminum, or other approved metal or materials as defined in NFPA 101 Life Safety Code, 2012 edition, § 32.3.6.2.1. Duct linings, coverings, vapor barriers, and the adhesives used for applying them must have a flame spread index of not more than twenty-five and a smoke emission rating of not more than fifty using ASTM E84-23D, 2010 edition, Standard Test Method for Surface Burning Characteristics of Building Materials. Each cold air duct must be insulated wherever necessary to maintain the efficiency of the system or to minimize condensation problems.