Did I just dodge an expensive bullet?

[JayhawkSD]

1. Not entirely valid

1. Run the attic fan at night, and it cools the house more rapidly and, more importantly, more thoroughly. It moves cool night air through the house and not only cools the interior but more effectively cools the structure of the house itself. Air in motion cools better than air which is not moving. That means the house stays cooler longer, without the fan, the next day because the structure itself serves as a "heat sink"

2. On days that it is warm and humid having the attic fan running will cause air to be in motion through the house and will cause it to feel significantly cooler. It is vastly less expensive than air conditioning and on many days will be sufficient to provide comfort. Humid air in motion can feel as much as ten degrees cooler than the same air which is not moving. Parameters are difficult to specify, but even fairly low humidity and quite high temperatures can be rendered quite comfortable by a whole house attic fan.

Not knowing your climate makes it difficult to say whether or not it would serve your purpose, but in San Diego it is quite adequate for all but a few days in summer.