Appliances can burn through energy while you are on vacation — refrigerators account for 3% of a home's total energy use. Ensure the refrigerator compartment is set between 36-40 degrees Fahrenheit (2.2-4.4 Celsius and two-thirds to three-quarters full at all times. You are going on vacation, so chances are the refrigerator won't be fully stocked; you can fill it with jugs or bottles of water. Cold items help to keep the temperature down inside the refrigerator, so you use less energy. The freezer compartment is usually set between -5 and 0 degrees Fahrenheit (-17.7 to -20 Celsius). You should be able to change this to 5 degrees Fahrenheit (-15 Celsius). You may need an appliance thermometer to help measure the internal temperatures. If you are away for a very long time, consider turning the refrigerator off completely. (Just be sure to remove all the food items first!)