Refrigerated vending machines are upright, refrigerated cases whose purpose is to hold cold beverages and vend them in exchange for currency. The entire refrigeration system is built into the machine and heat is rejected from the refrigeration cycle to the surrounding air.
On August 31, 2009, DOE released its final rule for refrigerated vending machines, establishing the first-ever national minimum efficiency standards as mandated by EPAct 2005. The standards became effective in August 2012. Refrigerated vending machines are categorized into two classes: Class A machines have transparent, glass fronts or are fully-cooled; Class B machines have a closed, or opaque, front or are zone-cooled. The standards in the final rule vary by class and are measured by the maximum daily energy consumption (MDEC), in kWh/day, which is a function of the volume of the machine. According to DOE, the beverage machine standards will save about 16 billion kWh of electricity (or 0.16 quad of primary energy), save consumers $500 million in energy costs, and eliminate nearly 10 million metric tons of carbon dioxide emissions.
In January 2016, DOE published updated standards for beverage vending machines (BVM) that cut energy use by 25-65% relative the least efficient machines available now. They apply to both common BVM and to combination BVM, where the machine includes both a refrigerated section to cool and hold beverages, as well as a non-refrigerated section to hold snack items.
A key innovative element of the new standards is crediting energy-saving control strategies, including lighting controls and refrigeration system controls. Lighting controls automatically dim or turn off the lights illuminating the beverages and any signage during periods when a building is closed or there is low customer traffic, while refrigeration system controls allow the temperature of the beverages in the machine to rise a few degrees during periods of extended inactivity.
In 2005, there were an estimated 3.67 million machines in the U.S, 95% of which were designated Class B where the front is opaque so inventory is not visible to the consumer. Energy consumption is a function of the cooling load that the machine must meet, which typically comprises 65–76% of the total energy consumption of the machine. Lighting accounts for another 5–20% of total energy consumption. Annual energy consumption for the various sizes of refrigerated vending machines averages around 2000 kWh.