 In general, Energy Star recommends setting the temperature 4 degrees warmer when sleeping and 7 degrees warmer when you're away from home. Also, it can save you money to turn the temperature up while you're gone, but turning off the system could cost you more money. If you'll be gone for a week or more, turning it off is the way to go. Eight minutes now in front of the hour, here's Nicole Murray. And now, the three big things you need to know. Number one.