Vacuum cleaner is an electric appliance that uses suction to clean. Vacuum cleaners remove dirt and other materials from carpets and bare floors. They also may be used to remove dust and dirt from furniture, woodwork, curtains, and other above-the-floor items. The first vacuum cleaning devices were developed about 1900.
A vacuum cleaner works by means of a suction fan, which creates a partial vacuum within the machine. Outside air, which always tries to fill a vacuum, flows rapidly into the cleaner, drawing in dirt. A bag or other filtering device traps the dirt, and the cleaned air leaves the machine as exhaust. The filtering device must be emptied or changed regularly.
There are two main kinds of portable vacuum cleaners: (1) canisters and (2) uprights. In a canister model, a powerful suction fan pulls dirt-laden air into a bag through a hose to which a variety of nozzles can be attached. Most upright models have a small fan and an agitator in the base. The agitator is a rotating cylinder with bristles that loosen dirt. The airflow pulls the loosened dirt through the fan. The dirt-laden air is blown into the filtering device, which is usually attached to the machine’s handle. The term combination cleaner is generally used to identify a canister cleaner equipped with a rotating agitator for loosening dirt in the carpet.
Other types of portable vacuum cleaners include handheld and utility vacuum cleaners. A handheld model can be held in one hand and is used primarily for above-the-floor cleaning and for stairs. A utility vacuum cleaner is a type of canister used to pick up large particles of dirt and debris, especially in home workshops. Some utility models are designed to pick up liquid.
Stationary or built-in vacuum cleaners are called central vacuum cleaners. They have various kinds of nozzles and a hose that connects to a special fitting on the wall. Dirt moves from the hose through a network of ducts to a remotely located dirt-collecting system.
