Energy efficiency standards for appliances and equipment reduce energy use  in residential and commercial buildings and the associated greenhouse gas emissions. In 2011, buildings , and the appliances and equipment used inside of them, accounted for 34 percent of U.S. greenhouse gas emissions (emitted either directly from the buildings or in the generation of the electricity used in the buildings).
Laws authorizing the U.S. Department of Energy (DOE) to set appliance and equipment efficiency standards were first enacted in the 1980s and have since been expanded to new categories of equipment. DOE also is required to periodically strengthen existing standards. In setting a standard, DOE must take into consideration factors including increased cost of the product, lifetime operating cost savings, total projected energy savings, the need for national energy savings, impacts on product performance, and impacts on manufacturer competition. Altogether, the new and strengthened 2013 standards are expected to cumulatively save between $4.9 billion and $16.3 billion and prevent the emission of 300 million tons of CO2.
DOE recently set new energy efficiency standards for microwave ovens and distribution transformers:
Metal halide lamp fixtures. Metal halide lamp fixtures provide lighting for parking lots and streets, flood lighting, athletic facilities, big-box stores, and warehouses. Standards for this equipment were first established in the Energy Independence and Security Act of 2007. Strengthened standards were issued by DOE in a final rule on February 10, 2014. These standards are expected to save consumers from $950 million to $3.2 billion by 2046 and avoid the emission of 22.5 to 27.8 million metric tons of CO2.
External power supplies. External power supplies are the boxes on power cords that convert household electric current into direct current or lower-voltage alternating current in order to operate consumer products, such as computers or cell phones. Standards for this equipment were first established in the Energy Independence and Security Act of 2007. Strengthened standards were issued by DOE in a final rule on February 10, 2014. These standards are expected to save consumers from $1.9 billion to $3.8 billion by 2044 and avoid the emission of 47 million metric tons of CO2.
Commercial refrigeration equipment. Commercial refrigeration equipment is used for food storage and merchandising in the food retail industry (e.g., grocery stores, supermarkets convenience stores, specialty food stores) and the foodservice industry (e.g., restaurants and cafeterias). Standards for this type of equipment were first established in the Energy Policy Act of 2005. Strengthened standards were issued by DOE in a final rule on March 28, 2014. These standards are expected to save businesses between $4.9 billion and $11.7 billion by 2047 and avoid the emission of 142 million metric tons of CO2.
Walk-in coolers and freezers. The coolers and freezers covered by the new standards are used to store refrigerated or frozen food or other perishable goods, and are used primarily in the food service and food sales industry. Coolers and freezers covered by the regulations are enclosed storage spaces that can be walked into, have a total chilled storage area of less than 3,000 square feet, and do not include products designed and marketed exclusively for medical, scientific, or research purposes. The 2013 standards for walk-in coolers and freezers set a minimum R-value* for insulating panels, as well as requirements for doors, door closures, motors and lighting. Standards for this equipment were first established in the Energy Independence and Security Act of 2007 . In May 2014, DOE issued a final rule that would avoid the emission of 159 million metric tons of CO2 by 2046. The rule will go into effect in 2017. (*R-value is a measure of the amount of insulation provided. For example, insulation panels with a higher R-value will allow less heat to pass through them.)
Electric motors. Electric motors convert electric energy into rotational energy and are often used for blowers, compressors, conveyors, fans, and pumps. There are three categories of electric motors, defined, among other ways, by their voltage, power, and rotation speed. Standards for this equipment were first established in the Energy Policy Act of 1992, but the Energy Independence and Security Act of 2007 significantly expanded the scope of covered motors. In May 2014, DOE issued a final rule for electric motors that would avoid emission of 395 million metric tons of CO2 by 2044. The rule will go into effect in December 2015.
Furnace Fans. Furnace fans circulate heated air through a home’s duct system. Standards for this equipment were first authorized in the Energy Policy and Conservation Act of 1975. In June 2014, DOE announced the first ever energy efficiency standard for furnace fans. This standard will avoid the emission of 181 million metric tons of CO2 by 2048 and go into effect in 2019.
DOE is currently considering establishing or strengthening energy efficiency standards for these categories of appliances and equipment: