When it comes to sealing air ducts, both putty sealant and aluminum foil tape are excellent options. Despite its name, never use adhesive tape, as it simply won't hold up. No matter which sealant you choose, make sure it is of high quality and that the application area is clean. Duct tape is a popular choice for many DIY projects due to its versatility.
It is made with woven fabrics to provide 26% resistance and flexibility, and can be used almost anywhere strong adhesion is needed. However, it is not suitable for sealing HVAC ducts as it is susceptible to high temperatures and leaves a residue when removed. Aluminum putty or tape is a better choice for this job. Both duct putty and aluminum tape are suitable for sealing residential ducts, and it's up to the master or DIY contractor to decide which one they prefer. Putty can be applied generously to duct joints and leaks, providing a secure seal that won't break down over time.
If you don't want to use putty, aluminum tape is a great alternative. Adhesive tape should never be used for sealing ducts. Although it works well for many heavy-duty projects, it cannot withstand the conditions of an air conditioning system.
