Southwark Metal 23_28X8 Trunk Duct Collar 28x8 in Offset

Product Description

The SOUTHWARK METAL 23_28X8 is a rectangular offset starting collar designed for sheet metal trunk duct systems in forced-air HVAC installations. Fabricated from hot dip galvanized steel, this fitting provides a durable, corrosion-resistant connection point where a branch duct or boot transitions off the main trunk. The offset body pattern allows the takeoff to align with obstructions or tight framing conditions common in residential and light commercial construction. HVAC sheet metal mechanics and duct fabricators install this collar as part of a fully ducted supply or return air system built to SMACNA and ACCA standards.

This collar fits trunk duct installations where a rectangular starting fitting is required to initiate a branch run from the main supply plenum or extended trunk. The offset configuration is particularly useful in floor joist bays, dropped ceiling cavities, and platform framing where straight inline takeoffs cannot be used. The 28 x 8 inch throat size accommodates duct mains of that face dimension, making it appropriate for mid-capacity residential systems and light commercial zoned layouts requiring rectangular distribution.

Key Features

• Hot dip galvanized steel construction provides lasting corrosion resistance in attic, crawlspace, and mechanical room environments
• Offset body pattern accommodates framing obstructions and tight installation clearances
• Starting collar design allows branch duct or extended trunk to originate directly from this fitting
• Rectangular profile matches standard trunk duct face dimensions for leak-minimized connections
• Meets SMACNA and ACCA applicable standards for sheet metal duct fabrication and airflow performance

Compatibility

Designed for use with rectangular sheet metal trunk duct systems measuring 28 inches by 8 inches, following SMACNA and ACCA duct construction standards for residential and light commercial forced-air applications.

Installation Notes

Installation should be performed by a licensed HVAC technician or qualified sheet metal mechanic familiar with SMACNA duct construction guidelines. Power down the air handling unit and lock out the system before cutting into or modifying any existing trunk duct. Secure the collar with sheet metal screws and seal all seams with UL-listed duct sealant or mastic per local mechanical code requirements. Do not rely on duct tape alone as the primary sealant on pressure-side trunk connections.

Technical Specifications

• Size: 28 inches x 8 inches
• Material: Hot Dip Galvanized Steel
• Body Pattern: Offset
• Type: Starting, Rectangular
• Applicable Standards: ACCA, SMACNA

Standard Information

• Brand: SOUTHWARK METAL
• Manufacturer Part Number: 23_28X8