Recommend replacing the ducts and the system since they aren’t up to code and the system
Inspected entire duck system, and inside the units, heavy smoke and fire smell throughout the duck system and inside the interiors of the unit which are lined with fiberglass The inside of the units are have a very hard time getting the smell out of them due to what the materials are inside of the furnace and evaporator coil. Provide estimates from duck cleaning, which I don’t recommend because it’s gonna be very hard to get the smell out of the materials that are involved to replace replacement completely from the HVAC equipment and the air ducts