Horizontal-axis clothes washers save energy because they use less water. Most of the energy needed for clothes washing goes to heating the water.

Conventional washers use a large vertical drum to soak and wash the clothes. Most high-efficiency clothes washers have a horizontal-axis drum, which tumbles the clothes through a pool of water.

Recent technological innovations have resulted in vertical-axis washers that can achieve similar energy-efficiency levels. High-efficiency washers use up to 18 gallons less water per load and remove more moisture from the clothes with a high-speed spin cycle. As a result, energy costs can be reduced as much as 50 percent.

In addition, manufacturers say high-efficiency machines get clothes cleaner and are gentler to fabrics.