Mathias Wandel on YouTube made some good videos a few years ago about maximizing airflow through a house with fans. One big finding was that rather than having a fan directly in a window or door pointing out it is actually best to have it a few meters away and directed at the opening. That allows the fan's airstream pull in and start moving much more air in the room out the opening. He used strips of paper hanging in doorways around the house and also I think took anemometer readings to get good measures of the airflow.
I think the general theory is to run the fans starting in the evening once the air temp outside is lower than inside, then close up the house in the morning to trap the cool overnight air?