When it comes to sealing air ducts, adhesive tape is not the best option. Putty sealant and aluminum tape are better choices for this purpose. Despite its name, duct tape should never be used for this job. When selecting an adhesive tape, you have several options, including aluminum foil, metal, cloth, and polyethylene.
It's important to pick a permanent option that will withstand strong air pressure and prolonged exposure to hot and cold temperatures. It's easy to make the mistake of using duct tape when you really need HVAC tape. In certain cases, the use of a sealant or putty can provide a stronger, more durable, and longer-lasting solution than adhesive tape. The downside is that they can be messy and difficult to use. The only approved options for heating, ventilation and air conditioning ducts should be putty or aluminum tape. Adhesive tape is not suitable for this purpose and, although it works great for a variety of heavy projects, it does not withstand the conditions of an air conditioning system.
So, even though its name might make it look like the perfect choice for the job at hand, never seal ducts with adhesive tape.