The answer to 'best air duct sealing' is to use professional air duct sealing services. Properly sealing air ducts can improve the efficiency of your HVAC system, reduce energy costs, and improve indoor air quality. Professional technicians will use specialized tools and sealants to identify and seal any leaks or gaps in your ductwork, ensuring a tight, airtight system.
Sealing air ducts yourself can be challenging and may not be as effective as professional services. Improper sealing can lead to further issues, so it's generally recommended to have a qualified HVAC technician handle this task.