Identifying Good Performance Factors
Like many other household appliances, a vacuum cleaner is designed to
enable its user to more easily and effectively perform specific tasks. A
vacuum cleaner uses air flow, often
combined with brushing action, to pick up
various dirt, dust, allergens, etc. Not only does it need to be efficient
in picking up these objects, but it must also be efficient in removing
them from the air so they are not recirculated back into the living
environment. Since many manufacturers do not publish performance related
specifications, it is often difficult to determine which vacuum cleaner
will actually be the best performer in you specific situation.
The performance of the filtration system is affected by the efficiency
of the paper bag and additional filters as well as the cleaner's ability
to ensure that all the air actually passes through every filter. The
ability of a vacuum cleaner to deep clean carpeted floors is affected
primarily by three factors, the design of the nozzle, the velocity of the
moving air in the nozzle and the agitation
of the carpet fibers by a revolving brush
roll. There are many factors which affect the filtration efficiency
and cleaning efficiency as described below and in related articles. The
durability of vacuum cleaners is discussed in our article titled
"Identifying Durable Designs & Construction."
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Filtration Efficiency - ULPA, HEPA, Micron, etc. |
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The current cutting edge in vacuum cleaner technology is in
the area of improving the filtration efficiencies of vacuum
cleaners. The vacuum cleaner industry is taking advantage of the
development of advanced filtration media to provide much higher
quality exhausted air than was available just a few years ago.
Where there are special dust related sensitivities like allergies
and asthma, vacuum cleaners which have extremely high filtration
efficiencies that meet the HEPA
specifications are often very helpful. It is very important to have
a completely sealed system from input to exhaust so all air flow must
pass through the HEPA filter to be cleaned by it.
Examples of canisters and power teams with HEPA filters in completely
sealed systems are the
Miele S4210 Sirius,
Miele S514i Solaris Electro Plus,
Sanitaire SP7025A Precision and
Sanitaire SP6952A System_Pro.
Examples of uprights with a HEPA filters in completely sealed systems
are the Lindhaus HEALTHCAREpro HEPA and
Miele Universal and Powerhouse uprights.
All SEBO Uprights
utilize a series of very effective filters
in completely sealed systems to create net filtration which meets the
stringent HEPA specification. Some cleaners like the Panasonic and Sharp uprights have
HEPA Type filtration which is better
than standard filtration but does not meet the stringent HEPA filtration
specification.
For more information on factors affecting filtration
efficiency, see our articles on
Filtration Efficiency - HEPA, ULPA, etc. and the
Efficiency of Paper Bags.
When it comes to cleaning performance, there is a tendency to look
primarily at the power of the suction motor and the amount of bristles on
the brush roll. While these are important considerations, the quality and
size of the paper bag are very important factors as well. The quality of
the bag's filter media affects both its ability to retain the fine dust
and allergens and its ability to allow air to easily flow through it. A
good quality paper bag is a very important vacuum cleaner component. Care
should be taken to always replace it with an equally high quality paper
bag so good vacuum cleaner performance is maintained.
Since Ristenbatt Vacuum Cleaner Service understands how very important
it is to use good quality paper bags, we recommend those distributed by
the Original Equipment Manufacturer (OEM or Genuine) of the vacuum cleaner
for maximum performance and minimum problems. To learn more about paper
bag performance, see our article titled "Efficiency
of Paper Bags."
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Identifying Factors Which Affect Air Flow |
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The air flow, combined with
agitation, is one of the most important
aspects of picking up dirt with a vacuum cleaner. It is the force exerted
by the moving air which actually picks up the dirt and moves it into the
bag or dirt container. The motivating factor for the air flow is the
suction created by the
fan in the suction
motor. The limiting factor is the total
resistance to air flow throughout the vacuum
cleaner. Ideally, you want to have the highest possible velocity of air
flow in the area of the nozzle where the dirt is being picked up.
Air flow is rated in cubic feet per minute (CFM). When you see air flow
ratings, the measurement is often taken at the inlet of the vacuum
cleaner. As such, it is always measured with a completely clean
filtration system so the internal resistance is at its absolute minimum.
Unfortunately, this measurement does not accurately reflect what the
actual air flow velocity in the cleaning nozzle will be in typical
cleaning situations. Factors like the amount of
suction developed by the suction motor, the
amount of resistance in the filtration
system as it traps the dirt, the total amount of resistance in all air
passages as well as the design of the cleaning nozzle will significantly
affect the vacuum cleaner's ability to pick up the dirt.
For a more detailed presentation about the factors which affect air
flow, see our article on Air Flow through the
System.
