The answer to 'when to replace air duct sealing' is that you should replace your air duct sealing every 5-10 years, or sooner if you notice signs of deterioration. Properly sealing your air ducts is important to maintain HVAC efficiency and indoor air quality. Over time, duct sealants can dry out, crack, or become less effective, allowing air leaks that waste energy and reduce comfort.
Signs it's time to replace duct sealing include visible cracks or gaps, dusty or dirty ducts, uneven heating/cooling, and higher energy bills. Replacing duct sealing is a relatively simple and affordable maintenance task that can significantly improve your HVAC system's performance.