Mueller Streamline 8KMR6 Flex Duct 8 in R-6 Foil 25 Ft

Product Description

The MUELLER STREAMLINE 8KMR6 is a flexible HVAC duct designed for branch runs and smaller trunk extensions that demand higher insulation performance. Built with R-6 insulation and a foil jacket exterior, this 8-inch diameter duct supports energy efficiency goals in both supply and return applications. At 25 feet per section, it provides enough length to handle most residential and light commercial routing scenarios without mid-run splicing. Licensed HVAC technicians and sheet metal contractors are the typical installers for this product type.

This flexible duct is suited for residential and light commercial forced-air systems where routing flexibility is required around framing, beams, or other structural elements. The 8-inch diameter makes it appropriate for larger branch runs carrying meaningful airflow volumes. The R-6 insulation value exceeds the R-4.2 minimum commonly required by energy codes in conditioned and semi-conditioned spaces such as attics and crawl spaces, making it a code-friendly choice in many jurisdictions. Supply and return plenum connections are both common installation points for this duct size.

Key Features

• R-6 insulation rating for improved thermal performance over standard R-4.2 flex duct
• Foil jacket exterior provides a durable, vapor-retarding outer layer
• 8-inch inner diameter supports high-volume branch and trunk extension runs
• 25-foot length reduces the number of connections needed in longer runs
• Flexible construction allows routing around obstructions without rigid fittings

Compatibility

Designed as an OEM-style replacement and new-installation flex duct for residential and light commercial forced-air HVAC systems requiring an 8-inch diameter flexible duct with R-6 insulation.

Installation Notes

Installation should be performed by a licensed HVAC technician following local mechanical codes and ACCA Manual D duct design guidelines. Secure both ends of the duct with approved draw bands and mastic or UL 181B-listed tape — never use standard cloth duct tape. Avoid sharp bends and compression of the duct core, as these conditions reduce effective airflow capacity. Support the duct at intervals per local code to prevent sagging.