[Jake]

Grover you are asking about cost right? In that case turn it down. Read this.

http://www.ag.ndsu.edu/news/newsreleases/2008/feb-28-2008/thermostat-setbacks-do-pay-off/

According to the U.S. Department of Energy Web site http://www.eere.energy.gov, you can save about 5 percent to 15 percent per year on your heating bill by turning your thermostat back 10 to15 degrees for eight hours. That’s a savings of as much as 1 percent for each degree if the setback period is eight hours long

Being the US temps are degrees F.