Vacuum cleaner specifications

The performance of a vacuum cleaner can be measured by several parameters:
airflow, in cubic feet per minute (CFM or ft³/min) or litres per second (l/s)
air speed, in miles per hour (mph) or metres per second (m/s)
suction, vacuum, or water lift, in inches of water or pascals (Pa)

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 80 inches 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"[1]) and the consumer is left to multiply that by the line voltage of 120 volts to get the power ratings in volt amperes (not quite the same as watts for AC current, see AC voltages). 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)


Air watts measured at the vacuum's motor can differ by as much as 50% (depending on the type of vacuum) from the air watts measured at the end of the hose. This is most noted in Central Vacuums.

Some smaller vacuum cleaners are light-weight, portable with 1 hand, and rechargeable, instead of using AC power.

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Vacuum Cleaner Configurations

Vacuum cleaner configurations:
Upright vacuum cleaners have the pump mounted directly above the suction intake, with the bag mounted on the handle, which rises to about waist height. Upright designs usually employ mechanical beaters, often rotating brushes, to help disturb dust to be vacuumed up. There are two types of upright vacuums. On a single-motor upright, 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. The dual motor upright is very common in commercial uprights.
Canister (or cylinder) designs have the motor and bag in a separate canister unit (usually mounted on wheels) connected to the vacuum head by a flexible hose. Although upright units have been tested as more effective (mainly because of the beaters), the lighter, more maneuverable heads of canister models are popular. Some upmarket canister models have "power heads", which contain the same sort of mechanical beaters as in upright units, although such beaters are driven by a separate electric motor.
Wet vacs or wet/dry vacuums—a specialized form of the canister vacuum—can be used to clean up wet or liquid spills. They commonly can accommodate both wet and dry soilage; some are also equipped with a switch or exhaust port for reversing the airflow, a useful function for everything from clearing a clogged hose to blowing dust into a corner for easy collection.

Handheld vacuums can vacuum wet and dry. (depending on which vacuum)
Back-pack vacs are commonly used for commercial cleaning: they allow the user to move rapidly about a large area. They are essentially canister vacuum cleaners, except that straps are used to carry the canister unit on the user's back.
Built-in or central vacuum cleaners move the suction motor and bag to a central location in the building and provide vacuum inlets at strategic places throughout the building: only the hose and pickup head need be carried from room to room; and the hose is commonly 8 m (25 ft) long, allowing a large range of movement without changing vacuum inlets. Plastic piping connects the vacuum outlets to the central unit. The vacuum head may either be unpowered 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 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.
Robotic vacuum cleaners move autonomously, usually in a mostly chaotic pattern ('random bounce'). Some come back to a docking station to charge their batteries, and a few are able to empty their dust containers into the dock as well.
Small hand-held vacuum cleaners, either battery-operated or electric, are also popular for cleaning up smaller spills.
Drum vacuums are used in industrial applications. With such a configuration, a vacuum "head" sits atop of an industrial drum, using it as the waste or recovery container. Electric and Compressed Air powered models are common. Compressed air vacuums utilize the venturi effect. Manufacturers include Nortech Corporation and HafcoVac.

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.

History of Vacuum cleaner

A vacuum cleaner is a device that uses an air pump to create a partial vacuum to suck up dust and dirt, usually from carpeted floors, but also from tiled floors and other smooth surfaces. Most homes with carpeted floors in developed countries possess a domestic vacuum cleaner for cleaning. The dirt is collected by a filtering system or a cyclone for later disposal.

History of the Vacuum Cleaner

Ives W. McGaffey


The first manually-powered cleaner using vacuum principles was the "Whirlwind", invented in Chicago in 1869 by Ives W. McGaffey. The machine was lightweight and compact, but was difficult to operate because of the need to turn a hand crank at the same time as pushing it across the floor. McGaffey obtained a patent for his device on June 5, 1869, and enlisted the help of The American Carpet Cleaning Co. of Boston to market it to the public. It was sold for $25, a high price in those days. It is hard to determine how successful the Whirlwind was, as most of them were sold in Chicago and Boston, and it is likely that many were lost in the Great Chicago Fire of 1871. Only two are known to have survived, one of which can be found in the Hoover Historical Center. McGaffey 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.

