Mueller Streamline 5KMR8 Flex Duct 5 in R-8 Foil 25 Ft

Product Description

The MUELLER STREAMLINE 5KMR8 is a flexible insulated HVAC air distribution duct built for small-diameter branch runs in unconditioned spaces such as attics, crawlspaces, and mechanical rooms. It ships in a 25-foot length at 5 inches in diameter and carries an R-8 insulation rating, making it suitable for installations where minimizing heat gain or loss along the duct run is a priority. The foil outer jacket provides a durable, moisture-resistant barrier. Licensed HVAC technicians install this product as part of residential or light commercial forced-air distribution systems.

This flexible duct is used in branch-run applications connecting supply plenums or trunks to diffusers, registers, and terminal units. The 5-inch diameter suits lower-cfm branch circuits typical in bedroom, bathroom, and utility-space supply runs. The R-8 insulation value meets or exceeds energy code requirements in many jurisdictions for ducts located in unconditioned spaces, reducing the need for supplemental duct wrapping on those runs.

Key Features

• R-8 insulation rating for high thermal efficiency in unconditioned spaces
• 5-inch inner diameter sized for small-diameter branch supply runs
• Foil outer jacket resists moisture and provides a cleanable outer surface
• 25-foot length per section reduces the number of joints on longer runs
• Flexible construction allows routing around framing, joists, and obstructions without rigid fittings

Compatibility

Designed as an OEM-style flexible duct section for use in residential and light commercial forced-air HVAC systems requiring a 5-inch insulated branch duct with R-8 thermal performance.

Installation Notes

Installation should be performed by a licensed HVAC technician in accordance with SMACNA guidelines and applicable local mechanical codes. Power down the air-handling unit and close the system before making duct connections. Secure each end with an approved duct clamp and mastic or listed duct tape rated for flexible duct; standard cloth-backed tape is not acceptable under most energy codes. Avoid sharp bends or compression of the duct, as either condition reduces effective airflow and insulation performance.