The one we had, utilized a insulated rectangular duct( about 8”x10”x 6’ dimension) that ran directly from the furnace to a central room in our house( we had the furnace raised up so the duct would go right in a window opening of our house).

it was as simple and CHEAP of a installation one could do.  I think the one I have pictured is more meant to be plumbed into the air return or plenum on a existing house furnace to distribute the heat more evenly.