I'm still trying to figure exhaust. A. Having trouble figuring out a ducting run between lights and intake and exhaust. B. How a filter fits in the system and where. C. What set up would control odor the best. I have some other questions...but lets start with those. Some specs on the room: Room=13' x 7'6" x 10' Closet=2'10" x 6'10" x 10' (ballasts will have to go in here...no place outside room really). Window on one side that MUST be sealed (don't want to bother the neighbors with lights or odors). Door goes to main living space (I know...only substantial space in house). I have figured out the following: 975cf Minimum needed for 1 to 3 minute rule on air exchange with 5% added for lights, 20% added for filter: 438.75cfm Was looking at this fan as it is SUPPOSED to be quieter: 8" Max Fan I'm just trying to wrap my brain around some things...and anything you can offer up will help. It will most likely lead to more questions...but it will help. I've numbered the lights for ease of telling me how posters think flexible ducting should run. Thanks.