This is my first post on this forum and I hope I’m doing things according to the rules. I have posted this question on another forum and as usual have not gotten a reply.
Here goes: After spending three long and hard days in my crawl space, I was able to replace the flex duct that was torn apart by rodents (before I move here).
While down there I noticed that what I think is called a Supply Plenum (long box where the ducts come out of) .
The furnace is located in a hall closet above. This box is not insulated at all.
Question is, should it be? And if so what is the best insulation to use and how to apply it. I think this box is making the banging nosie I hear when the furnace kicks on and the again about 3-4 minutes after the furnace kicks off.
Would appreciate any help at all.
Thanks in advance…