In the long term, sealing your air ducts can be a great investment for your home. It can help your home remain energy efficient, save you money, and provide many other benefits. In many states, it is illegal to replace air ducts unless you are a properly licensed HVAC contractor. If you want to seal your ducts this way, along with basic joint sealing, this will add a lot of time to the project.
There are specialized products for air ducts, such as Aeroseal, that are designed to seal entire systems and not just some leak points. These liquids are sprayed into air ducts and solidify when they come into contact with a solid material (the air duct itself). Duct sealing, such as Aeroseal, is used to locate hard-to-find and reach gaps in the duct system and fill those gaps with polymer particles. The ducts distribute air throughout the house and are designed to be airtight to prevent any air leaks.
Obviously, larger, more difficult to access ducts will take longer to seal properly than easily accessible ducts in a small home. However, keep in mind that there are many different factors that will influence the final cost, such as the size of the house, the location, and the age of the duct system, in addition to the sealing method you choose. If you are properly qualified and have a contractor's license, you can replace air ducts as a DIY project. It is worth investing in replacing air ducts, as it can improve your home's air quality and energy efficiency.
If your home's ducts are located in an unfinished attic or basement, then they are the best candidates for sealing the ducts. In addition, a job that is not done properly can lead to air leaks, problems with air pressure, or even health hazards due to mold formation or poor insulation. Two key components of duct efficiency are their ability to move air from one location to another without interruption and their ability to minimize energy transfer with the surrounding air, meaning you don't want them to transfer heat or cold until the air reaches the room you're trying to heat or cool. The biggest disadvantage of replacing air ducts yourself is that it is a difficult and labor intensive task.
Therefore, it is important to consider all of these factors before deciding whether or not it is worth investing in replacing your air ducts.