Check out our store for energy conservation books and online training for energy auditors and other job skills.
The U.S. Department of Energy is changed its rating for washing machines in 2004. The Energy Factor (EF) is the old rating and describes how many cubic feet of clothes can be washed per kilowatt-hour of electricity consumed. The Modified Energy Factor (MEF) is the new rating that describes not only how many cubic feet of clothes can be washed, but also how many kilowatt-hours electricity are needed to dry those clothes. For this reason the MEF gives higher ratings to washers that spin clothes drier than for clothes washers that leave more water in the clothes.
The most efficient new clothes washers currently have an MEF in the range of 1.7 to 2.2. In 2003, washers that earned the Energy Star® qualification were required to have an MEF of 1.26. In 2005 they’ll need an MEF of 1.42. Whenever you shop for a new appliance, look for the Energy Star® label to get these best ratings.
The efficiency of clothes washers – in both water and energy use – has increased by a factor of five during the past 20 years. The best new horizontal-axis clothes washers use far less energy and water than older vertical axis machines. They do this by washing in less water, and rotating faster on the spin cycle. The horizontal-axis washers may cost more, but will often repay this initial investment in 3 – 6 years through energy savings.
Most of the energy used by the American clothes washer is consumed by the water heater. Remember that clothes washers often perform as well with cold water as with warm or hot water, especially with lightly soiled clothes. For best results, use an enzymatic detergent designed for cold water. And wait until you have a full load of laundry, since a full clothes washer uses energy most efficiently. With partial loads, experts recommend using the water-level controls that describe the load’s size – small, medium, normal, or large.
The Homeowners Handbook to Energy Efficiency contains simple, practical energy-efficiency ideas.