Seal-tite 92RFB-172220 Return Air Support Box

Product Description

The SEAL-TITE 92RFB-172220 is a furnace return air support box designed to provide structural support and a sealed plenum connection at the return air inlet of a residential forced-air furnace. It measures 17-7/8 inches by 22-3/16 inches by 20 inches, making it sized for a specific duct opening common in residential installations. This component creates a stable, air-tight transition between the return ductwork and the furnace cabinet, reducing air leakage at one of the most common infiltration points in a forced-air system. HVAC technicians and installers use this box during new furnace installations or when retrofitting an existing return air configuration.

This return air support box is suited for residential gas or electric forced-air furnace installations where the return air duct connects at the base or side of the furnace cabinet. It is typically installed in conjunction with a filter rack, plenum, or duct board assembly. The 17-7/8 by 22-3/16 inch face opening and 20-inch depth allow it to fit into framed or unframed mechanical closet openings and crawl space installations where return air must be channeled cleanly into the unit.

Key Features

• Sized at 17-7/8 x 22-3/16 x 20 inches for a specific return air duct rough opening
• Provides structural support at the furnace return air inlet to reduce cabinet flex and air leakage
• Designed for use in residential forced-air furnace applications
• Supports integration with filter racks, plenum boards, and duct assemblies at the return side

Compatibility

Designed as an OEM-style replacement and new-installation return air support box for residential forced-air furnace systems requiring a 17-7/8 x 22-3/16 inch return air opening with a 20-inch box depth.

Installation Notes

Installation is typically performed by a licensed HVAC technician or qualified installer. Power to the furnace and any associated air handling equipment should be shut off at the disconnect before beginning work on the return air section of the system. The support box should be secured per local mechanical code requirements, and all seams should be sealed with mastic or UL-listed foil tape to meet ACCA and energy code air-sealing standards. Do not use standard duct tape as a permanent sealant on return air joints.

Technical Specifications

• Width: 17-7/8 inches
• Depth (Face): 22-3/16 inches
• Height: 20 inches

Standard Information

• Brand: SEAL-TITE
• Manufacturer Part Number: 92RFB-172220