I consider “exterior” to mean one side of the wall is air conditioned/heated, and the other side is not. Therefore, an exterior wall has insulation in it. An interior wall is generally hollow.
I’d use some expanding foam if you could feel the air from the other side or see through it. You could also fill that area with silicone (which could also be used to help hold the flanged cover too.
It’s from a garage to an interior wall. I’m not sure if that would qualify as exterior or not.
I consider “exterior” to mean one side of the wall is air conditioned/heated, and the other side is not. Therefore, an exterior wall has insulation in it. An interior wall is generally hollow.
I’d use some expanding foam if you could feel the air from the other side or see through it. You could also fill that area with silicone (which could also be used to help hold the flanged cover too.