Adjusting your thermostat to save energy

I find it really interesting that heat and air conditioner settings vary quite regularly among all my friends’ and family members’ houses. Some of our friends have even complained that our house is too warm in the summer. We keep the air on the main floor set at 78 degrees in the warm months, which is quite comfortable for us. We have a second A/C unit that provides air to the top floor, and over the years, I have noticed we are having to keep the thermostat set lower and lower. We used to be comfortable with it at 78 degrees as well, but then at night, we started dropping it to 77 degrees. During the really hot months, we have had to drop it at night to 75 degrees. I sometimes wonder if our second HVAC unit isn’t working properly or maybe it’s just because it’s warmer upstairs and requires more to cool it down. Some people I know keep their thermostat set on 70 or below all day long, and I need a sweater just to walk in their house! I don’t think I want to know what their utility bill is in the summer. It’s also interesting how you grow accustomed to the cooler or warmer temperatures. Your body seems to adjust. However, mine seems to adjust better to the warmer temperatures, and my husband can adapt better to the cooler thermostat settings. Generally though, he and I are on the same page, and I just grab an extra blanket when the air conditioning gets a little too chilly for me.