MRCOOL Universal 2-3 Ton Air Return Plenum Box

This is a detailed set of plans to fabricate a sheet metal return plenum specific to the MRCOOL Universal 2-3 Ton indoor unit (air handler). The box accommodates a standard sized 20”x20”x4” filter. This plan is best handed off to a local sheet metal shop to build, unless you are experienced with fabrication and have the right specialty equipment (shear, brake, Pittsburgh seamer, spot welder). What’s Inside: Overview & general notes Parts List with Diagram Assembled Dimensions Assembly Notes Detail Part Drawings Material Thicknesses