Dishes: Hand Washing vs. Dishwasher

Water Consumption

• Some people believe dishwashers use more water than water used when hand-washing dishes, but this isn't necessarily true. According to the U.S. Department of Housing and Urban Development (HUD), an Energy Star--rated dishwasher --- 2009 to the present models --- uses approximately 6 gallons of water. Older models can use anywhere from 10 to 25 gallons of water, so it is in the homeowner's best interest to replace models older than those built in 2008 with energy-efficient models. In addition, HUD reports that hand-washing your dishes will use 5 to 86 gallons of water. Running water during hand dish washing is, perhaps, the biggest water-consuming culprit. The King County Water Conservation Program maintains that for every minute a faucet is left running, 3 gallons of water run down the drain. To save water, change the aerator on your faucet to a 1.0 gpm model to reduce the flow rate for your faucet. Instead of running the faucet for rinsing dishes, fill both sink sides with water, and use one basin to wash the dishes and one to rinse.

Energy Consumption

• A water heater must heat water to create hot water and, according to the U.S. Department of Energy, this factor accounts for the largest costs involved with dish washing. The other consumer of energy on the dishwasher is the drying unit. By turning off the drying unit on the dishwasher and/or opening the dishwasher door to allow dishes to air-dry, you can save money and decrease your energy consumption. Because washing dishes by hand usually consumes more hot water than running an energy-efficient dishwasher, hand-washing dishes, on the average, consumes more energy than a dishwasher. Make sure your dishwasher is loaded correctly and is full before you run it to maximize your energy usage and reduce the number of loads you must wash.

Time Consumption

• Loading dirty dishes into a dishwasher and then turning it on and leaving while you do other chores or activities requires less time than hand-washing dishes. Hand-washing dishes requires the person washing the dishes to scrape and rinse dishes before washing, wash the dishes --- usually in an organized fashion with glass, then plastic, then metals --- and then rinse the dishes. Dishes must then be placed on a drying rack or towels and allowed to air-dry, or dishes must be towel-dried. When the dishes are dried, they must be put away in time to create necessary space for a new batch of dishes to be air-dried. In kitchens with a limited amount of counter or sink space, a drying rack may be more of a nuisance, and you might not have the space at all.

Sanitization

• Hand washing allows the dishwasher to individually scrub each dish or utensil, but a dishwasher relies on spray arms and jets of water that sometimes don't reach into every crevice. On the other hand, hot water is usually set at a temperature of 120 degrees Fahrenheit, but a dishwasher with a booster heater can increase the water temperature to 140 degrees Fahrenheit. According to the U.S. Department of Energy, 140 degrees Fahrenheit is the recommended water temperature for sanitary dish washing.