It's called a back draft damper. I can't seem to find a 4" to 2" duct reducer. Damn.
bigsby Reviewed by bigsby on . Venting Using 2" PVC? My first post here. Love this site. Tons of great info. I've spent the past couple of weeks reading and searching to pick up knowledge. I see a lot of posts here that could be answered with a simple search. I believing in doing homework before asking questions! That said, here is my case. I'm looking for a little help setting up my grow room. Here is what I've got. Basement set up. Good climate control all year round. Ready access to electric and H20. Lockable and away from all utilities Rating: 5