You're right, heat rises. Picture the ceiling holding a "blanket" of hot air. If you have your ceiling fan blowing down, you force the air in the center of the room down. If you have it reversed, it pulls the cooler air in the center of the room upward, forcing the heat downward around the perimeter of the room. This helps in my case, because of the open stairwell. If the fan blows down, the air cycles differently and more heart runs up the stairs. Doesn't look like it would make a hill-o-beans worth of difference, but I've tried both ways and reverse works better.