Mueller Streamline 5KMR6 Flex Duct 5 in R-6 Foil 25 Ft

Product Description

The MUELLER STREAMLINE 5KMR6 is a flexible HVAC duct designed for branch-line air distribution in residential and light commercial duct systems. It features a foil jacket with R-6 insulation to reduce heat transfer and improve thermal efficiency in conditioned-air delivery. The 5-inch diameter is well suited for smaller branch runs where space constraints require a flexible, easy-to-route duct section. Licensed HVAC technicians and sheet metal contractors install this type of duct during new construction and retrofit projects where rigid duct systems transition to flexible branch lines serving individual diffusers or registers.

This flex duct is commonly used in residential forced-air heating and cooling systems, particularly in branch-line applications where the duct must navigate around framing, joists, or other obstructions. The 25-foot length provides enough material for multiple short branch runs or a single longer run to a remote register. The R-6 insulation value meets energy code minimums in many jurisdictions for unconditioned space duct installations, including attics and crawlspaces.

Key Features

• R-6 insulation rating reduces conductive heat loss and gain in unconditioned spaces
• 5-inch diameter fits standard branch-line fittings and boots
• Foil jacket provides a vapor-retarding outer layer suitable for attic and crawlspace installs
• 25-foot length accommodates multiple branch-line runs from a single coil
• Flexible construction allows routing around structural obstructions without rigid fittings

Compatibility

Designed as an OEM-style replacement and new-installation flex duct for residential and light commercial forced-air HVAC branch-line applications using 5-inch diameter fittings, boots, and collars.

Installation Notes

Installation should be performed by a licensed HVAC technician in accordance with SMACNA flexible duct installation guidelines and applicable local mechanical codes. Power down the air handler and shut off associated equipment before connecting or disconnecting duct sections. Avoid sharp bends that exceed the minimum bend radius, as excessive bending restricts airflow and reduces system efficiency. Secure connections at both ends with approved clamps and mastic or metal-backed tape rated for flexible duct use.