Thermaflex 56307000001 Flex Duct 7 in X 25 Ft R8 Insulated

Product Description

The THERMAFLEX 56307000001 is a KM R8 insulated flexible air duct designed for low-to-medium pressure HVAC distribution systems. The inner core is a smooth, airtight polyester film laminated over a heavy corrosion-resistant steel wire helix, providing structural support and consistent airflow. Surrounding the inner core is a thick fiberglass insulation blanket rated at R-8.0, which reduces heat gain and loss in unconditioned spaces. The outer vapor barrier is a bi-directional, reinforced metallized film that resists unraveling and moisture infiltration. This duct ships in a 7-inch diameter by 25-foot length and is installed by licensed HVAC technicians in residential and light commercial ducted air systems.

This flexible duct is suited for supply air distribution runs in residential and light commercial forced-air systems, including installations in attics, crawl spaces, and mechanical rooms where thermal performance and vapor barrier integrity are required. The R-8.0 insulation value meets or exceeds energy code requirements in most jurisdictions for ducts located outside conditioned building envelopes. It handles velocities up to 5,000 feet per minute and temperatures from -20 degrees F to 250 degrees F, making it appropriate for both heating and cooling applications.

Key Features

• R-8.0 fiberglass insulation blanket reduces heat transfer in unconditioned spaces
• Smooth airtight polyester inner core promotes low-resistance airflow and reduces turbulence
• Corrosion-resistant steel wire helix maintains duct shape under positive and negative pressure
• Bi-directional reinforced metallized outer vapor barrier resists unraveling and moisture infiltration
• Rated for velocities up to 5,000 FPM across low-to-medium pressure systems
• Backed by a 5-year manufacturer warranty

Compatibility

Designed as an OEM-style replacement or new-installation flexible duct for residential and light commercial forced-air HVAC systems requiring a 7-inch diameter insulated supply duct with an R-8.0 rating.

Installation Notes

Installation should be performed by a licensed HVAC technician in accordance with SMACNA flexible duct installation standards and applicable local mechanical codes. Power down the air handling unit and verify the system is depressurized before making duct connections. Avoid sharp bends, compression, or over-extension of the duct, as these conditions significantly reduce system airflow and duct performance. Secure both inner liner and outer jacket independently at each connection point using approved clamps and mastic or UL-listed tape.