A vacuum cleaner (in colloquial British English also hoover) is a device that uses an air pump to create a partial vacuum to suck up dust and dirt, usually from floors. Most homes with carpeted floors in developed countries possess a vacuum cleaner for cleaning. The dirt is collected by a filtering system or a cyclone for later disposal.
McGaffney was but one of many 19th-century inventors in the United States and Europe who devised manual vacuum cleaners. The first patent for an electrically driven "carpet sweeper and dust gatherer" was granted to Corinne Dufour of Savannah, Georgia in December 1900.
Booth started the British Vacuum Cleaner Company and refined his invention over the next several decades. Though his "Goblin" model lost out to competition from Hoover in the household vacuum market, his company successfully turned its focus to the industrial market, building ever-larger models for factories and warehouses. Booth's company lives on today as a unit of pneumatic tube system maker Quirepace Ltd.
Hoover is also notable for an unusual vacuum cleaner, the Hoover Constellation, which is a canister type but lacks wheels. Instead, the vacuum cleaner floats on its exhaust, operating as a hovercraft, although this is not true of the earliest models. They had a swivel top hose with the intention being that the user would place the unit in the center of the room, and work around the cleaner.
Introduced in 1952, they are collectible, and are easily identified by the spherical shape of the canister They tended to be loud, had poor cleaning power, and could not float over carpets. But they remain an interesting machine; restored, they work well in homes with lots of hardwood floors.
The Constellations were changed and updated over the years until discontinued in 1975. These Constellations route all of the exhaust under the vacuum using a different airfoil. The updated design is quiet even by modern standards, particularly on carpet as it muffles the sound. These models float on carpet or bare floor - although on hard flooring, the exhaust air tends to scatter any fluff or debris around.
Hoover has now re-released an updated version of this later model Constellation in the US (model # S3341 in Pearl White and # S3345 in stainless steel). Changes include a HEPA filtration bag, a 12 amp motor, a suction turbine powered rotating brush floor head, and a redesigned version of the handle, which tended to break.
This same model was marketed in the UK under the Maytag brand, with the model being the Satellite. Same machine, different badges, owing to licensing restrictions.
The 5.2 amp motor on older US units provides respectable suction but they all lack a motorized brush head. Therefore they generally work better on hard floors or short pile rugs. Old units take Hoover type J paper bags but the slightly smaller type S allergen filtration bags can be easily trimmed to fit the retaining notches on the old vacuums. Replacement motors are still available from Hoover US for some models.
Hoover made another hovering vacuum cleaner model called the Celebrity in 1973. It has a flattened "flying saucer" shape. Hoover added wheels to it make it a conventional canister model after a brief run as a hovering vacuum. It uses type H bags.
Vacuum cleaners working on the cyclone principle became popular in the 1990s, although some companies (notably Filter Queen and Regina) have been making vacuum cleaners with cyclonic action since 1928. In 1959 Amway patented the first 'bagless' cyclonic vacuum, called the CMS 1000. Modern cyclonic cleaners were adapted from industrial cyclonic separators by British designer James Dyson in 1985. He launched his cyclone cleaner first in Japan in the 1980s at a cost of about US$1,800 and later the Dyson DC01 upright in the UK in 1993 for £200. It was expected that people would not buy a vacuum cleaner at twice the price of a normal cleaner, but it later became the most popular cleaner in the UK.
Cyclonic cleaners do not use bags: instead, the dust collects in a detachable, cylindrical collection vessel. Air and dust are blown at high speed into the collection vessel at a direction tangential to the vessel wall, creating a vortex. The dust particles and other debris move to the outside of the vessel by centrifugal force, where they fall because of gravity, and clean air from the center of the vortex is expelled from the machine after passing through a number of successively finer filters at the top of the container. The first filter is intended to trap particles which could damage the subsequent filters that remove fine dust particles. The filters must regularly be cleaned or replaced to ensure that the machine continues to perform efficiently. Since Dyson, several other companies have introduced cyclone models, including Hoover, and the cheapest models are no more expensive than a conventional cleaner.
