Energy-Saving Dishwashing Tips

Feb 23, 2010 | Energy Efficiency, Water Conservation

Snapshot | Take action!

You can trim energy costs by making small changes (and a few big ones) to your dishwashing routine. Reducing how much hot water you use to clean dishes is central to saving.

1. First, reduce dishes to be washed. Reuse drinking glasses and cups, and plan ahead as you cook so you can use barely soiled pans, such as pots used for boiling, for other purposes.

2. By hand or machine? An age-old debate is whether it's best to wash dishes by hand or with a dishwasher. Most people use about 5 to 8 gallons of water to hand wash a load of dishes, water mostly used in rinsing. If you use a faucet aerator or sprayer or just take extra care, you might use only 4 to 5 gallons to wash the volume of dishes that would fill your dishwasher. That's about equal to an efficient compact dishwasher. Most dishwashers use 4 to 6 gallons per load.

Here are some more tips for dishwashing efficiency.

• Do not leave water running when rinsing dishes.

• Don't fill the sink to the brim with water.

• Disinfect without scalding. If you are washing dishes with super-hot water for fear germs will live on the dishes, instead immerse the dishes in a final soak of water with a a capful of hydrogen peroxide. It will kill most germs and allow you to avoid a rinse with near-boiling water.

• Wash only full loads. The dishwasher will use the same amount of water if it is half full or completely full.

• Do not pre-rinse dishes. Most newer dishwashers do not require a pre-rinse. Scrape food into your compost collector, garbage grinder, or trash. If you must rinse first, use cold water.

• Use the "energy-saving" setting. If your dishwasher has one, use this to save energy by using less water and running for a shorter cycle.

• Air dry. Cut 15% power use of your dishwasher by selecting the air-dry or "no heat" dry option on your dishwasher. The no heat option uses a fan only to dry dishes. Or simply open the door after the wash cycle.

• Turn down your water heater. Since most dishwashers (except very old ones) have booster heaters that heat water up to grease-dissolving temps of 140°F to 145°F (60°C to 63°C), you can lower the setting on your home water heater to 120°F (49°C). Every 10°F (5.5°C) reduction in water heating temperature settings results in a 3% to 5% reduction of energy consumption for water heating.

• Go small. If you buy a new dishwasher, think about getting a compact dishwasher-about 18 inches wide versus the 24 inches of a standard dishwasher-which uses less water and energy per wash. But if you have to use a dishwasher more than once a day, it is likely more efficient to use a standard size.

• Get a new one. If your dishwasher is 10 or more years old, get an energy-efficient dishwasher, preferably an ENERGY STAR-approved model with a smart sensor that adjusts the wash cycle to match the load. These can save up to 20% on water heating costs.

Use full loads in dishwasher

Use economy settings on dishwaser or air dry