Ther may be some confusion. My question concerns my whole house fan which is installed in our attack. it's a large fan with one large vent in the second floor cieling. It's supposed to suck in cool, outside air, or in my case cooler air from our first storty. In addition I have a swamp cooler (I live in Colorado) which is mounted to the side of the house and blows in cooled air from outside. The swamp cooler does a great job of cooling the first floor. What i need to know is how to get the whole house fan tosuck up air (which it's designed to do). When I had the house inspected the inspector turned on the ubnit and i could feel the air rushing in through an open window. I have not been able to replicate the effect. Thanks!