H. Cecil Booth

The first powered cleaner employing a vacuum was patented and produced by H. Cecil Booth in 1901. He noticed a device used in trains that blew dust off the chairs, and thought it would be much more useful to have one that sucked dust. He tested the idea by laying a handkerchief on the seat of a dinner chair, putting his mouth to the handkerchief, and then trying to suck up as much dust as he could onto the handkerchief. Upon seeing the dust and dirt collected on the underside of the handkerchief he realized the idea could work. Booth created a large device, known as Puffing Billy, driven first by an oil engine, and later by an electric motor. It was drawn by horses and parked outside the building to be cleaned. Booth never achieved great success with his invention.

Walter Griffiths


In 1905 "Griffith's Improved Vacuum Apparatus for Removing Dust from Carpets" was another manually operated cleaner, patented by Walter Griffiths Manufacturer, Birmingham, England. It was portable, easy to store, and powered by "any one person (such as the ordinary domestic servant)", who would have the task of compressing a bellows-like contraption to suck up dust through a removable, flexible pipe, to which a variety of shaped nozzles could be attached. This was arguably the first domestic vacuum-cleaning device to resemble the modern vacuum cleaner.

David T. Kenney


Nine patents granted to the New Jersey inventor David T. Kenney between 1903 and 1913 established the foundation for the American vacuum cleaner industry. Membership in the Vacuum Cleaner Manufacturers' Association, formed in 1919, was limited to licensees under his patents.

James Murray Spangler


In 1906, James Murray Spangler, a janitor in Canton, Ohio, in the United States, invented an electric vacuum cleaner from a fan, a box, and a pillowcase. In addition to suction, Spangler's design incorporated a rotating brush to loosen debris.

Hoover

Spangler patented his rotating-brush design 1908, and eventually sold the idea to his cousin's "Hoover Harness and Leather Goods Factory". In the United States, Hoover remains one of the leading manufacturers of household goods, including cleaners; and Hoover became very wealthy from the invention.

In Britain Hoover has become so associated with vacuum cleaners as to become a genericized trademark. The word "hoover" (without initial capitalization) often is used as a generic term for "vacuum cleaner". Hoover is often used as a verb, as well, as in "I've just hoovered the carpet".


Hoover is also notable for an extremely 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. Introduced in 1952, they are quite collectible today, and are easily identified by the spherical shape of the canister. They tended to be loud, had relatively poor cleaning power, and could not float over carpets. But they remain a very interesting machine; restored, they work well in homes with lots of hardwood floors.

In 1959 an updated Constellation with a stationary handle replaced the previous model and was made until 1980. These Constellations route all of the exhaust under the vacuum using a different airfoil. The updated design is rather quiet even by modern standards particularly on carpet as it muffles the sound. These models float on carpet or bare floor. They are worth more to collectors than the older version.

Hoover is in the process of re-releasing 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 was a beautiful design but tended to break.

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. The most highly collectible colors are pink and turquoise. Replacement motors are still available from Hoover US for some models.

Hoover made another hovering vacuum cleaner model called the Celebrity in the late sixties or early seventies. It has a flatted "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.

Post-World War II


For many years after their introduction, vacuum cleaners remained a luxury item; but after World War II they became common among the rising middle classes. They tend to be more common in Western countries because, in some parts of the world, wall-to-wall carpeting is uncommon and homes have tile or hardwood floors, which are easily swept, wiped, or mopped.

How Vacuum Cleaners Work

When you sip soda through a straw, you are utilizing the simplest of all suction mechanisms. Sucking the soda up causes a pressure drop between the bottom of the straw and the top of the straw. With greater fluid pressure at the bottom than the top, the soda is pushed up to your mouth.

This is the same basic mechanism at work in a vacuum cleaner, though the execution is a bit more complicated. In this article, we'll look inside a vacuum cleaner to find out how it puts suction to work when cleaning up the dust and debris in your house. As we'll see, the standard vacuum cleaner design is exceedingly simple, but it relies on a host of physical principles to clean effectively.

