 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 would cost you more money. If you'll be gone for a week or more, turning it off is usually the way to go. There are other ways to keep your house cooler, including adding window curtains, limiting heat-producing appliances, checking weather stripping on doors and windows, and installing ceiling fans to help circulate the air.