I know you want as little ducting as possible, my problem is the size of the fan and filter. My closet is 5x2 and my fan is blowing out one of the 5 foot sides, and the filter is too long to fit behind the fan. I'm asking if the filter will still work okay, and if the fan will still blow okay, if I add some ducting between the filter and fan. Common sense tells me yes, but the answer isn't always so simple. I've never used or even held a carbon filter before, mine is being shipped to me now. I just want to use the duct to make a smooth, soft curve and then attach the filter running perpendicular to the fan, where there is more room.
@ Organics88 I went to the hardware store and bought my 6" ducting without paying much attention. When I got home and realized how solid it looked compared to the stuff I see on the online hydro shops, I though I had made a mistake and bought the wrong kind of ducting. Thanks for clearing that up for me.