It may look like a complicated machine, but the conventional vacuum cleaner is actually made up of only six essential components:

• An intake port, which may include a variety of cleaning accessories
  
• An exhaust port
  
• An electric motor
  
• A fan
  
• A porous bag
  
• A housing that contains all the other components
  

When you plug the vacuum cleaner in and turn it on, this is what happens:
The electric current operates the motor. The motor is attached to the fan, which has angled blades (like an airplane propeller).
As the fan blades turn, they force air forward, toward the exhaust port (check out How Airplanes Work to find out what causes this).
When air particles are driven forward, the density of particles (and therefore the air pressure) increases in front of the fan and decreases behind the fan.

This pressure drop behind the fan is just like the pressure drop in the straw when you sip from your drink. The pressure level in the area behind the fan drops below the pressure level outside the vacuum cleaner (the ambient air pressure). This creates suction, a partial vacuum, inside the vacuum cleaner. The ambient air pushes itself into the vacuum cleaner through the intake port because the air pressure inside the vacuum cleaner is lower than the pressure outside.

As long as the fan is running and the passageway through the vacuum cleaner remains open, there is a constant stream of air moving through the intake port and out the exhaust port. But how does a flowing stream of air collect the dirt and debris from your carpet? The key principle is friction.

http://home.howstuffworks.com/vacuum-cleaner.htm

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How to Buy a Vacuum Cleaner

Consumers are offered a wide variety of choices in styles and features of new vacuum cleaners. Most brands and models are solidly build and will last several years without maintenance problems. The choice in models comes down to your specific needs and tastes.

Major attributes to consider include:
Type - Make sure you consider what types of surfaces you’ll be cleaning. Your choice of the type of vacuum cleaner will depend on it.
Comfort - Make sure you test drive the vacuum to see how well it handles, and how heavy it is. Is the handle comfortable?
Filtration - If you suffer from allergies, consider a unit with a HEPA (High Efficiency Particular Air) filter.
Attachments - Make sure it has the attachments you need, but don’t pay for those you don’t. For example you don’t need the drapery cleaner if you don’t have curtains.
Noise – Some people place a great deal of importance on noise considerations. To respond to this, some models have insulated materials around the motors.

Types:
Upright versus Canister – Uprights are ideal for cleaning just carpets. Canister are more versatile, but may be more difficult to move around.
Stick/Broom Vacuum – Stick vacuums look like stream-lined uprights. They usually have less power than uprights and canisters and are ideal for people in small apartments.
Handhelds – Handhelds are very small vacuums (usually battery operated) for use in cleaning up specific spots that may be difficult to reach with other vacuums.

Other attributes to consider are listed below.

Attributes:
Motor Power (amps) – Measures the amount of current used by the motor. Higher amps doesn’t necessarily mean more cleaning power. Airflow is a truer test of effectiveness.
Air Flow – Usually measured in cfm (cubic feet per minute)
Filtration System – The level of filtration varies from none (use a bag to collect dust) to sophisticated (filter out pollen and particles less than 100? microns). Units with filtration systems generally cost more, but can be effective in reducing allergen in the home. HEPA filters claim to capture 99.97% of all particles.
Dust Collector – Can be a bag (thick paper) or bagless with a plastic container. Both systems work well.
Construction – Can be plastic or metal. Metal vacuum cleaner are usually more durable.
Cord length – Make sure that the cord is long enough for you to effectively clean one area of you home without having to change outlets.
Brush Agitator (roller brush) – The roller with bristles under the machine that spins when the machine is on. It increased the cleaning effectiveness on carpets.
Edge Cleaner – Some models have vacuum areas that extend to the edge of the bottom of the machine for cleaning tight edges.
Other Tools – Detachable hose, extensions, upholstery brushes, corner cleaners. Some units have caddies to hold all the tools.
Headlights – Some models have lights at the front of the base. Unless you live in a particularly dark home, this feature is more of a novelty than a necessity.


Additional information:

See the "How" tab for more information on how to buy vacuum cleaners.

See the "Where" tab for sources of where to buy vacuum cleaners.

See Consumer Reports for comparisons of different models.

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