Most of the energy used by a refrigerator is used to pump heat out of the cabinet. A small amount is used to keep the cabinet from sweating, to defrost the refrigerator, and to illuminate the interior.
The efficiency of a refrigerator is based on the energy consumed per year for a given size. The efficiency of a refrigerator is expressed in volume cooled per unit electric energy per day. Volume is measured in cubic feet and electrical energy is measured in kilowatt-hours.
The energy efficiency of refrigerators and freezers has improved dramatically over the past three decades. The most energy efficient refrigerator of 2025 was a Samsung RS24T5202. It has the capacity of most other models (27.4 ft3), but uses only 546 kWh/year.
You can explore more types of energy efficient appliances on the energy star website. Also, Energy Star as a calculator to determine how much energy you could save by upgrading your current fridge to one that is more efficient!
Energy Guide Labels
Refrigerators now come with an EnergyGuide label that tells you in kilowatt-hours (kWh) how much electricity a particular model uses in a year. The smaller the number, the less energy the refrigerator uses and the less it will cost you to operate.
- Full-sized refrigerators that exceed the federal standard by 15% or more (and full-sized freezers that exceed it by 10%) qualify for the ENERGY STAR label.
- Compact refrigerators and freezers must exceed the standard by 20% to qualify for ENERGY STAR.
How to keep your refrigerator running efficiently
- Keep your refrigerator or freezer at the following temperatures: 37–40°F for the fresh food compartment of the refrigerator, 0–5°F for the freezer section. Use a thermometer to check inside temperatures.
- Regularly defrost manual-defrost refrigerators and freezers; don't allow frost to build up more than 1/4 inch.
- Make sure your refrigerator and freezer door seals are airtight. Check the seal on door gaskets periodically by closing the door on a dollar bill. If it pulls out easily, you may need a new gasket.
- Keep the doors closed as much as possible and make sure they are closed tightly.
- To ensure proper cooling of its contents, don't crowd food items. Too many dishes obstruct air circulation.
- Cover liquids and wrap foods stored in the refrigerator. Uncovered foods release moisture and make the compressor work harder.
- Replace paper wrappings on food items with aluminum foil or plastic wrap. Paper is an insulator.
- Placement of the refrigerator is very important. Direct sunlight and close contact with hot appliances will make the compressor work harder. More importantly, heat from the compressor and condensing coil must be able to escape freely, or it will cause the same problem. Don't suffocate the refrigerator by enclosing it tightly in cabinets or against the wall.
- Regularly brush off or vacuum the refrigerator coils on the back or bottom of the unit.
- Because most refrigerators reject heat from the bottom and/or back, they need adequate clearance to allow sufficient airflow. While no specific studies have been done to calculate the optimum clearance space, one general rule-of-thumb is to double the space recommended by manufacturers for refrigerator installation. Another rule-of-thumb is to allow 2 inches of air flow around the refrigerator.
- Don't keep that old, inefficient fridge running day and night in the garage for those few occasions when you need extra refreshments. A 15-year-old refrigerator could cost $100–$150 per year.