How is a whole-house fan sized; how do whole-house fans work with attic vents? What size whole house fan will I need?

Here is some information for sizing whole-house fans.

Whole-house fans are sized by taking the square footage of the house and multiplying it by 3 to give the needed CFM capacity of the whole-house fan. The CFM is then divided by 750 to yield the required exhaust NFA (in square feet) the whole-house fan will need. An attic balanced with sufficient exhaust vents and intake vents will generally provide enough ?exhaust NFA? for the whole-house fan because the running whole-house fan uses every vent opening inside of the attic.