Freezers

Here are some tips to help keep your freezer running almost as efficiently as it did when it was new.

Keep the freezer two-thirds full. An empty freezer uses more energy to maintain a 0-degree temperature than one that is full. Once frozen, the items in the freezer help maintain the cold, meaning the freezer runs less. If you do not have food to freeze, place bags of ice in the freezer.
Check the door seals. Leaking seals can let warm air back into the freezer. If your freezer has magnetic seals, place a bright flashlight in the freezer and look for light leaks around the door. If it has nonmagnetic seals, open the door and place a dollar bill at the seal and close the door. The bill should be difficult to pull out. Do this on all four sides of the door to check all the seals. If you find a leaking seal try adjusting the door before replacing the seal.
Make sure the freezer has good air flow around it and that the refrigerant coils are clean. To maintain freezing temperatures inside, the coils must get rid of a lot of heat. If the coils have poor airflow around them or are covered with dust, it is harder for them to transfer that heat.
Defrost the freezer. Manual defrost freezers should be defrosted when the ice becomes 1/4-inch thick on the walls of the freezer. Ice build-up makes the compressor run longer to maintain a cold temperature.
Buy the right-size freezer. If you are going to buy a used freezer, buy one that fits your needs. It may be tempting to by a larger freezer, but they use more energy than smaller ones.