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 and systems that might need to be accessed. It's an A- on the rhizome scale. I'm planning a 3'6" x 3'6" x 7' enclosure lit by a 400w dual HPS/MH lighting. I'm going to construct a box and line it with mylar. Stealth is only an issue when it comes to odor and noise (hence the A-). I need to be able to entertain and have the in laws walking around in the living room directly upstairs with no odor and little noise. And naturally I'm concerned with heat from the light. So my issue is venting and scrubbing.

I've read and re-read the AWESOME Noob's Guide put together by rhizome and others. What a great place to start learning. Thanks. So I am familiar with the parameters of venting and scrubbing. I plan a vented hood that will be open to the grow room thereby venting both the light and the room.

My problem is that I only have one way to access an external vent - by tapping into my whole house vacuum exhaust which is 2" PVC piping. I was looking at a hood with a 6" exhaust but I'm now looking for a 4" exhaust hood (do they make a 2" exhaust hood? Would it work?) My thinking is that I will step down from 4" to 2" and out of the house. With a little negative air pressure I should not face any odor issues in the house. I'm not overly concerned with the back yard but don't want it to stink either. I figure that the setup will look like this:

Light hood > 4" exhaust tube > charcoal scrubber > inline fan > 4" exhaust tube >step down to 2" exhaust tube > 2" PVC > Y connector with vacuum vented outside.

Now I'm guessing that I will also need to find some kind of reverse air dam (not sure what it is called) that will go upstream of the Y connector such that the exhaust does not push back up the vacuum system for distribution throughout that house... That would definitely defeat the purpose.

Have any of the gurus here seen or heard of such a setup? Will I face issue stepping down from 4" to 2"? Does this seem feasible? If not I have to move out to a tent in the garage which will be very very limiting. rhizome would give my garage option a b- or perhaps c+...

Any advice appreciate!
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