Quietflex 9KMR8 R-8 Flex Duct 9 Inch 25 Foot

Product Description

The QUIETFLEX 9KMR8 is a 9-inch diameter, R-8 insulated flexible air duct designed for residential and light commercial HVAC distribution systems. The duct ships in a 25-foot length and is built around a corrosion-resistant steel wire helix inner core. The insulation layer uses Owens Corning EcoTouch formaldehyde-free fiberglass, made with 99% natural materials and high recycled content. The outer vapor barrier is a fiberglass scrim-reinforced metallized film laminate jacket that protects against moisture infiltration and supports efficient air delivery across supply and return runs. Licensed HVAC contractors and sheet metal installers are the typical trades specifying and installing this product.

The 9KMR8 suits residential forced-air heating and cooling systems as well as light commercial applications where flexible duct runs are required between rigid trunk lines and supply diffusers or grilles. It is rated for both US and Canadian installations and carries UL 181 and CUL S110 listings. Compliance with NFPA 90A and 90B standards makes it appropriate for use in systems covered by those fire and air distribution codes. The R-8 thermal value reduces heat gain and loss along duct runs, which is particularly relevant in unconditioned attic and crawl space installations.

Key Features

• R-8 insulation value for reduced thermal loss in unconditioned spaces
• UL 181 listed and CUL S110 listed for US and Canadian installations
• Complies with NFPA Standards 90A and 90B
• Corrosion-resistant steel wire helix inner core
• Outer vapor barrier: fiberglass scrim-reinforced metallized film laminate
• GreenGuard Gold Certified for indoor air quality
• Formaldehyde-free insulation; listed in the USDA BioPreferred Catalog

Compatibility

Designed as an OEM-style replacement and new-construction flex duct for residential and light commercial forced-air HVAC distribution systems requiring 9-inch diameter flexible duct with R-8 insulation.

Installation Notes

Installation should be performed by a licensed HVAC contractor or qualified sheet metal technician in accordance with SMACNA guidelines and local mechanical codes. Shut down and lock out the air handling unit before connecting or modifying any duct section. Secure each end of the flex duct with an approved metal clamp and listed mastic or UL 181B-listed tape; do not use standard cloth-backed duct tape. Avoid sharp bends or excessive compression of the duct, as these conditions reduce airflow and effective R-value.

Technical Specifications

• Diameter: 9 inches
• Length: 25 feet
• R-Value: R-8
• Package Weight: 14 pounds
• Package Exterior Dimensions (D x W x H): 14 inches x 14 inches x 20 inches
• Safety Standards: UL 181, CUL S110, NFPA 90A, NFPA 90B, California Prop 65 compliant
• Certification: GreenGuard Gold, USDA BioPreferred
• Insulation Material: Owens Corning EcoTouch formaldehyde-free fiberglass
• Vapor Barrier: Fiberglass scrim-reinforced metallized film laminate
• Inner Core: Corrosion-resistant steel wire helix

Standard Information

• Brand: QUIETFLEX
• Manufacturer Part Number: 9KMR8