Dishwasher Economics

Energy Star® labeled dishwashers use at least 41% less energy than dishwashers meeting the federal minimum standard. Most of the energy used by dishwashers is actually the energy required for heating the water they consume. So the most efficient dishwashers use less hot water to wash dishes than their competitors.

Many newer dishwashers also use significantly less water than hand-washing dishes – as much as one-half less. Like clothes washers, dishwashers conserve energy and water when using their low and medium cycles. Water usage varies from a low of 7 gallons, for the light wash, to a high of 14 gallons for the heavy-duty cycle.

The most energy efficient dishwashers incorporate soil-sensors to adjust water use depending on how dirty the dishes are in each load washed. An improved dishwasher test procedure, used to provide the information on the EnergyGuide labels, gives a more realistic estimate of the energy consumption of soil-sensing dishwasher models. Be sure to read the EnergyGuide labels whenever you buy a new dishwasher or other appliance.

Recent studies demonstrate that most new dishwashers do a great job cleaning even the dirtiest dishes without hand-rinsing. In a recent study, dishwashers were compared to doing the job by hand. The dishwasher was more efficient and got the dishes cleaner than its human counterparts.

Run your dishwasher with a full load and avoid heated drying. Also avoid pre-rinse and rinse-hold options for the most energy efficient dishwashing operation.

Residential Energy has more information on dishwashers in Chapter 7.The Homeowners Handbook to Energy Efficiencyhas more information on saving energy with home appliances.