Effects of Brushing Action
The beauty, warmth and softness of carpeted floors have made them very
attractive to most people. With carpet comes the challenge of removing the
grit, dirt and dust that somehow find their way deep into the carpet nap.
Over the years vacuum cleaners have advanced to the point that they are
very capable of removing these items and preventing them from being
recirculated back into the living environment. For details on how to
efficiently trap the fine dust and allergens, see our article on Filtration Efficiency - HEPA, ULPA, etc.
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Effectiveness of the Standard Canister |
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A standard canister type of vacuum cleaner
relies primarily on its air flow to pick up
dirt and carry it into the dirt container. This works quite well for
cleaning non-carpeted floors with a floor brush as well as dusting wooden
furniture, cleaning upholstered furniture and catching those small corners
with the smaller attachments. The bristles on a floor brush help to gather
the dirt and grit while keeping the air flow very close to the floor
surface.
Moving air alone is far from adequate when it comes to removing deeply
embedded dirt in carpets since it is nearly impossible to have the air
flow reach the deep dirt with sufficient velocity to motivate it to move
from its place. Most standard carpet nozzles have a stationary brush strip
which aids in the removal of dirt, lint, hair, threads, etc. which are
near the surface of the carpet but this still falls far short of reaching
the dirt near the base of the carpet nap. Grit, with its sharp edges and
corners, is one of the primary causes of carpet wear. The revolving brush
roll was developed to make a huge difference in the effectiveness of a
vacuum cleaner in removing this deeply embedded dirt. Its high speed
brushing action and agitation also fluff the
carpet nap, giving it a fresher, newer look.
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A Revolving Brush Roll Greatly Enhances Carpet Cleaning |
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Vacuum cleaners specifically designed to clean carpeted floors have
motor or turbine driven revolving brush rolls
with rows of bristles and sometimes beater
bars as well. These brush rolls revolve at a very high speed, agitating the carpet fibers in the
process. The effect of this is to loosen dirt and move it toward
the top, aiding in its removal from the carpet fibers. The suction from the motor pulls the
carpet under the nozzle up against it, bowing it backward
slightly. This helps to separate the nap, enhancing the air flow
through it and allowing the bristles to sweep the dirt and grit
upward. When beater bars or stiffened bristles are included on
the brush roll, they tap the carpet back quickly. Due to
inertia, the grit and dirt want to stay stationary as the carpet
moves downward. The combination of the high speed brushing and
beating actions is very effective in moving the dirt and grit
upward in the carpet fibers so the air flow can carry them away.
The aggressiveness of a revolving brush roll goes a long way toward its
ability to deep clean carpets but this can be harmful to some carpets like
Berber and delicate oriental carpets. A number of manufacturers of Berber
carpets do not recommend using a revolving brush roll on them since the
tops of the loops can be damaged. A type of cut Berber instead of looped
Berber has recently become available which has the durability of Berber
but with less risk of damage from a revolving brush roll. We recommend
that you check with the manufacturer or their representative to determine
whether to use a revolving brush on Berber or delicate oriental carpets.
If you choose to use a revolving brush roll, we recommend the Miele SEB
217-3 Powerbrushes which are available for Miele canisters like the
Miele S5280 Callisto,
Miele S5580 Aquarius and
Miele S5980 Capricorn
power team since its long soft bristles are fairly gentle on the carpet
fibers.
The Hoover Company calls their brush roll
an "agitator." They are the inventor of the beater bar which they used for
many years. They even promoted it with the phrase "It Beats as it Sweeps
as it Cleans." After their patent expired, many other companies added
beater bars to their brush rolls. Today most manufacturers have moved away
from the use of a beater bar in favor of two rows of bristles instead of
one row of bristles and a beater bar. A number of companies use stiffener
bars located right behind the brush strips to create a similar beating
effect.
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Revolving Brush Roll Variations |
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Most manufacturers use plastic, acrylic or wooden brush rolls
with the bristles embedded into the roll itself. Some of the
higher quality vacuum cleaners use steel brush rolls with
replaceable brush strips and ball
bearings. Brush rolls come in many shapes and sizes, some
are round, others are contoured or auger shaped. Some have few
bristles and no beater bars, others have many bristles and
beater bars or bristle stiffener bars. Even the speed at which
they rotate varies from model to model, some as high as 6,500
RPM. Don't let the speed of the brush roll mislead you though.
Some of the fastest revolving brush rolls have very few bristles
on them.
Revolving brush rolls are found in all
Traditional Uprights, all "Clean-Air"
Uprights, all Two-Motor Uprights,
all Two-Motor Power Teams as well as some
Hand Held Vacuum Cleaners. The motorized carpet
nozzles on the two-motor power teams and central vacuum systems are
typically called power nozzles. Some
Standard Canisters and
Central Vacuum Systems have turbine nozzles which
have revolving brush rolls driven by turbines instead of motors.
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Motorized Power Nozzles vs. Air Driven Turbine Nozzles |
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To distinguish between the two types of carpet cleaning nozzles with
revolving brush rolls, they are often referred to as a motor driven
power nozzle and an air driven
turbine nozzle. When using a power nozzle,
the electric motor actually adds power to the cleaning system. A turbine
nozzle should not be confused with a motorized power nozzle. When a
turbine is used instead of an electric motor, the power to drive the brush
roll is actually removed from the air flow, reducing the velocity of the
air flow through the system. Both types of nozzles incorporate a
revolving brush roll similar to that used in the upright type of vacuum
cleaner to deep clean the carpets. The better ones use a non-slip cog or
gear type of belt for better power transfer from the motor or turbine to
the brush roll.
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Upholstery Tools with Revolving Brush Rolls |
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Some power teams and central vacuum systems have motorized upholstery
tools which are like miniature power nozzles with their own electric
motors and revolving brush rolls. These are ideal for deep cleaning
upholstery, carpeted stairs, beds, etc. Since the suction is created by a
large canister or central system motor a motorized upholstery tool is more
effective than using a small hand held vacuum cleaner. Having its own
motor to drive the revolving brush, it adds to the power of the cleaner
like the full size power nozzle. Available for use on most
vacuum cleaners are upholstery nozzles with turbine driven revolving brush
rolls like the Miele STB 101 Turbobrush
and generic 0905C and 120 Air Turbine Upholstery Nozzles.
Whether motor driven or turbine driven, these powered brushes can make
a significant difference in the effectiveness of their upholstery nozzles.
By using a motor driven revolving brush roll, carpet cleaning is much,
much more effective than when using a standard carpet nozzle having only a
stationary brush strip. Ease of use is greatly improved as well since the
cleaning nozzle can glide easily across the carpet. The revolving brush
roll even helps to pull the nozzle forward, giving the feel of being
self-propelled on some cleaners. Powered revolving brush rolls are found
in uprights, power teams, central vacuum systems and hand vacs which come
in many different sizes, shapes and prices to fit almost any cleaning
task, preference and budget. See our list of
Ristenbatt Vacuum's Preferred Models for detailed descriptions of a
number of outstanding vacuum cleaners which are featured on our web site.
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