Flexduct 620C Flex Air Duct 6 in X 25 Ft R-4.2 Fiberglass

Product Description

The FLEXDUCT 620C is a UV-inhibited fiberglass flexible air duct rated at R-4.2, supplied in a 6-inch diameter by 25-foot length. It is designed for use in residential and light commercial HVAC distribution systems where flexible duct runs connect rigid trunk lines to supply registers or diffusers. The fiberglass construction provides thermal insulation at R-4.2 to reduce heat gain and loss across the duct run. The UV-inhibited outer jacket resists degradation in installations exposed to incidental light, making it suitable for attic and crawlspace environments. Licensed HVAC technicians and sheet metal installers are the typical trade for this product.

This flex duct is used in forced-air heating and cooling systems to route conditioned air from main trunk lines or air handlers to individual supply outlets. It is well suited for attic drops, short branch runs, and tight-access spaces where rigid duct is impractical. The 25-foot coil length allows a single section to serve multiple short branch runs or one longer residential drop without splicing. It is appropriate for residential new construction, HVAC system retrofits, and equipment changeouts requiring new or extended duct distribution.

Key Features

• R-4.2 fiberglass insulation reduces heat transfer along the duct run
• UV-inhibited outer jacket rated for attic and crawlspace exposure
• 6-inch diameter fits standard residential branch-run collar sizes
• 25-foot length minimizes splice points on longer branch runs
• Flexible construction allows routing around framing and obstructions without rigid fittings

Compatibility

Designed as an OEM-style replacement and new-installation flex duct for residential forced-air HVAC systems using 6-inch branch-run connections.

Installation Notes

Installation should be performed by a licensed HVAC technician in accordance with ACCA Manual D duct design guidelines and local mechanical code requirements. Power down the air handler or furnace and close the zone dampers before connecting or disconnecting flex duct sections. Secure each end with an approved clamp and mastic or UL 181-listed tape — never use standard cloth duct tape. Avoid sharp bends and excessive compression of the inner liner, as both conditions significantly reduce airflow and system efficiency.

Technical Specifications

• Diameter: 6 inches
• Length: 25 feet
• Insulation R-Value: R-4.2
• Insulation Material: Fiberglass
• Jacket Type: UV-Inhibited
• Jacket Color: Black

Standard Information

• Brand: FLEXDUCT
• Manufacturer Part Number: 620C