Siz - I've attached a pic that might help you understand this a little better.

The foto shows what a wall looks like inside. Notice the horizontal piece of wood between the two studs? It's called a fire block and every single column of studs has at least one. So, your walls consist, essentially, of many boxes - not many tubes as a lot of people think.

Lest you think I pulled my drywall off just to show you what it looks like inside, what I am doing here is building a vent using my wall space as the vent pipe. This wall is in the garage, the other side is in the house. When I'm ready, I'll cut open the wall on both sides, one hole low, the other high. Then I'll have a light-proof vent. If you have heard of people venting into drywall, this is what they were talking about.
PharmaCan Reviewed by PharmaCan on . Anyone ever vent to drywall? I have the roof near my exhuast vent, has anyone vented into the wall? does it end up getting back into the AC stinking the house? Rating: 5