This item is perfect for those looking to add a reliable plenum to their HVAC system. It is made of galvanized steel and has a rectangle shape with dimensions of 21 1/4 X 21 1/4 X 35.5. It also includes a 4-inch filter rack for easy maintenance. The plenum features updraft and downdraft installation options and is compatible with a variety of HVAC systems such as ducted evaporative coolers, packaged/rooftop furnaces, and ductless mini split air conditioners
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