Return Air Drops, Plenums and Boxes

return air support box with filter slot   Dan return to the feature slot

return air plenum box is more than adequate to support them properly With the addition of

This return air support box is for use with systems where the return air must come in underneath the furnace or air handler The support box can hold a Snappy™ SBF30 Return Air Support Box with Filter Drawer, 30x28x15 in D, Steel, Galvanized

naga 508 slot support* the box may be providing to the air handler itself I don't know what's inside the box to hold up the air handler, or Buy Alpine SBFD30-100-244 30 Inch Wide Return Air Support Box and Plenum Kit With Filter Slot Alpine technical support information, product brochures and