Air Flow Products 77F122320 Transition Boot 12x23 20 in

Product Description

The AIR FLOW PRODUCTS 77F122320 is a straight transition boot with flange designed to connect square or rectangular ductwork to round collar openings in forced-air HVAC distribution systems. The boot measures 12x23 inches at the rectangular end and features a 20-inch collar. The flanged design allows for secure, flush-mount attachment to plenums, air handlers, or duct sections. This fitting is installed by sheet metal mechanics and HVAC technicians during new construction or system retrofits where duct geometry changes require a reliable square-to-round transition.

This transition boot is suited for residential and light commercial forced-air applications where a rectangular supply or return trunk must transition to a round duct run. The 77F series straight-body design keeps the airflow path direct, minimizing turbulence and static pressure loss across the fitting. It is appropriate for supply or return-side installations depending on system layout and is typically integrated into the main trunk line or at an air handler cabinet connection.

Key Features

• Square-to-round geometry transitions a 12x23 inch rectangular opening to a 20-inch round collar
• Straight body design maintains direct airflow path for reduced static pressure drop
• Flanged construction enables flush attachment to plenums, air handlers, and duct sections
• Part of the 77F series transition boot product line
• Suitable for supply and return-side duct system applications

Compatibility

Designed as an OEM-style duct fitting for forced-air HVAC systems requiring a straight square-to-round transition from a 12x23 inch rectangular duct to a 20-inch round collar connection.

Installation Notes

Installation should be performed by a licensed HVAC technician or qualified sheet metal mechanic in accordance with applicable mechanical codes. Power down the air handling unit and verify the system is de-energized before fitting work begins. Secure the boot using appropriate sheet metal fasteners and seal all joints with UL-listed duct sealant or metal tape to maintain system integrity and prevent air leakage. Follow local mechanical code and SMACNA guidelines for duct connection and support requirements.

Technical Specifications

• Configuration: Straight Transition Boot with Flange
• Transition Type: Square to Round
• Rectangular Opening: 12x23 inches
• Collar Diameter: 20 inches
• Series: 77F

Standard Information

• Brand: AIR FLOW PRODUCTS
• Manufacturer Part Number: 77F122320