Air Flow Products 77202020 Transition Boot 20x20 20 Inch Collar

Product Description

The AIR FLOW PRODUCTS 77202020 is a straight transition boot with flange, designed to convert a square or rectangular duct opening to a round collar connection. The unit features a 20x20 inch square inlet and a 20 inch round collar outlet. This style of fitting is a standard component in sheet metal ductwork systems used in residential and light commercial HVAC installations. Sheet metal workers and HVAC technicians install this fitting where a trunk line or plenum transitions to a round branch duct, maintaining airflow integrity through the connection point.

This boot is suited for supply or return air applications where a square-to-round transition is required at a register opening or branch takeoff. The flanged design allows for secure attachment to the duct opening or air handler plenum face, reducing air leakage at the joint. It is appropriate for new construction and retrofit installations where the existing ductwork requires a square-to-round adapter of this size.

Key Features

• Square-to-round geometry transitions a 20x20 inch duct face to a 20 inch round collar
• Straight profile maintains a compact footprint in tight plenum or ceiling cavity installations
• Integrated flange provides a positive mounting surface for secure attachment and reduced air bypass
• Designed for use in forced-air HVAC duct systems in residential and light commercial applications

Compatibility

Designed as an OEM-style sheet metal transition fitting for forced-air duct systems requiring a 20x20 inch square inlet to 20 inch round collar connection.

Installation Notes

Installation is typically performed by a licensed HVAC technician or sheet metal worker. Power down the air handling unit and verify the system is de-energized before working on the ductwork. Secure the boot to the duct opening using sheet metal screws through the flange, and seal all joints with UL-listed foil tape or mastic sealant in accordance with local mechanical codes and SMACNA standards. Do not compress or distort the collar during installation, as deformation can restrict airflow.

Technical Specifications

• Inlet Size: 20x20 inches
• Collar Diameter: 20 inches
• Configuration: Square to Round
• Style: Straight Transition with Flange

Standard Information

• Brand: AIR FLOW PRODUCTS
• Manufacturer Part Number: 77202020