By ceiling fan, you must mean the powered vents, not the actual "fan" that is in the living area? Yes, agree that the new flush windows aren't quite as nice for opening/air as the old style. However, if there's a wind blowing, you'd be surprised at how much air comes through that opening. Also, opening up the main door, and using the screen there helps as well. If you come back to a closed up, hot trailer, and it's cool outside, one item one tends to forget about is the range hood. It has a fan on it as well, and vents to the outside (if you remember to open the flaps
) which helps too.
Adjust fan speed as needed. Granted it will be a bit noisy!