Seal-tite 92RFB-242820 Return Air Support Box

Product Description

The SEAL-TITE 92RFB-242820 is a furnace return air support box designed to create a sealed, structurally sound return air plenum beneath a residential gas or electric furnace. It provides a solid base platform that channels return air into the unit while supporting the furnace load above. Measuring 24-3/4 inches wide by 28-3/4 inches deep by 20 inches tall, this box is sized for common upflow furnace installations where floor-level return air entry is required. HVAC technicians and installers use this component during new installations and system replacements to maintain proper airflow geometry and reduce duct leakage at the furnace base.

This return air support box is suited for residential upflow furnace applications where the return air duct connects from below the unit. It is typically installed on a concrete slab, wood subfloor, or platform framing. The box dimensions are sized to accommodate standard furnace footprints in that width and depth range, making it a practical fit for common 80,000 to 120,000 BTU/h class furnaces installed in closets, utility rooms, and mechanical spaces. The 20-inch height provides clearance suitable for filter rack integration or low-profile return duct transitions beneath the unit.

Key Features

• Provides structural support and a sealed return air base for upflow furnace installations
• Dimensions of 24-3/4 x 28-3/4 x 20 inches fit common residential furnace footprints
• 20-inch height accommodates filter racks or low-profile return duct transitions
• Reduces return air leakage at the furnace base when properly sealed
• Intended for new installations and system changeouts in residential applications

Compatibility

Designed as an OEM-style return air support box for residential upflow gas or electric furnace installations requiring a below-unit return air plenum base.

Installation Notes

Installation is typically performed by a licensed HVAC technician. Power to the furnace and air handler must be disconnected at the breaker before beginning work. The support box should be set level on the mounting surface and sealed at all seams and the furnace-to-box interface using approved duct mastic or metal foil tape to meet air sealing requirements under applicable mechanical codes. Do not operate the furnace until all connections are secured and sealed.

Technical Specifications

• Width: 24-3/4 inches
• Depth: 28-3/4 inches
• Height: 20 inches

Standard Information

• Brand: SEAL-TITE
• Manufacturer Part Number: 92RFB-242820