Venting plays a huge part in how your QuietCool whole house fan system works to its full potential. You can only bring in as much air as you can discharge out of your attic vents. We always recommend at least having 1 SQFT of net free area venting for every 750 CFM in your system.
For example, if a customer installs a QuietCool Trident Pro 4.8 they are pulling in roughly 4,740 CFM. If you divide that by 750, you get the number, 6.32. This is telling you that you would need 6.32 square feet of net free venting to properly ventilate all the air you are pulling in.
To simplify this, you can only bring in as much as you can take out. This is important because air, like water, takes the path of least resistance. The air must go somewhere, and if there is not enough venting, the air will go back down the walls.