A water cooler is a free-standing device that dispenses water from removable 4- to 5-gallon plastic bottles usually placed on top of the cooler. Water coolers and hot/cold water dispensers consume more than 4 billion kWh per year and cost American companies about $300 million annually to operate [U.S. Environmental Protection Agency/Department of Energy. 2000. "ENERGY STAR". Washington, D.C.: U.S. Environmental Protection Agency/Department of Energy].  A preliminary analysis for EPA found that hot/cold dispensers consume about 2 kWh per day, whereas cold-only dispensers consume an order of magnitude less energy. Approximately 90 percent of hot/cold water dispenser energy use and about 60 percent of cold-only dispenser energy use results from losses during periods when the workplace is unoccupied (i.e., standby losses). The greatest potential for saving energy, therefore, lies in reducing standby energy use. These losses can be reduced by more than 50 percent by implementing currently available, low-cost options such as insulation and timers (ibid.).

Unlike ice makers, there is no test method to compare the energy performance of water dispensers that are sold in the United States (although ARI has a test method for measuring capacity). As a result, no data are published on the relative energy and other performance features of these products.

However, ENERGY STAR worked with drinking water dispenser manufacturers to develop an ENERGY STAR-labeling specification and accompanying test method for water coolers. ENERGY STAR-labeled water coolers use less energy when they are in standby mode (i.e., when they are not heating or cooling water) than standard water coolers. Annual energy savings from an ENERGY STAR water cooler could be as much as $47 per unit.

The following are the specifications for ENERGY STAR-labeled water coolers:

• Cold Only and "Cook and Cold" Bottled Units: < 0.16 kWh/day
• Hot and Cold Bottled Units: < 1.20 kWh/day