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Suction Motor and Fan Performance |
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The suction motor is one of the most important parts of a vacuum
cleaner. It is this motor which takes the electrical power from the power
source and converts it into mechanical power in the form of suction with air
flow. Rating the motor for its ability to produce suction with air
flow is one of the most misrepresented and misunderstood aspects of vacuum
cleaner technology. This confusion has been accentuated by many
manufacturers in their attempt to make their products appear superior to
others. Various methods of rating the suction motor's performance are
discussed in our article on the Power of the
Suction Motor. For more about the physical design of suction motors,
see our articles on Suction Motor Design &
Operation.
There are two basic vacuum cleaner fan designs. The first type is
used in the traditional upright and some
hand held vacuum cleaner designs while
the other type is used in all other designs including the
"clean-air" upright,
two-motor upright,
two-motor power team,
standard canister and
central vacuum system. For more about these
two types of fans, read our article on Fan or
Impeller Types & Perfomance.
Traditionally the most suction
is created by motors containing at least two fan stages pulling in series.
In an effort to keep vacuum cleaner prices as competitive as possible,
many manufacturers of "clean-air" uprights, canisters and power teams have
switched from using the more efficient two fan motors to using less
expensive one fan motors. This is particularly true of most models found
in department stores and mass merchants. Some newer high performance motor
designs incorporate one fan which is much thicker near its center so more
air can enter its blades. An example of this is the
Miele Vortex Motor and the motor used in the
SEBO canisters.
Lindhaus and
SEBO uprights still
have two fan motors as does the Miele S184 Powerhouse
upright.
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Cleaning Nozzle Design Considerations |
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The design of the cleaning nozzle can have a significant effect on a
vacuum cleaner's ability to clean effectively. It is the force exerted by
the air flow combined with agitation, that actually picks up the dirt at
the cleaning nozzle. The higher the velocity of the air flow close to the
surface being cleaned, the better the cleaning performance will be. The
smaller the area through which the air flow is passing, the greater the
velocity will be. For this reason most nozzles, especially carpet
nozzles without revolving brush rolls, have fairly narrow openings across
their full width. To remove dirt and grit embedded deep within a carpet is
virtually impossible using air flow alone so uprights and power nozzles
with revolving brush rolls were developed.
The air flow velocity should be similar across the full width of the
nozzle so all areas are cleaned well. Most cleaning attachments have
funnel shaped air passages which lead to centered hose or wand connectors.
Uprights which use a similar design for outstanding performance are the
Lindhaus upright, Commercial and Heavy
Duty Sanitaire (by Eureka) uprights,
Commercial and Heavy Duty Royal
uprights and Kirby uprights. Most power nozzles
used on power teams have center mounted air inlets
so air flow is fairly uniform across their full width as well.
Unfortunately, many uprights with on-board attachments have brush roll
housings with the air inlets very close to one of their sides so the air
flow velocity is significantly greater on that side compared to the
opposite side. The Hoover Company recently
developed the WindTunnel Upright series which
incorporates an innovative brush roll housing design which overcomes this
negative effect to a great extent. For a more detailed description of
various nozzle designs and how they affect performance, see our article on
Cleaning Nozzle Design Considerations.
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Enhanced Cleaning with Revolving Brush Rolls |
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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. 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.
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.
By using a motor driven revolving brush roll, carpet cleaning is much,
much better than using a standard carpet nozzle having only a stationary
brush strip. Ease of use is greatly improved as well. 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. For more
about the use of revolving brush rolls, see our article on the
Effects of Brushing Action.
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
217-2 Powerbrushes which are available with Miele canisters
like the Miele S514i Solaris Electro Plus
power team since their long soft bristles are fairly gentle on the carpet
fibers.
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Compromises with Modern Upright Designs |
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Today's modern upright designs are quite different from the traditional upright design used for many
years. The vacuum cleaner industry has developed it to the extent that it
has become like the Swiss Army Knife, being able to tackle almost any
cleaning task. They have added on-board attachments, reduced the weight,
added more bristles to the brush roll and
increased the motor power substantially. Most uprights made today have
motors which are rated between 7 and 12
amps. The Oreck 8 lb. upright is an
exception worth noting since it only has a 4 amp. motor. Perhaps this
should be expected for its light weight, but for its price, the customer
deserves much more. The maximum amperage
permitted for UL Approval of an upright vacuum cleaner is 12.0 Amps. If
you see a rating higher than that, it probably is an Efficiency Rating.
