Function

• Dishwashers utilize hot water and dish detergent to clean the dishes in them. According to the U.S. Department of Energy, the standard dishwasher uses about 12 gallons of water per cycle. However, ENERGY STAR dishwashers made after August 2009 are required to use only 5.8 gallons of water per cycle or less. Comparatively, a dishwasher made before 1994 uses more than 16 gallons of water.
  
  

Load Size

• The size of the load placed in the dishwasher often has no effect on how long the washer runs and how much water is used. Waiting to run the dishwasher until it has a full load can reduce the number of times you run the washer and accordingly reduce the amount of water used over time.
  
  

Considerations

• According to Energy Savers, the majority of the energy consumed by the running of a dishwasher comes from heating the water. This means that cleaning dishes by hand with a stream of running hot water may not save a significant amount of energy over running a dishwasher.