Televised ducts under slab floor. Ducts are galvanized metal and are extremely rusted with standing water in the ducts. The drain tile in the sump pit is at 11” below the floor whereas the ducts are at least 14” below floor level. New drain tile would need to be installed at a lower level to control the water in the ducts. Suggest installing a mini split heat pump system and abandoning the lower level system as an alternative.