I have included a graphic below about HVAC temps. Some people think they save money by moving the thermostat up and down constantly. Did you know that you would save money & energy by leaving your thermostat at one temperature. If you raise your thermostat to 80 when you leave in the morning and then bring it back down to you 71 when you come home you spend a lot more energy than you would have by just leaving at 71 all day. When you bring the temperature up to 80 everything in the house gets warmer, the walls, furnishings, carpets, floors etc. When you bring the temperature down to 71 it could take hours to cool everything back down to that 71 degrees causing undo work on your system & energy costs. If you move the temps up and down constantly you should experiment by leaving it at one temperature and see how much it changes the power bill.
