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Refrigerators

* Replace all models manufactured before 2001.

New refrigerators consume 75 percent less energy than those produced in the late 1970s, and are even more efficient than models just six years old, according to research done at the University of Michigan's Center for Sustainable Systems. The newest federal standards went into effect in 2001—so if you need to make repairs on an older fridge, it's worth getting a new one instead.

When replacing your refrigerator, opt for a top-freezer configuration rather than a side-by-side, and make sure it's Energy Star-certified. A new refrigerator should then last you about 14 years.

Resist the urge to hold on to your old fridge or give it away, since inefficient old models can cost over $100 a year to run. Most communities have specific requirements for disposing of refrigerators and other large appliances; visit www.earth911.org for information in your area.

Dishwashers

* Replace non-Energy Star models.

Newer, more efficient dishwashers use less hot water, have energy-efficient motors and use sensors to determine the length of the wash cycle, making Energy Star models 25 percent more efficient than the minimum federal standards. This can mean a savings of $25 a year if you replace a pre-1994 machine. When shopping for a new dishwasher, choose one with a "light wash" or "energy saving" cycle—and expect to hang onto it for about 9 years, suggests the National Association of Home Builders. And remember that handwashing dishes is an inefficient alternative, generally wasting more water than dishwashers.

To recycle appliances, check with your local sanitation department or visit www.Earth911.org.