Gray Flex 05-4GF-8_BAG Silver Insulated Flex Duct R8 5 Inches X 25 Feet

Product Description

The Gray Flex 05-4GF-8_BAG is a silver insulated flexible air duct rated at R8, designed for residential and light commercial HVAC installations. This duct comes in a convenient bag format measuring 5 inches in inside diameter and 25 feet in length, making it a practical choice for HVAC technicians who need a reliable, code-compliant flex duct on the job. The 4GF-8 model carries an R-value of 8.0, providing superior thermal insulation compared to standard R4 or R6 flex duct options. This level of insulation helps reduce heat gain and heat loss in unconditioned spaces such as attics, crawl spaces, and mechanical rooms, improving overall system efficiency and comfort delivery. The duct has been tested and approved in accordance with UL 181 standards, certifying it as a Class 1 air duct material. This classification confirms it meets strict requirements for flame spread and smoke development, with a maximum flame spread of 25 and a maximum smoke developed rating of 50. The outer jacket is a scrim-reinforced metalized polyester vapor barrier that resists moisture penetration and helps maintain duct integrity over time. Certification labels, foot markers, size information, and performance data are printed directly on the jacket every 24 inches, with foot markers appearing every 12 inches, making field measurement straightforward. The inner liner is an exclusive patented reinforced core that creates an airtight seal to maximize airflow efficiency and minimize leakage. The fiberglass insulation layer for the 4GF-8 model is a minimum of 2 and 5 eighths inches thick, delivering the high R8 performance HVAC professionals require in energy-conscious applications. This duct handles operating temperatures ranging from -20 degrees Fahrenheit to 250 degrees Fahrenheit and a maximum positive pressure of 10 inches water gauge, with a negative pressure rating of 3 fourths inches water gauge per UL 181. It is a dependable solution for supply air distribution in forced-air heating and cooling systems.

• UL 181 Class 1 rated flexible air duct with R8 insulation value for high-performance thermal control
• Scrim-reinforced metalized polyester vapor barrier jacket with printed certification labels and foot markers every 12 inches
• Exclusive patented reinforced airtight inner liner rated for temperatures from -20 degrees Fahrenheit to 250 degrees Fahrenheit

Product Highlights

The Gray Flex 05-4GF-8_BAG delivers R8-rated insulated flexible duct performance in a 5-inch by 25-foot format, built to UL 181 Class 1 standards for HVAC technicians who need a reliable, code-compliant air distribution solution.

Product Information

Standard Information

• Brand: GRAY FLEX
• Manufacturer Part Number: 05-4GF-8_BAG

Technical Specifications

• Flex Type: Insulated
• Inside Diameter: 5 inches
• R-Value: R8
• Insulated: Yes
• Core Material: Exclusive patented reinforced inner liner
• Maximum Pressure: 10 inches positive, 3/4 inches W.G. negative per UL 181
• Operating Temperature Range: -20 degrees Fahrenheit to 250 degrees Fahrenheit
• Fire Rating: Maximum flame spread 25, maximum smoke developed 50
• UPC: 687410304258