This is a very archaic version of what I was talking about..

http://boards.cannabis.com/indoor-gr...ml#post1161472

You got all that open wood in there which means you can frame in an AC and a DH so they're half inside/half outside the room. Get a double stacked piece of panda to put over the front and tuck around the side with duct tape. Easy in, easy out, 100% lightproof. A lot of that thread is just me thinking out loud, I figured out that you don't need any of the sophisiticated exhaust stuff, just an AC and a DH and some fart fans going across the lights.