Reducing the force inside a machine causes suction. The pressure of the surrounding air, created by the atmosphere, is greater than the air inside the machine. The differences in these air pressures can be utilised in a vacuum cleaner. The force outside of the machine pushes the loose bits of material into the vacuum.
Cylinder vacuum cleaners work by this suction technique. There is an electric motor within, which operates a fan. This fan drives air out of the rear of the vacuum. The force of the atmosphere, propels air up through the cleaning attachment and into the vacuum via the hose. At the same time it pulls up dirt and dust. Before the air exits the rear of the vacuum, the dirt-filled air must pass a dust bag which retains the dirt and dust gathered. Vacuum cleaner models that are upright, contain a rotating brush that beats the dust and dirt out from the carpet, before sucking it into its dust bag.
The state of the art vacuum has multiple attachments, multiple speeds, a guide light and automatic air/carpet freshener capabilities!
