Is your inline fan blowing air in the tent or out? When you say its blowing a lot of air around in the tent it makes me think that you have the airflow going the wrong way. For the passive airflow that onedrop mentioned to work the inline fan needs to be sucking the air out of the tent (out the round duct/tube) which will then the passive draw of fresh air from other available vents or openings. In other words, the open end of the inline fan inside the tent should be the vacuum that pulls air in through the vents rather than a blower that pushes air out the vents. If you already have it this way then I just misunderstood your wording, carry on.