During inspection, found the evaporator coil heavily rusted with a leak. In addition found the outside unit significantly low on refrigerant charge (410A), and the contactor is worn. The plenums and distribution boxes are made of fiberglass ductboard, and both the supply and return plenums have begun to show signs of fiberglass shedding. The supply plenum specifically has set up bio growth. No flood protection in the overflow pan, and the furnace blower wheel is heavily impacted with debris. Recommending replacing the system along with all fiberglass duct-board plenums and distribution boxes. System: Lennox, 2007 heat-cool & furnace. Dual zone upstairs and main floor.