Seal-tite 96-172818 Return Air Support Box Top Galvanized Steel

Product Description

The SEAL-TITE 96-172818 is a return air support box top designed for residential and light commercial HVAC return air plenum assemblies. Fabricated from galvanized steel, it measures 17.75 inches wide by 28.75 inches deep by 18 inches tall and features 3.5-inch vertical hemmed edges. Those hemmed edges add structural rigidity, reduce sharp-edge hazards during handling, and help seal mating plenum sections. The galvanized finish resists corrosion in attic, crawlspace, and mechanical room environments. This component supports consistent airflow geometry and minimizes air leakage at the return plenum top, contributing to measured system static pressure performance.

This support box top is suited for new installations and replacement work on return air plenums in residential split systems and packaged units. It is sized for applications requiring a 17.75 x 28.75 x 18 inch opening and is installed by HVAC technicians during plenum fabrication or retrofit. The hemmed-edge design accommodates standard sheet metal joining methods and allows for clean, finished plenum assemblies in tight mechanical spaces.

Key Features

• Galvanized steel construction provides corrosion resistance in attic, crawlspace, and mechanical room environments
• 3.5-inch vertical hemmed edges add rigidity and reduce air leakage at plenum joints
• Hemmed edges minimize sharp-edge hazards, improving safe handling during installation
• Precision-formed dimensions ensure consistent fit and smooth internal airflow geometry
• Reinforced design reduces vibration transmission through the return plenum assembly

Compatibility

Designed as an OEM-style replacement or new-construction component for return air plenum assemblies requiring a 17.75 x 28.75 x 18 inch support box top with 3.5-inch vertical hemmed edges.

Installation Notes

Installation is performed by licensed HVAC technicians following local mechanical codes and SMACNA ductwork standards. Power down the air handling unit and close the return air damper before beginning plenum work. Standard sheet metal hand tools, aviation snips, and appropriate duct sealant or fasteners are used to secure and seal the top to the plenum assembly. Verify all seams are sealed per local energy code requirements before returning the system to service.

Technical Specifications

• Width: 17.75 inches
• Depth: 28.75 inches
• Height: 18 inches
• Hemmed Edge Depth: 3.5 inches
• Material: Galvanized Steel

Standard Information

• Brand: SEAL-TITE
• Manufacturer Part Number: 96-172818