Quietflex 65SERIESBAG Flex Air Duct R8 18 Inch 25 Ft

Product Description

The QUIETFLEX 65SERIESBAG is a UV-inhibited fiberglass flexible air duct with an R8 insulation rating, designed for residential and light commercial HVAC distribution systems. The duct measures 18 inches in diameter and comes in a 25-foot length, making it suitable for main trunk runs and large branch runs where higher airflow capacity is required. The R8 thermal rating helps reduce heat gain and loss across long duct runs, supporting system efficiency. This product is installed by licensed HVAC technicians during new construction or retrofit duct system projects.

This flexible duct is well suited for attic installations, crawlspace routing, and mechanical room distribution in residential and light commercial buildings. The black outer jacket resists UV degradation, which is particularly useful in attic environments with incidental light exposure. The 18-inch diameter serves high-volume air handlers and large zone distribution layouts where smaller flex duct sizes would create excessive static pressure drop.

Key Features

• R8 insulation rating reduces thermal transfer across long duct runs
• 18-inch inner diameter accommodates high-volume airflow applications
• 25-foot length suitable for trunk runs and extended branch routing
• UV-inhibited outer jacket resists degradation in attic and exposed installations
• Fiberglass insulation construction provides thermal and acoustic performance

Compatibility

Designed as an OEM-style replacement and new-installation flexible duct for residential and light commercial HVAC air distribution systems requiring an 18-inch diameter R8-rated flex duct.

Installation Notes

Installation should be performed by a licensed HVAC technician in accordance with ACCA Manual D and local mechanical codes. Power down the air handler and close the system before connecting or modifying duct runs. Flex duct should be fully extended and supported at proper intervals to minimize pressure drop and avoid sagging. Secure all connections with approved clamps and mastic or metal tape per applicable code.

Technical Specifications

• Inner Diameter: 18 inches
• Length: 25 feet
• Insulation R-Value: R8
• Insulation Material: Fiberglass
• Outer Jacket: UV-Inhibited Black

Standard Information

• Brand: QUIETFLEX
• Manufacturer Part Number: 65SERIESBAG