6.5 Clothes Washers

Energy Use in Clothes Washers and Dryers

Clothes washers and dryers together account for approximately 10 percent of residential energy consumption. However, the majority of this energy is consumed by the washer, specifically for heating water.

• Water Heating: An estimated 85–90 percent of the energy used by a clothes washer goes toward heating the water.
• Mechanical Operation: Only 10–15 percent of the energy is used by the washer's motor and controls to agitate and spin the clothes.

A typical household completes nearly 300–400 loads of laundry per year. A conventional washer uses approximately 40 gallons of water per load. Therefore, the most effective way to reduce energy consumption in laundry is to reduce hot water use.

How Clothes Washers Work

The basic principle of cleaning clothes has remained unchanged for centuries: wet the garment, agitate it to loosen dirt from the fibers, and rinse the dirt away with fresh water. While early methods involved pounding garments with stones, modern machines use mechanical agitation and heated water to improve cleaning efficiency.

What has changed over time is the method of agitation. Today, there are two primary types of clothes washers available to consumers:

1. Vertical Axis (V-Axis): Commonly known as top-loading washers.
2. Horizontal Axis (H-Axis): Commonly known as front-loading washers.

Text description of the Sketch of front-loading and top-loading washing machines.

The image features a comparison between two types of washing machines: a front-loading machine on the left, labeled "A," and a top-loading machine on the right, labeled "B."

On the left, "A" is a front-loading washer with a circular door and a view of the interior drum. The diagram indicates a "Tumble" action with a curved arrow encircling the drum. The water level reaches just below the laundry.

On the right, "B" is a top-loading washer shown as a cylinder filled over halfway with water, with laundry floating inside. An agitator is present in the center, indicated by arrows showing "Agitation." The water level is significantly higher compared to the front-loading washer.

Credit: Image created with Copilot

Comparing Washer Types

Vertical Axis (Top-Loading) Most clothes washers historically produced for the U.S. market are vertical axis (V-axis) models with a central agitator. In these machines, clothes are suspended in a tub filled with water for both washing and rinsing. Because the tub must be filled completely to cover the clothes, these models generally use more water and, consequently, more energy to heat that water.

Horizontal Axis (Front-Loading) Horizontal axis (H-axis) washers are common in Europe and are becoming increasingly popular in the United States. Instead of an agitator, these machines tumble the load repeatedly through a small pool of water at the bottom of the drum.

• Efficiency: This tumbling action reduces the need for water, which directly reduces the energy required to heat it.
• Potential Savings: Estimates show that replacing conventional V-axis washers with H-axis designs could save a significant quantity of energy and water nationwide.

Features of Front-Loading Washers

Front-loading washers or tumble-action machines lift and drop clothes rather than moving them around a central axis. They often include advanced features to optimize energy and water use:

• Auto Temperature Control: The machine mixes hot and cold water to reach a preset "warm" or "cold" temperature. This ensures the water is warm enough for detergent to dissolve effectively, even when incoming tap water is very cold (such as during winter).
• Smart Water Levels: High-end models sense the load size and automatically adjust the water level. Most machines, even basic models, offer multiple water level settings to prevent waste.
• High-Pressure Rinses: To reduce water consumption, these machines often spray clothes with high-pressure rinses to remove soap residue rather than soaking them in a full tub of rinse water.
• Capacity: Front loaders generally hold more clothes than top loaders because they do not require space for a central agitator. This allows for larger loads, potentially reducing the total number of cycles needed per week.

Consumer Actions for Energy Conservation

Consumers have significant power to reduce energy use through their laundry habits and purchasing choices.

Operational Tips:

• Wash Full Loads: Washers are most efficient when operated at full capacity.
• Use Cold Water: Washing clothes in cold water conserves significant energy (by avoiding water heating) and is recommended for colored and delicate fabrics.

Purchasing Tips:

• Consider Front Loaders: Since they use less water, they require less energy to heat that water. The most efficient front loaders use less than half the amount of water used by average top loaders. These models use 45% less energy and 50% less water than top load impeller washers.
• Look for ENERGY STAR®: Purchase washing machines with the ENERGY STAR designation. ENERGY STAR certified clothes washers use 14 gallons of water per load versus 20 gallons in a standard machine.