Mueller Streamline 12KMR6 Flex Duct 12in R-6 25ft

Product Description

The MUELLER STREAMLINE 12KMR6 is a foil-jacketed flexible HVAC duct designed for air distribution in systems that require higher insulation performance. With an R-6 insulation rating and a 12-inch diameter, this flex duct limits heat gain and loss across the duct run, supporting system efficiency and consistent supply-air temperatures. The outer foil jacket provides a durable vapor barrier and resists tearing during handling and installation. At 25 feet in length, each section covers a substantial portion of a typical duct run. HVAC technicians and sheet metal contractors install this product in both new construction and retrofit applications.

This flex duct is suited for residential and light commercial air distribution systems where airflow capacity and thermal control are both priorities. The 12-inch diameter accommodates high-volume supply or return trunk runs. The R-6 insulation rating makes it appropriate for unconditioned spaces such as attics, crawlspaces, and mechanical rooms where ambient temperature differentials are significant. It is used in forced-air systems served by gas, electric, or heat pump equipment.

Key Features

• R-6 insulation rating limits heat transfer across the duct wall in unconditioned spaces
• 12-inch diameter supports high-volume airflow in larger supply or return runs
• Foil outer jacket provides vapor resistance and durability during installation and service
• 25-foot length reduces the number of joints required per duct run
• Flexible construction allows routing around obstructions without rigid fittings

Compatibility

Designed as an OEM-style flexible duct for residential and light commercial forced-air HVAC distribution systems requiring a 12-inch diameter duct with R-6 insulation and a foil vapor-barrier jacket.

Installation Notes

Licensed HVAC technicians and sheet metal contractors install flexible duct in accordance with SMACNA guidelines and local mechanical codes. Power down the air handling system before disconnecting or connecting any duct section. Secure each end with approved metal clamps and mastic or foil tape rated for duct application — never use standard cloth-backed tape. Avoid sharp bends or excessive compression of the flex duct, as either condition restricts airflow and reduces effective insulation performance.