Thermaflex 56310000002 Insulated Flex Duct 10 in 25 Ft R8

Product Description

The THERMAFLEX 56310000002 is a Flex-Vent KM Series insulated flexible air duct designed for residential and light commercial HVAC distribution systems. Built with a polyester and steel construction and a silver outer jacket, this duct delivers an R-8 insulation value to minimize heat loss and condensation along supply runs. It ships in a 25-foot length with a 10-inch diameter, suited for trunk-to-register connections where maintaining conditioned air temperature and velocity is critical. HVAC installers rely on this duct for its 5,000 FPM velocity rating and wide operating range of -20 to 250 degrees F.

This flexible duct is appropriate for supply air distribution in forced-air heating and cooling systems in residential construction and light commercial applications. The 10-inch diameter accommodates high-volume supply runs off larger plenums or duct boards. Its 10 in-WG positive and 0.5 in-WG negative pressure ratings make it compatible with standard air handler and furnace blower systems. The R-8 insulation rating meets or exceeds energy code requirements in most jurisdictions, making it a common choice for attic and unconditioned-space runs where thermal performance is required.

Key Features

• R-8 insulation value reduces heat gain and loss in unconditioned spaces
• 10-inch diameter, 25-foot length covers standard long supply runs
• 5,000 FPM velocity rating supports high-output air handler systems
• Positive pressure rating of 10 in-WG for robust system compatibility
• Operating range of -20 to 250 degrees F suits heating and cooling applications
• 0.05 perm vapor transmission rating helps control moisture migration

Compatibility

Designed as an OEM-style replacement and new-installation flexible duct for residential and light commercial forced-air HVAC supply systems requiring a 10-inch diameter, R-8 insulated duct connection.

Installation Notes

Installation should be performed by a licensed HVAC technician in accordance with ACCA Manual D and local mechanical codes. Shut down and lock out the air handling system before connecting or disconnecting duct sections. Secure both ends with approved clamps and mastic or UL 181B-listed tape — do not use standard cloth duct tape. Avoid sharp bends that exceed the duct's minimum bend radius, as they reduce airflow and can cause liner separation.