Vacuum cleaners have been around for a hundred years. Can you imagine your home without a vacuum cleaner? Before vacuum cleaners, people used brooms to remove dirt from bare floors. Rugs were taken outside once or twice a year, hung on clotheslines, and hit with rug beaters to remove the dirt. Wall-to-wall carpeting would be unheard of without the existence of vacuum cleaners to remove the dirt.

Vacuum cleaners use suction to remove dirt. Suction is the basic principle behind drinking soda through a straw. Vacuum cleaners use a fan to pull air through the machine and out an exhaust port. Just moving air, however, would not remove dirt. The air pressure drops behind the fan, creating a partial vacuum which in turn creates suction. Many vacuum cleaners have rotating brushes, either mechanically or electrically operated, called beater brushes, which loosen the dirt and debris from the carpet or rug.

The other essential part of a vacuum cleaner is the dirt collection system. For years, this was a cloth or paper bag. Without a collection system, the dirt would just be blown back out into the room. Today, some vacuum cleaners use cups to catch the dirt. Others route the route of air through water, which captures the dirt. This is true whether it is a canister-type machine or a stand-up machine.

Because the bag that catches the dirt has to be in the line of air movement, as the bag fills, it blocks air flow and thus suction decreases. The newest, cyclone types of vacuums use centrifugal force to send the dirt to the outside of the airflow cylinder where, released from the path of the air, it falls harmlessly to the bottom, into a collecting container. Because the dirt does not collect in the path of air movement, suction does not decrease and stays powerful.