Long post warning.
EVERYONE SUCKS! YES YOU!!!
Nah, just kidding
Working on grow-room 2.
The challenge is that the intake for the closet already came from that nook on the right.
I have about half the stud-space blocked off and sealed, and have the hole in the closet higher than the hole outside to prevent light.
Since I can't suck directly from the new grow room, and I don't want any connection between the two, I came up with this
I just stuffed a washable filter over the hole, and have a hinged lid so I can get in to clean it. The baffles are to prevent direct light.
I have the vent for the new room in progress - and it will have a similar baffle set-up. Just leaving a hole in the side to shove a filter in, and will probably make a rack that it fits in.
And the window which extends back into the 'nook' I just boxed out.
I need to finish the vent, make and hang a door, light-proof it, and hang lights and it will be usable. Caulking and a good coat of white paint would make it better, but that would have to wait until harvest, and may... so I am pacing myself