Do a little more research. I believe there are carbon scubbers to filter out smell of a grow room . Attics can get hot that may be a big concern. I would go hydro I think the smell isn't as strong. Also depends on the strain you are growing. Oh, yea welcome. You won't get better help anywhere else. Look in the hydro section for my name and (how's my girls doing) it is my first hydro grow. I have learned alot, it may cost a few bucks in the beginning but you will make up for it with the best you ever had. Plus it's a great hobby at least that's what I tell my wife. LOL I don't need filters as I have a shed and no one within smelling distance. I'm into week 6 of flowering my second grow of orange bud skunk and you can hardly smell it in the shed. That will change shortly and I can't wait for it to stink up the place. The first was northern lights and they didn't hardly smell till the end.