6 in. x 25 ft. R4.2 #040 Flex Duct

Flexible Duct Systems 25’ Insulated UL 181 Class 1 Air Duct UPC #040 - R-Value 4.2 UPC #046 - R-Value 6.0 UPC #048 - R-Value 8.0 Description: Atco #040, 046, and 048 are UL 181, Class 1 Air Ducts and are manufactured with a black, heavy-duty polyethylene jacket which complies with the HUD requirements for outdoor mobile home or modular home installation. The UPC #040, #046, and #048's inner core is air-tight and is designed for low-to-medium operating pressures in HVAC systems. Construction: A double lamination of tough polyester which encapsulates a steel wire helix forms the air-tight inner core. The double-layer core is wrapped in various thicknesses of fiberglass insulation blankets to provide the R-Value specific to each product. The core and insulation are reinforced with scrim, and sheathed in a rugged and durable black seamless polyethylene jacket. Air-tight Inner Core - Energy efficient / No fiberglass erosion into air stream. Encapsulated Wire Helix - No unraveling when cut to length / Quick installation Smooth Inner Core - Low friction loss / Low operating cost.