The vacuum (also known as a Hoover) is an appliance which uses an air pump in order to create a partial vacuum that in effect sucks up dust and dirt (usually from carpeted floors), but can also be used on tiled floors or other smooth surfaces. Almost every home in developed countries has a vacuum cleaner to help keep the home clean and tidy. All the dirt is gathered by a filtering system or a cyclone for later disposal.
How it works
The suction from a vacuum is caused by the difference in air pressure. A pump is used to reduce the pressure inside the tube. Atmospheric pressure pushes the air through the carpet and into the tube, and so the dust is literally pushed into the bag.
Vacuum cleaner configurations
Upright vacuum cleaners - these vacuum cleaners have the pump mounted directly above the suction intake and a collection bag mounted on the handle, which rises to about waist height. Upright vacuums usually a system of mechanical beaters, which are often rotating brushes that help disturb dust to be vacuumed up. There are two types of upright vacuums, which are:
- Single-motor uprights, the beater brush is driven by the vacuum motor via belt, while on a dual motor upright, the vacuum and beater brush are driven by separate motors.
- Dual motor uprights, these are very common in commercial uprights.
Canister (or cylinder) - These designs house the motor and the bag in a separate unit (usually mounted on wheels) and is connected to the vacuum head with a flexible hose. Even though upright units have a reputation for being more effective (mainly because of the beaters), the lighter, more manoeuvrable heads of the canister models make them very popular. Some of the more expensive canister models have "power heads", which incorporate the same type of mechanical beaters as upright units, although such beaters are driven by a separate electric motor.
Back-pack Vacs - these are commonly used for commercial cleaning jobs. They allow the cleaner to be able to move more rapidly about a large area. They are essentially canister vacuum cleaners, except with straps that are used to secure the canister unit firmly on the cleaners back.
Built-in or central vacuum cleaners - have a suction motor and bag in a central location in the building and provide vacuum inlets in various strategic places around the building. This method is used in high rise buildings and means that the cleaner will only have to carry the hose and pickup head from room to room. The hose is commonly 8 m (25 ft) long, allowing a large range of movement without need to change the vacuum inlet. Plastic piping connects the vacuum outlets to the central unit. The vacuum head may either be un-powered or have beaters operated by an electric motor or air-driven motor. The dirt bag in a central vacuum system is usually so large that emptying or changing needs to be done less often, perhaps once per year. The central unit usually stays in "stand-by", and is turned on by a flick on the handle of the hose. Such a unit also produces greater suction than common vacuum cleaners, because a larger fan and more powerful motor can be used when they are not required to be portable. Another benefit of a central vacuum system is that unlike a standard vacuum cleaner, which blows some of the dirt collected back into the room being cleaned (no matter how efficient its filtration), a central vacuum removes all the dirt collected to the central unit. Since this central unit is usually located outside the living area, no dust is re-circulated back into the room being cleaned. In addition, because of the remote location of the motor unit, there is less noise in the room being cleaned than with a standard vacuum cleaner.