Whole house fans and attic fans are 2 different things. Whole house is great when you want outside air streaming through the house and out the attic. When outside conditions are optimal they are really nice…I have one and it works great for that. I installed it myself and it wasn’t particularly difficult, other than having to work in the attic. However, when temperatures are hot and the attic is super heated and radiating heat back down into the living space you can’t use the whole house fan or you pull hot outside air through the living space when you likely have the AC running. That is the case for an attic fan which can be mounted at a large vent exit and it will pull outside air from all the other vents, exhausting the super heated attic air. I think ideally you would have both. I currently do not have an attic fan but am considering adding one.