I'm always kind of surprised that literally every house in NorCal doesn't have a whole house fan. To people who have never heard of them: they suck the hot air out of your house into the attic, and cool outside air in to replace it. Cool the whole house for pennies! No refrigerants or environmentally messy stuff! Dirt cheap installation you can probably do yourself! It's the absolutely perfect way to cheaply and greenly cool a house in temperate climates. And yet, no one here has them.