Ask a group of people if it’s best to rinse – or simply scrape — the dishes before loading them into the dishwasher, and you’re likely to get a discussion worthy of the U.N. Council on Foreign Affairs.
For the final word, we consulted the American Council for an Energy Efficient America. That group’s advice – whether you’re buying a new dishwasher or using an existing one — is as follows:
- Avoid Hand-Washing
Studies are showing more and more that, when used to maximize energy-saving features, modern dishwashers can outperform all but the most frugal hand washers.
- Scrape, Don’t Rinse
Studies show that most people pre-rinse dishes before loading them into the dishwasher, even though dishwashers purchased within the last 5–10 years do a superb job of cleaning even heavily soiled dishes. If you find you must rinse dishes first, get in the habit of using cold water.
- Follow Manufacturer Instructions
Completely fill the racks to optimize water and energy use, but allow proper water circulation for adequate cleaning.
- Wash Only Full Loads
The dishwasher uses the same amount of water whether it’s half-full or completely full, so nothing will save more energy than waiting to run your dishwasher. If you find that it takes a day or two to get a full load, use the rinse and hold feature common on newer models. This will prevent build up of dried-on food while saving time and water compared to pre-rinsing each item. The rinse feature typically uses only 1 to 2 gallons of water.
- Use Energy-Saving Cycle Options
Pay attention to the cycle options on your dishwasher and select the cycle that requires the least amount of energy for the job. Use the no-heat air-dry feature on your dishwasher if it has one.
- Turn Down the Water Heater Temperature
Since the early 1990s, most dishwashers in the U.S. have been sold with built-in heaters to boost water temperature to 140–145 degrees, the temperature recommended by manufacturers for optimum dishwashing performance. The advantage to the booster heater is that you can turn down your water heater thermostat to 120 dergees (typically half-way between the “medium” and “low” settings).