In early 2000 several companies developed robotic "vacuum" cleaners. Some examples are Roomba, Robomaxx, Trilobite and FloorBot. These machines propel themselves in patterns across a floor, cleaning surface dust and debris into their dustbin. They usually can navigate around furniture and find their recharging stations. Most robotic "vacuum" cleaners are designed for home use, although there are more capable models for operation in offices, hotels, hospitals, etc. Some such as the Roomba are equipped with an impeller motor to create an actual vacuum. By the end of 2003 about 570,000 units were sold worldwide.
In 2004 a British company released Airider, a hovering vacuum cleaner that floats on a cushion of air. It is claimed to be light weight and easier to maneuver (compared to using wheels), although it is not the first vacuum cleaner to do this - the Hoover Constellation predated it by at least 35 years.
There is a recorded example of a 1930s Electrolux vacuum cleaner surviving in use for over 70 years, finally breaking in 2008.
Tests have shown that vacuuming can kill 100% of young fleas and 96% of adult fleas.
Vacuum cleaner configurations:
The older of the two designs, dirty-fan cleaners have a large impeller (fan) mounted close to the suction opening, through which the dirt passes directly, before being blown into a bag. The motor is often cooled by a separate cooling fan. Due to their large-bladed fans, and comparatively-short airpaths, dirty-air cleaners create a very efficient airflow from a low amount of power, and make great carpet cleaners. Their 'above-floor' cleaning power is less efficient, since the airflow is lost when it passes through a long hose.
Clean-fan uprights have their motor mounted after the bag. Dust is removed from the airstream by the bag, and usually a filter, before it passes through the fan. The fans are smaller, and are usually a combination of several moving and stationary turbines working in sequence to boost power. The motor is cooled by the airstream passing through it. Clean-air vacuums are good for both carpet and above-floor cleaning, since their suction does not significantly diminish over the distance of a hose, as it does in dirty-fan cleaners. However, their air-paths are much less efficient, and can require more than twice as much power than dirty-fan cleaners to achieve the same results.
The most common upright vacuum cleaners use a drive-belt powered by the suction motor to rotate the brush-roll. However, a less common design of dual motor upright, often found in commercial vacuum cleaners, is available. In these cleaners, the suction is provided via a large motor, while the brush-roll is powered by a separate, smaller motor, which does not create any suction. The brush-roll motor can sometimes be switched off, so hard floors can be cleaned without the brush-roll scattering the dirt. It may also have an automatic cut-out feature, which shuts the motor off if the brush-roll becomes jammed, protecting it from damage.
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 switch on the handle of the hose, or the unit powers up when the hose is plugged into the wall inlet. 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 recirculated 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.
Most vacuum cleaners are supplied with various specialized attachments, tools, brushes and extension wands to allow them to reach otherwise inaccessible places or to be used for cleaning a variety of surfaces.
Vacuums by their nature cause dust to become airborne, by exhausting air that is not completely filtered. This can cause health problems since the operator ends up inhaling this dust. There are several methods manufactures are using to solve this problem. Some methods may be combined together in a single vacuum. Typically the filter is positioned so that the incoming air passes through it before it reaches the motor.
The performance of a vacuum cleaner can be measured by several parameters:
The suction is the maximum pressure difference that the pump can create. For example, a typical domestic model has a suction of about negative 20 kPa. This means that it can lower the pressure inside the hose from normal atmospheric pressure (about 100 kPa) by 20 kPa. The higher the suction rating, the more powerful the cleaner. One inch of water is equivalent to about 249 Pa; hence, the typical suction is of water.
The power consumption of a cleaner, in watts, is often the only figure stated. Many North American vacuum manufacturers only give the current in amperes (e.g. "12 amps" ) and the consumer is left to multiply that by the line voltage of 120 volts to get the power ratings in watts. The power does not indicate the effectiveness of the cleaner, only how much electricity it consumes. The amount of this power that is converted into airflow at the end of the cleaning hose is sometimes stated, and is measured in air watts: the units are simply watts; "air" is used to clarify that this is output power, not input electrical power. This is calculated using the formula:
|cleaning power (air watts)||= airflow (CFM) × suction (inches of water) / 8.5|
|= airflow (m³/s) × suction (Pa)|
Some vacuum cleaners include an electric mop in the same machine: for a dry and a later wet clean.