Let’s face it. In this day and age, there are still some people that prefer to hand wash their dishes. Many people from older generations prefer this method because they feel it gets the dishes cleaner because each dish is given individual attention. The fact is that washing dishes by hand can use up to 20 gallons of water each time you wash a load.
Dishwashers have gotten a bad reputation in the past because many feel the time spent rinsing and loading them can be better used by just washing the dishes by hand. Why should you have to rinse the dishes before putting them into a wash cycle? Right?
Older dishwashers can use about 15 gallons of water with each load, which really isn’t that great. Considering hand washing uses 20 gallons of water, using the dishwasher isn’t a bad idea. You should also remember that a dishwasher can provide your dishes with a scrubbing in water much hotter than your hands can stand. Hot water is a great way to get rid of the dirt and grime accumulated on your dishes.
If you are considering switching to a dishwasher, here are a few things for you to consider:
- New energy and water efficient models save water. The new and improved designs of dishwashers use a smaller amount of water and energy (3 gallons of water and 1 kilowatt-hour of energy) per load.
- Only run your dishwasher when it is full. The best way to save water, energy and money is to make sure the dishwasher is completely full before running it. Washing partial loads wastes water and energy.
After you review all the information and decide you still prefer to wash your dishes by hand, there are a few things you should remember.
- Never let the water run while you wash dishes. Fill a basin or tub to fill up with soapy water or plug the sink to wash dishes.
- Rinse only when you have a large amount of dishes washed. Instead of rinsing each dish individually, rinse when you have a large amount of dishes washed to save water.
The washing time involved with a dishwasher is minimal in cost. The drying time can be expensive at 1500 watts per cycle. Air dry the dishes or dry them by hand.
Dishwasher Water Use :
Table 1: Dishwasher water use rates, national average
| National Average | |
| Dishwasher Load Volume | 9.3 gallons |
| Daily Per Capita Use | 1.0 gallons |
| Frequency of Use | 0.1 loads per capita per day |
Dishwasher Water Savings
Running a full load of dishes in a dishwasher should save water over washing the same dishes by hand. A typical dishwasher uses between 8 and 15 gallons per load of dishes with an average of about 9.3 gallons per load.
Some manufacturers do offer high-efficiency dishwasher models. These dishwashers use less water and more significantly, less energy than the standard models. A high-efficiency dishwasher can wash a load of dishes using 5 to 7 gallons of water.
A family that replaces a 12-gallon per load machine with a 6-gallon per load machine, and runs their dishwasher 4 times per week will save about 1,250 gallons of water per year.
Dishwasher Wastewater Savings
Running a full load of dishes in a dishwasher should save water and wastewater over washing the same dishes by hand. A typical dishwasher uses between 8 and 15 gallons per load of dishes with an average of about 9.3 gallons per load.
Some manufacturers do offer high-efficiency dishwasher models. These dishwashers use less water and more significantly, less energy than the standard models. A high-efficiency dishwasher can wash a load of dishes using 5 to 7 gallons of water.
A family that replaces a 12-gallon per load machine with a 6-gallon per load machine, and runs their dishwasher 4 times per week will save about 1,250 gallons of water and wastewater per year.
Energy Savings
The efficiency of a dishwasher is measured by a term called the energy factor. The energy factor is somewhat similar to the miles per gallon for a car, but in this case the measure is cycles per kilowatt-hour of electricity.
The minimum allowed energy factor rating for standard capacity dishwashers is 0.46. About 80% of the total energy used by a dishwasher goes towards heating the water. So the best way to improve the efficiency of a dishwasher is to reduce the amount of water needed to clean the dishes.
New dishwashers use about half the electricity of 25-year-old models. Most new dishwashers have a built-in booster heater, which raises the water temperature of the water during wash cycles to 140°F to kill germs and cut grease.
While this feature adds somewhat to the dishwasher’s electric demand, it enables you to lower the thermostat setting on your hot water heater to 120°F. Each 10°F reduction in the water heater temperature setting will save up to 13% of your hot water heating bill and also reduce the danger of scalding.
Most manufacturers offer high-efficiency dishwasher models. These dishwashers use less water and more significantly, less energy than the standard models. A typical high-efficiency dishwasher can wash a load of dishes using 5 to 7 gallons of water and use substantially less energy. Estimated annual energy use for high-efficiency dishwashers ranges from 214 to 558 Kilowatt-hours (kWh) per year with an average of 504 kWh.
Federal law requires that EnergyGuide labels be placed on all new dishwashers. These labels are bright yellow with black lettering. Look for the EPA’s ENERGY STAR label when purchasing a new dishwasher. This label indicates the machine is energy efficient. For information on the Energy Star program, specific high efficiency dishwashers, and where to purchase these machines visit the Energy Star web site.
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