How do washing machines get clothes clean?

Top-loading and Front-loading Washers

A top-loading washing machine showing the agitator in action
A top-loading washing machine showing the agitator in action

While the mechanical features mentioned earlier in this article are common to almost all washing machines, not all washing machines wash your clothes in the same way. There are two main types of washing machine you might have in your home or find in a laundromat. One type is top-loading with a lid on top and an upright basket. The other type is front-loading with a door on the front and a sideways-mounted basket. There are benefits and drawbacks to both types.

Top-loading washing machines use an agitator to move clothes around the basket. The agitator is a vertical device in the center of the basket with ridges that help push the clothes. The agitator alternates directions on that vertical axis. This movement creates the friction the top-loading machine needs to loosen dirt from fabrics. Some washers also have a fabric-softener dispenser mounted on the top of the agitator.


A front-loading washing machine, empty, with one of the paddles visible
A front-loading washing machine, empty, with one of the paddles visible

Front-loading washing machines use paddles that extend a short ways from the sides of the basket inward toward the center. The paddles help move the clothes and stir the water while the basket turns. Like the agitator in top-loading machines, the paddles loosen dirt from fabrics by creating friction.

High-efficiency front-loading washing machines are growing in popularity because of their low environmental impact. This is because they use less water and detergent to clean the same amount of clothes as the top-loading machine. One disadvantage they have, though, is that they seal and lock at the beginning of the wash program and can't be opened again until the end. The lid on a top-loading machine, though, can be opened any time you need to check the load or add something.

The U.S. Environmental Protection Agency and the U.S. Department of Energy have put pressure on appliance manufacturers to product energy-efficient models. The pressure comes from their Energy Star program, which identifies products that meet a target level of efficiency. Most high-efficiency washing machines are front loaders. Manufacturers recommend only using detergents designed for high-efficiency washing machines because they don't fill the washer with excessive suds.