A canister type of vacuum cleaner
houses the suction motor and filtering system in a somewhat square or
rectangular container. Variations of this type are the tank type vacuum
cleaner which has a long tubular main body and the
central vacuum which is mounted on a basement
or garage wall. Typically incorporating a
"clean-air" system, they are known for producing strong
suction for use with the attachments. When
a power nozzle is part of the system it is
often referred to as a power team. A
canister type vacuum cleaner usually contains wheels which allow it to
be pulled after the user by its hose.
Suction Produced by the Standard Canister
The suction motor design in a canister
type 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. To effectively
clean carpeted floors, a power nozzle containing a motor driven
revolving brush should be used to obtain adequate agitation of the carpet
fibers. For more about suction motor and fan designs, see our articles on
Suction Motor Design & Operation and
Fan or Impeller Types &
Performance.
Performance with Attachments
While an upright specializes in cleaning carpets, a canister type
vacuum cleaner specializes in cleaning with its attachments. On-board
attachments on uprights are handy to clean a corner or your
upholstered furniture but are somewhat limited in what they can do
efficiently. A canister type usually has a longer hose, additional
attachments for cleaning floors and more suction when using the
attachments. They are easily pulled around by their hose, something
uprights usually won't do without tipping over. Many canister types carry
their attachments conveniently with them for fast switching from one
to another. Power teams easily compete with uprights when it comes to
effectively cleaning carpeted floors and are generally more versatile
with the attachments.
Air Flow and Filtration Aspects
The air enters the nozzle near the floor and travels through the
wands and hose toward the paper 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. Since the "clean-air" suction motor design creates more
suction (pressure difference) than a traditional upright design, more
filtering can be done without significantly effecting the air flow.
"Clean-air" uprights and canisters can easily have filtration efficiencies
which meet the HEPA specification when
equipped with appropriate filters.
Summary
A canister type vacuum cleaner is very versatile, providing superior
suction for use with the attachments. When it includes a motorized power
nozzle or when teamed with a good upright it will clean all surfaces
effectively. These combinations provide an excellent alternative to using
an upright with on-board attachments.
Next Vacuum Cleaner Type: Hand Held Vacuum Cleaner