Manual and partial automatic defrost refrigerators and freezers should be defrosted at least twice a year. Don't put hot foods and left over meals directly into the refrigerator or freezer. Allow them to cool to room temperature first. Cover Foods and Liquids. Foods and especially liquids will release moisture and cause the refrigerator to use more energy.
Full freezers operate more efficiently.
If your freezer isn't full, fill plastic containers with water and freeze them. This will also help in the event of a power outage. Keep the door closed. Freezers Make the most of the freezer compartment in your refrigerator. Since freezers are opened less frequently than refrigerators, frost does not build as quickly.