It's fall here in the DC area, which generally means warm, dry days and cool nights. The last time we turned our a/c on was on September 6th, when we had 60 people over for a potluck bbq. Our windows are always open unless we know it's supposed to rain- hooray for no hvac electricity costs!
Anyway, we take our kids out for a walk in the evenings, and without fail, every single neighbor has their house shut up tight. I understand if some have allergies (fall is also ragweed season), but you can't tell me that every single neighbor suffers. I don't get it. Why not let the fresh air in and let mother nature take care of your heating/cooling needs?