A whole house fan is usually mounted near the ceenter of the house, and when operating pulls air upward into the attic. The air is then displaced out the attic end, ridge, and eave vents. When operating a whole house fan, windows in the house, with screens, are opened to permit incoming air. The width of the opening will determine the speed of the air drawn in and expelled through the attic. Also, where windows are opened - what rooms may have an efffect on what rooms are cooled.
When a whole house fan is turned on, usually by a timer switch, air in the house is drawn in through the windows, drafted through the house, and out the attic. This does two things. It removes air being heated in the living portion of the house, replacing with outside air and humidity, and upon exhaust, it removes air that is heated by the roof within the attic space. By removing the hot attic air, and replacing the warm stagnant air in the living space, the living space air is cooled. We used to have one, and we ran it at a significanylt lower cost than running an HVAC system, and it cooled so well, we did not use the HVAC for more than half what our neighbors did during the warm summer season. A sustem like this is extremely cofortable in the evenings and at night during the summer nonths even when an HVAC unit is needed during the daytime heat.