The answer to 'best air duct sealing' is to use a professional HVAC contractor to properly seal your air ducts. Proper duct sealing can improve the efficiency of your HVAC system, reduce energy costs, and improve indoor air quality. A professional will use specialized tools and techniques to locate and seal any leaks or gaps in your ductwork, ensuring a tight, efficient system.
Duct sealing is an important maintenance task that should be done every few years to keep your HVAC system running at its best. While there are some DIY duct sealing products available, it's generally recommended to have a professional HVAC technician perform this work to ensure it's done correctly and safely.