Duct Covering : A material such as adhesive, insulation, banding, coating(s), film, and jackets used to cover the outside surface of a duct, fan casing, or duct plenum
NFPA 90B Standard for the Installation of Warm Air Heating and Air-Conditioning Systems, 2009 ed. (Std: Instll of Warm Air Heating and AC Sys - Amer) {236 NFC}