D Cabinet Return Plenum – Filter Box (25x20x4)

This 25" x 20" x 4" return plenum filter box is designed for use with D-cabinet gas furnaces and D-cabinet air handlers. Constructed from durable galvanized steel, it provides a secure return air connection while accommodating a standard 25x20x4 air filter. Commonly used in residential HVAC installations, this filter box helps support proper airflow and filtration, improving system performance and indoor air quality. Ideal for new construction, equipment replacements, and retrofit applications. Features: Designed for D-cabinet gas furnaces and air handlers Accommodates standard 25x20x4 air filters Durable galvanized steel construction Supports proper return airflow and filtration Suitable for residential HVAC systems Ideal for new installations and replacement projects Item# 4067474; Part# SMPDF2520