Gray Flex 16-4GF-6_BAG Silver Insulated Flex Duct R6 16 Inches X 25 Feet Bag

Product Description

The Gray Flex 16-4GF-6_BAG is a silver insulated flexible air duct designed for commercial and residential HVAC installations where thermal performance and code compliance are required. This product ships as a 25-foot bag in a 16-inch inside diameter, making it a practical choice for large-trunk duct runs, air handler connections, and branch duct systems. It carries an R-6.0 insulation value, which meets or exceeds energy code requirements in most jurisdictions across the United States. HVAC contractors, sheet metal mechanics, and mechanical insulation installers rely on this type of insulated flex duct to move conditioned air efficiently from the air handler or plenum to supply registers throughout a building.

The 16-4GF-6_BAG is tested and listed in accordance with U.L. 181 and is approved for use as a Class 1 air duct material. This rating confirms that the duct meets fire and safety standards required for use in air distribution systems. The outer jacket is a scrim-reinforced metalized polyester vapor barrier. This construction resists moisture penetration, which helps prevent condensation buildup on the duct surface during cooling season operation. The jacketing is printed every 24 inches with certification label information, foot markers, size designation, and performance data. Additional foot markers appear every 12 inches to assist installers with accurate length measurement and cutting in the field.

The inner core uses Gray Flex's exclusive patented reinforced inner liner, which provides an airtight passage for conditioned air. Fiberglass insulation wraps the core to a minimum thickness of 2 inches, which is the construction used to achieve the R-6.0 thermal resistance rating on this model. The duct is rated for a maximum operating pressure of 10 inches positive and 3 quarters of an inch water gauge negative, per U.L. 181, making it compatible with standard residential and light commercial forced-air systems. The operating temperature range spans from negative 20 degrees Fahrenheit to 250 degrees Fahrenheit, supporting both heating and cooling applications year-round.

• R-6.0 insulation value meets energy code requirements for insulated flex duct in most markets
• U.L. 181 Class 1 listed with maximum flame spread of 25 and maximum smoke developed of 50
• Scrim-reinforced metalized polyester vapor barrier jacket resists moisture and condensation

Product Highlights

The Gray Flex 16-4GF-6_BAG delivers a UL 181 Class 1 rated, R-6.0 insulated flexible duct in a 16-inch diameter for large-scale air distribution work. Its patented inner liner, vapor barrier jacket, and wide operating temperature range make it a dependable choice for professional HVAC installations.

Product Information

Standard Information

• Brand: GRAY FLEX
• Manufacturer Part Number: 16-4GF-6_BAG

Technical Specifications

• Flex Type: Insulated
• Inside Diameter: 16 inches
• Length: 25 feet
• R-Value: R6
• Core Material: Exclusive Patented Inner Core
• Insulation Thickness: Minimum 2 inches
• Jacket Material: Scrim-Reinforced Metalized Polyester Vapor Barrier
• Maximum Pressure: 10 inches positive, 3/4 inches W.G. negative per U.L. 181
• Operating Temperature Range: -20F to 250F
• Fire Rating: Maximum flame spread 25, maximum smoke developed 50
• Listing: U.L. 181 Class 1 Air Duct Material
• UPC: 687410304210