When to Replace Old Ductwork Instead of Cleaning It

Original ductwork over 25 to 30 years old is often undersized for modern HVAC systems and likely lined with deteriorating insulation.

Some signs make the decision obvious.

• Crushed or disconnected runs in the attic
• Mold visible on duct interior
• Soft, deteriorating internal liner
• Major leaks at seams or boots

If certain rooms have never gotten enough heat or cool air, the ducts are usually the cause — not the equipment. Replacement is often the only real fix.