Two-Motor Upright Design & Benefits
An upright type of vacuum cleaner is
a self-contained unit which has the motor,
main cleaning nozzle, filtering system, etc.
all built together in an overall vertical shape. All upright types today
have motor driven revolving brush rolls and
are used primarily for cleaning carpeted floors. They are pushed forward
and pulled backward in front of the user by gripping the narrow handle
extending upward from the main case.
The general upright type can be subdivided into three basic types
having three unique design characteristics. They are the
Traditional Upright, the
"Clean-Air" Upright and the Two-Motor Upright.
The latter is a fairly new arrival in the vacuum cleaner industry.
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Main Characteristics of the Two-Motor Upright |
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The two-motor upright combines a canister
type motor and filtration system in the main body with a
power nozzle type nozzle for cleaning carpeted
floors. Some, like the Lindhaus HEALTHCAREpro HEPA,
are designed to allow the user to remove the main carpet
cleaning nozzle and insert a floor brush to better clean bare floors. The
basic vertical configuration of the upright is maintained while its
versatility is increased. Many uprights having this design conveniently
carry the attachments on-board with the hose always attached and ready to
use. Most, if not all, two-motor uprights give the user the option of
stopping the brush roll for cleaning bare floors or when cleaning with the
attachments. Since the brush roll is driven by its own motor, if its
rotation slows in thicker carpet, the suction produced by the suction
motor is not affected like it would be in a one-motor upright.
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Similarities with "Clean-Air" Uprights |
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Two-motor uprights are also "clean-air" uprights since the air which
passes through the suction producing fan
or fans is already "clean", having passed through most of the
filtering system before reaching it. While
two-motor uprights fit this description, the "clean-air" designation
typically is used to refer to an upright using only one motor to create the
suction and drive the brush roll. As such, it is often used when comparing
"clean-air" uprights to "dirty-air" (traditional) uprights.
The air enters the nozzle near the floor and travels toward the paper
or cloth filter bag, carrying the dirt with it. The bag retains most of
the dirt and dust while allowing the air to pass through its filter media.
The air then travels through a filter pad to be cleaned further before
entering the high speed suction fan or fans. Since the air is quite
clean, it is allowed to flow through the
motor to cool it. After leaving the motor the air is often filtered by
additional exhaust filters to remove even more fine particles and carbon
from the motor brushes before it leaves the
vacuum cleaner.
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Effects on Cleaning Performance |
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Depending on the brand, you may find very little difference between
the performance of a "two-motor" upright and the one-motor "clean-air"
upright. Some "two-motor" uprights, like the Lindhaus,
SEBO,
Electrolux (formerly The Eureka Company) and
Aerus
use cogged or geared type belts to transfer
power from the brush motors to the
brush rolls. This superior design eliminates belt slippage for better
carpet agitation and greatly extends the
belt life. Another feature that enhances the carpet cleaning ability is
the way that the air inlet in the nozzle is either centered or very close
to the center of the nozzle. This provides more consistent air flow and
cleaning across the full width of the nozzle.
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Performance with Attachments |
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The canister motor design creates significantly more actual
suction (pressure difference) than the
traditional upright motor design. This is important for effective cleaning
with a hose and attachments due to the higher
resistance to air flow present in the hose. The velocity of the
air flow plus the amount of the carpet
agitation determines how well a vacuum
cleaner will pick up the dirt so the shorter the distance the air travels
and the larger the air passages, the better the performance will be. Some
uprights pull all the air through a long hose even when cleaning with
the main carpet nozzle, reducing their performance. For more about
suction motor and fan designs, see our articles on
Suction Motor Design & Operation and
Fan or Impeller Types & Performance.
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Increased Motor Protection |
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In addition to better performance with attachments, the "two-motor"
upright tends to have a significantly better track record than many
"dirty-air" uprights when it comes to fan and motor problems. The
manufacturers of "dirty air" uprights with on-board attachments often
use a high speed, small diameter fan to help overcome the lower suction
produced by that design. This often can have the adverse effect of
unusually high fan breakage rates and motor failures, especially when
the motor's amperage is higher than
about nine amps.
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Examples of Efficient Two-Motor Uprights |
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Only a few companies are manufacturing uprights with the "two-motor"
design that are sold in the U.S.A. Some examples of this type of upright
are the Lindhaus HEALTHCAREpro
HEPA, Lindhaus Diamante and Dynamic uprights, SEBO 370 Electronic uprights
and all uprights made by the Aerus (formerly the Electrolux Corporation).
Most of these are not
permitted to be promoted nor sold via the Web.
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Identifying Two-Motor Uprights |
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In summary, "two-motor" as well as other "clean-air" uprights typically
produce better performance when using on-board attachments. They also
have significantly longer fan and motor lives compared to most "dirty-air"
uprights with on-board attachments. Operating noise levels are typically
much lower than from their "dirty-air" counterparts. Having a separate motor
drive the brush roll, some using a cogged or geared type of belt,
can enhance the carpet cleaning ability of "clean-air" uprights.
The two-motor design is hard to identify on some models since they look so
similar to the one-motor "clean-air" uprights. Other models have a
more narrow connector between the main body and carpet cleaning nozzle,
making them easier to identify. Most will be identified as having two
motors somewhere on the cleaner or its literature.
PageType: Educational
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