Refrigerators are classified based on several characteristics: the type of unit (refrigerator, refrigerator-freezer, or freezer); geometric configuration for refrigerator-freezers (i.e., freezer mounting on top, side, or bottom); size of the cabinet (standard or compact); type of defrost system (manual, partial, or automatic); and the presence or absence of through-the-door (TTD) ice service.
In August, 2011, DOE issued updated standards for refrigerators and freezers based on a joint recommendation submitted by efficiency proponents and manufacturers. The new standards took effect in Fall 2014. The standards are expressed as the maximum annual energy consumption for a product as a function of the product's adjusted volume. In its analyses, DOE found that technology options, including improved compressor efficiency, brushless DC evaporator and condenser fan motors, and vacuum insulation panels (VIPs), could lead to cost-effective energy savings in the range of 20-30% depending on the product class. DOE estimates that updated national standards would save about 4.8 quads of primary energy cumulatively by 2043 and generate up to $36 billion in net present value savings for consumers.
ENERGY STAR qualified refrigerator/freezers must achieve at least 10% savings relative to the national standards which became effective in 2014.
The story of residential refrigerator efficiency since the mid-1970s is one of the greatest success stories of appliance efficiency standards. Six iterations of standards (three adopted by California and then by other states, and three adopted nationally) have driven the energy use of a typical new refrigerator from about 1,800 kWh/yr in 1972 to less than 500 kWh/yr today. The new standards will save another 25% for the major product classes. Even as new standards became effective, innovation and competition drove down the cost of refrigerators. At the same time, the typical refrigerator has gotten bigger and better, often including features like ice-makers and auto-defrost. Manufacturers will likely use improved insulation, improved compressor efficiency, improved heat exchange in the evaporator and condenser, efficient fan and fan motors, and improved temperature control to meet the 2011 standards. The refrigerator graph shows the steady decline in refrigerator energy use over the past 35 years and demonstrates that as new standards became effective, innovation and competition drove down the cost of refrigerators.