The answer to 'air duct sealing vs' is that air duct sealing is generally more effective and cost-efficient than air duct replacement for improving HVAC system efficiency and indoor air quality. Air duct sealing involves using mastic sealant or metal tape to close any leaks, cracks, or gaps in the ductwork, while air duct replacement involves completely removing and replacing the entire ductwork system.
Air duct sealing is typically less expensive than a full duct replacement, and it can often be done in a single day by a professional HVAC technician. It's also a less disruptive process for the homeowner. Air duct sealing can improve airflow, reduce energy costs, and enhance indoor comfort by preventing conditioned air from escaping the ductwork. In contrast, air duct replacement is a more extensive and costly project that may be necessary if the existing ductwork is severely damaged or inadequate for the home's heating and cooling needs.