Hart Cooley 51323 F216 Insulated Flexible Duct R6 4 Inches X 25 Feet

Product Description

The Hart Cooley 51323 is a UL-listed insulated flexible duct designed for residential HVAC installations. It belongs to the F216 family and delivers an R-6.0 insulation value to help reduce heat gain and heat loss in ductwork systems. The duct measures 4 inches in inside diameter and comes in a 25-foot length, making it a practical choice for connecting air handlers, registers, and diffusers in standard residential ducted systems. HVAC technicians and contractors rely on this type of flex duct for its ease of installation and verified performance across a range of conditions.

The outer jacket is a metalized polyester material reinforced with a fiberglass scrim. This construction resists punctures and holds up during routing through attics, crawl spaces, and wall cavities. The inner core is a double-ply black polyester liner rated for 12 inches W.C. positive pressure and 3/4 inches W.C. negative pressure, giving it the strength needed for most residential forced-air systems. The silver metalized jacket also acts as a vapor barrier, tested for permeation resistance per ASTM standards to prevent moisture from degrading insulation performance over time.

Hart Cooley tests all flexible duct products to industry standards set by ADC FD 72-R1, covering actual installation static pressure and temperature performance. The polyester core is independently tested for microbial resistance by GEI per ASTM D6329-98. The product is also GREENGUARD Listed for microbial resistance, supporting healthier indoor air quality. It arrives boxed, protecting the duct from compression or damage before installation. For HVAC professionals who need a reliable, code-compliant flex duct that performs consistently job after job, the Hart Cooley 51323 is a dependable choice built to last.

• R-6.0 insulation value reduces heat transfer in residential ductwork systems
• Metalized polyester jacket with fiberglass scrim provides durability and vapor barrier protection
• UL-listed and GREENGUARD Listed for microbial resistance, supporting code compliance and indoor air quality

Product Highlights

The Hart Cooley 51323 delivers verified R-6.0 performance in a 4-inch by 25-foot flexible duct format, built to meet residential HVAC installation demands with tested materials and UL listing.

Product Information

Standard Information

• Brand: HART COOLEY
• Manufacturer Part Number: 51323

Technical Specifications

• Type: UL Listed Insulated Flexible Duct
• Family: F216
• Series: Residential
• Inside Diameter: 4 inches
• Product Length: 25 feet
• R-Value: R-6.0
• Color: Silver
• Jacket Material: Metalized polyester reinforced with fiberglass scrim
• Core Material: Double-ply black polyester
• Positive Pressure Rating: 12 inches W.C.
• Negative Pressure Rating: 3/4 inches W.C.
• Gross Weight: 12.3 pounds
• Package Type: Boxed
• Listings: UL Listed, GREENGUARD Listed for microbial resistance