Since your closet is not sealed then if you have an intake fan, and an exhaust fan then you run the possibility of the odor coming out of the cracks of the doors. If you just use and exhaust fan then you would cut a small passive intake since you alread have some intake from the cracks in your doors. Since the air would constantly be flowing into the closet then you would not have to worry about the smell escaping. You would want to place the carbon filter up high in the closet then suck through it and blow out of the closet. you can also put the carbon filter out of the closet and place the exhaust fan up high into the closet. However this way you have to try to hide a carbon filter outside of your closet. My two Cents.