Dishwasher

A dishwasher is an electrical appliance that cleans dishes, glasses, utensils and other food-contact items using hot water and detergent. The machine operates by spraying water forcefully over the items, replacing manual washing and scrubbing by hand.

Two main types exist: domestic models, typically installed below the kitchen counter, and commercial models (for restaurants and large food services) that process larger quantities rapidly. Domestic dishwashers have standard widths of approximately 60 centimeters, and compact models measuring 45 centimeters.

How it works

Items are placed in wire baskets where water can reach all surfaces. When the cycle starts, the machine draws in water and heats it in an electric heating element or heat exchanger. The water is sprayed through rotating arms with holes, forcing it against the dishes with pressure. Specialized detergent removes food residue and grease. After washing, a rinse cycle with clean water follows, and finally the items are dried with heat or air.

Key components

Essential parts include the water pump and spray system, the rotating spray arms, the food trap filter, the heating element, and the control panel regulating cycle time and temperature. Many machines also have a water softener compartment to remove mineral hardness from water, and a rinse aid dispenser that helps prevent spots and streaks on dishes.

Water and energy use

Each washing cycle uses a set amount of water. When fully loaded, water consumption is often less than hand washing with running water. Eco or energy-saving cycles run longer but use lower temperatures and less energy. Dishwasher detergent differs from hand-washing soap; using the wrong product can cause excessive foaming and machine damage.

Limitations

Not all items are dishwasher-safe. Wooden boards, cast iron, delicate decorative items, and some soft-metal items can be damaged by heat and strong detergent. If the filter is not cleaned regularly, buildup and reduced performance may result.