I have a 1947 Cape Cod style home. We have many projects on our list. One being becoming more energy efficient when it comes to heating and cooling. We have some insulating, etc to do. However, I was using foil tape to seal some leaks in the duct work. I noticed that there is a significant air leak in both duct runs that go to the second story. Significant air is running back down in to the basement along the duct. The leak is somewhere in the wall above. How best to solve this issue? I think this is a significant problem in our lack of air flow upstairs.
How can I seal this in the wall? Do I have to take it all apart? Should I seal it where it leaks in to the basement?
Thanks for the help.