Curious how the Department of Energy's number-crunchers measure the efficiency of washing machines?
MEF = C / (MEETDE)
C = capacity (cubic feet or liters)
ME = energy used per cycle
ET = energy used to heat water per load
DE = energy to dry the load.
Benefits of High-efficiency Washers
Performance should be the most important factor in selecting a new washing machine, and most experts agree that high-efficiency washers are able to get clothes just as clean as, if not cleaner than, traditional washers.
Frayed and worn-looking jeans are still fashionable, but if you have a high-efficiency machine, you'll have to find another way to give your clothes that punk-rock look. High-efficiency machines are proven to put less wear and tear on fabric because they have gentler spin cycles. Unlike agitator-style washers, which actually beat the filth out of fabric, high-efficiency models toss and tumble clothes until they're clean.
Removing the agitator from the tub also creates more space, meaning that high-efficiency washers have greater capacity. Running fewer loads of laundry saves energy and water (and it can also mean less bending over, if you have a front-loader). Front-loading washers not only save space inside the machine; they can also have a dryer stacked on top of them, saving a few feet of floor space.
Because high-efficiency machines tend to have more customized settings, it's easier for users to find a setting that's right for a particular load, providing a better wash cycle. And although the wash cycle takes longer for high-efficiency machines, spin cycles remove more water from fabric, which allows for shorter drying times.
They also use less energy. All current Energy Star-rated machines are required to use 30 percent less energy than traditional models, and most high-efficiency washers use at least 50 percent less water. In some cases, the water level is so low that you can't even see it.