Quietflex 8KM Flexible Duct 8 Inch R-4.2 Foil Jacket 25 Ft

Product Description

The QUIETFLEX 8KM is an 8-inch diameter flexible duct designed for residential and light commercial HVAC systems. It ships in a 25-foot length and carries an R-4.2 insulation value, providing reliable thermal performance that limits energy loss and helps maintain consistent supply air temperatures. The outer jacket is constructed from durable foil material that resists tearing and moisture intrusion. The flexible inner core promotes smooth, unrestricted airflow and operates quietly under normal system static pressures. Licensed HVAC technicians and sheet metal installers use this product for both supply and return air distribution runs.

This flexible duct suits a wide range of residential and light commercial duct distribution applications. It is commonly routed through attic spaces, crawlspaces, and mechanical rooms where rigid duct runs are impractical. The 25-foot roll length is well suited for branch runs off a main trunk or plenum. Both supply and return air configurations are supported, making this duct a versatile choice for new installations and retrofit work across a broad range of forced-air heating and cooling systems.

Key Features

• 8-inch inside diameter supports standard residential and light commercial airflow requirements
• R-4.2 insulation value reduces thermal loss along distribution runs
• Foil outer jacket resists tearing, puncture, and moisture intrusion
• Flexible inner core allows routing around obstacles without restricting airflow
• 25-foot length suits branch duct runs from trunk or plenum
• Compatible with both supply and return air applications

Compatibility

Designed as an OEM-style flexible duct for residential and light commercial forced-air HVAC systems requiring an 8-inch diameter branch duct with foil jacket insulation.

Installation Notes

Installation should be performed by a qualified HVAC technician in accordance with applicable mechanical codes, including SMACNA flexible duct installation standards. Shut down and lock out the air handler before making connections to the plenum or trunk. Avoid sharp bends and excessive compression of the duct, as both conditions reduce airflow and can increase system static pressure beyond design limits. Secure all connections with approved clamps or ties and seal with UL 181-rated mastic or tape rated for flexible duct applications.

Technical Specifications

• Inside Diameter: 8 inches
• Length: 25 feet
• Insulation R-Value: R-4.2
• Jacket Material: Foil
• Application: Supply and Return Air
• System Type: Residential and Light Commercial HVAC

Standard Information

• Brand: QUIETFLEX
• Manufacturer Part Number: 8KM