No real need here. We do get a little HOT weather, but little enough that opening all doors and windows and running fans in strategic spots to move the air does the trick -- and even when the day is stinky hot, it cools off pretty well at night.
It barely gets to 70 F here (21 C) by the shore, so no need for A.C. I've been tempted to turn on the heater during the summer quite a few times, though.
was over 110 yesterday and the humidity makes it hard to breath. No one but no one buys a house here without central heat and air unless they're totally hard core or super-duper short on cash.