As suggested earlier, check ceiling insulation, in the winter I put that shrink wrap on the windows and it does help quite a bit. If you have a pool run a timer, mine is set for 3 hrs at 10pm and the water is great no need to run a pool pump all day. If you have air conditioning turn it on after it gets warm in the house in the morning and when it gets cool enough set it to dehumidify for the rest of the day.