We have always been interested in energy conservation, and also keeping our electric bill down. We have an all electric newer home, with a geothermal heat pump. We keep the heat at 68 or 69 in the winter, and when we turn the air on, it's usually around 75 or 76. We haven't turned it on yet this year, but it was 80 in the house yesterday in late afternoon. It had cooled off to 71 in the morning. We have good cross-ventilation with the windows in our house. But mostly I just LOVE to have the windows open and hear the outside sounds. I hate having to close it up in the summer for the air conditioning - but eventually we will.
Living in the Midwest, but trying pinch our pennies, we set the temp at 64 in the winter. During summer, I love to open the windows. I put a fan in the window which sucks out the warm air. If it does get too hot, we turn on our AC and set it to 78. As long as the humidity is gone from the house, 78 is just fine.
Right now we are on the evaporative cooler so we keep it 72 to 74. It is much cheaper to run and as long as the humidity is low (dew point ebelow 48 or so) it is quite comfortable. Once the temps get above 110 or dew point goes about 50 we go to the A/C. Then we keep it around 78 to 82. But we have a pool so if we are warm we just jump in for a few minutes.
The other advantage of the evap is we can leave the doors open for Cinnamon and Cierra at times as the requires either the windows be cracked or you install up draft ducts (which we have) into the attic to work properly.
We generally do March through late June or July on the evap. Then July to Sept on AC and then back to the evap.
We built our house with no air conditioning. With all the windows and doors open we normally have a beautiful amount of air flow. Add cieling fans and it is perfection. Lynn and I just hate to shut up the house and both dislike air conditioning.
In the dead of summer the house might get in the 70s and a bit humid. But, there are maybe only two or three evenings a summer where it really feels sticky.
Winter 64-66 when I'm home, 60-62 when I'm not. Summer, I try and keep things open as long as possible but when the hot and humid days come. I put an AC on to 76F mostly to get rid of the humidity and keep it comfy for the dogs.