To get the maximum cooling with what you are running right now, you should have the a/c intake coming in at the bottom of the tent, and the exhaust drawing the hot air out of the top of the tent. If the exhaust isn't at the top of the tent, the hot air will sit there and keep the temps high. You need to move that out. Even better yet, would be to put a 'Y' in and make two holes for the exhaust, one directly above each light. And since cold air is heavier than warm air, the a/c intake should be as low as possible, and the cool air will rise as it warms and gets sucked towards the exhaust, cooling the entire tent.