Air Flow Products 59040805 Insulated Boot Flange 4x8 5 in Collar

Product Description

The AIR FLOW PRODUCTS 59040805 is a short top insulated boot with flange, designed for use in residential and light commercial HVAC duct systems. This fitting transitions from round collar ductwork to a rectangular floor or wall register opening. The 59040805 features a 4x8 inch rectangular face and a 5 inch round collar, making it a direct-fit solution for connecting flexible or rigid round duct to a standard register box or floor boot opening. Licensed HVAC technicians and sheet metal installers use this type of fitting during new construction and retrofit duct work installations.

This boot is suited for residential forced-air HVAC systems where a short-depth floor, ceiling, or sidewall boot is required. The insulated construction helps reduce heat loss and condensation on the boot body, which is especially important in unconditioned spaces such as crawlspaces or attic cavities. The 4x8 inch face aligns with standard register grille sizes, simplifying grille selection and installation. The integrated flange provides a secure mounting surface for attaching the boot to subfloor or wall framing.

Key Features

• Short top design accommodates installations with limited plenum or floor cavity depth
• Insulated body reduces heat loss and limits condensation in unconditioned spaces
• 4x8 inch rectangular opening matches standard residential register grille dimensions
• 5 inch round collar connects to common round duct or flexible duct sizes
• Integrated flange provides a solid nailing or fastening surface for structural attachment

Compatibility

Designed as an OEM-style replacement or new-install fitting for residential forced-air HVAC duct systems requiring a short top insulated floor or wall boot with a 4x8 inch face and 5 inch round collar.

Installation Notes

Installation is typically performed by a licensed HVAC technician or qualified sheet metal installer. Power down the air handler and close the system dampers before connecting ductwork to prevent debris from entering the air stream. Seal all connections with listed duct sealant or UL 181-rated tape per local mechanical code requirements. Secure the flange to framing members using appropriate fasteners to prevent movement and air leakage at the boot joint.

Technical Specifications

• Rectangular Face Size: 4x8 inches
• Collar Diameter: 5 inches
• Boot Style: Short Top with Flange
• Insulated: Yes
• Series: 59F

Standard Information

• Brand: AIR FLOW PRODUCTS
• Manufacturer Part Number: 59040805