By trying to combine the ability to do all cleaning task into one cleaner,
the industry has made quite a few design compromises. While the motor is
quite powerful, the fan is often a fairly small diameter so its efficiency
is reduced. At the same time, the air passage leading from the main
cleaning nozzle is typically located near one side so the
air flow isn't very uniform across the full
cleaning width. On-board attachments are quite convenient for quickly
cleaning your furniture or a corner here or there but hose lengths are
often too short and cleaning bare floors with them is very inconvenient, if
not almost impossible.
A number of manufacturers are now stating that their
upright cleaners can be used to clean bare floors with the main nozzle
but few, if any, will do really well on non-carpeted floors. Some modern
uprights, like the Hoover U6436-900 have the ability to stop
the brush roll for cleaning bare floors and use with the attachments. This
is beneficial in preventing the dirt and grit from being whipped back
before the air flow can pick it up. Better yet is the option like on the Lindhaus HEALTHCAREpro HEPA to replace the main
nozzle with a floor brush and snap-on felt pad.
Since the motors are quite powerful on most modern uprights, they are
able to clean quite well on carpets. Be careful to avoid the impression
that they will do as well on bare floors or that they are convenient for
cleaning large areas with the attachments. Some manufacturers are still
making heavy duty traditional uprights like the Royal
metal uprights and Sanitaire S677A Heavy Duty
uprights. These will often perform better than the modern upright designs
for cleaning carpet and can easily be teamed with a compact canister to
efficiently clean everything else.
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Factors Effecting the Loss of Performance with Use |
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While purchasing a vacuum cleaner with sufficient power for its
cleaning task is important, so is selecting one which is designed to
perform well with minimal loss of performance with use. The vacuum
cleaners being used in most homes today are not performing to their best
ability. The three major causes of reduced performance are reduced air
flow through the filtration system, stretched and slipping belts and worn
or soft bristles.
Take a close look at the size of the paper bag and any filter media
through which the air travels. The larger the media area, the less resistance to air
flow will be experienced as the bag fills and as filters become
soiled. High efficiency filters which meet the stringent HEPA or ULPA
filtration specification have extremely large areas so they are fan folded
into cartridges small enough to fit into the cleaners. It is important to
have a number of prefilters before the HEPA or ULPA filter to prevent them
from becoming soiled rapidly, requiring frequent replacement. One of the
best filtration systems is in the Nilfisk GD 90C
Certified ULPA Allergy Vacuum with its large bag and extra large
filters in a graduated filtration system.
To obtain the best performance with the least problems, use supplies make
by the manufacturer of your vacuum cleaner. They are well worth the
additional cost. Most uprights and power nozzles use a flat stretch type rubber belt to
transfer the power from the motor to the revolving brush roll. Since these
will gradually stretch and slip more as time goes by, they should be
replaced at least once a year to maintain good performance.
Some of cleaners have non-slip cog type belts including all
Lindhaus uprights and
power teams, all SEBO uprights,
all Aerus (formerly Electrolux) uprights
and power teams, all Hayden central
vacuum systems, and the more deluxe Panasonic and
Royal power teams. This
superior design eliminates belt slippage for better carpet
agitation and extends the belt life to about
five to seven years. Cog or gear type belts typically are more narrow so
less space on the brush roll is used by the belt, providing more room for
the bristles.
Bristles, especially on revolving brush
rolls, wear shorter and become softer with use. These should be
replaced about every five years to keep good performance. Some brush rolls
have the bristle secured into wooden or acrylic brush rolls while others
are steel with replaceable brush strips. The cost of replacing bristles in
the latter type is often less expensive than replacing the complete brush
roll. Well designed brush roll bearings and mounts are important,
expecially with plastic or acrylic brush rolls, since bearing failure can
easily cause the roll to melt and require replacement. Lower priced vacuum
cleaners often have poor roll bearing designs and acrylic rolls which
require more frequent replacement.
By looking for good designs in the vacuum cleaner system and performing
a few minor maintenance tasks, your new vacuum cleaner can operate near
its peak performance over its entire life span. For more detailed
information about factors which reduce cleaning performance, see our
article on Loss of Performance with Use.
As you can see from the above, determining which vacuum cleaners will
perform the best for your particular cleaning needs can be a difficult and
complex task. There is a lot more to consider than just the amperage,
suction (water lift) or air flow ratings when comparing vacuum cleaners.
By shopping at a vacuum cleaner specialty store like Ristenbatt Vacuum
Cleaner Service, knowledgeable salespeople can show a broader range of
vacuum cleaners to you including those which are designed to have
outstanding performance in both cleaning and filtration. Your chances of
making the best purchase for your particular cleaning needs is greatly
increased when you talk face to face or on the phone with our
salespeople. All of them are also skilled technicians who are very
knowledgeable about vacuum cleaners, both inside and out. They will be
happy to talk with you regarding your various vacuum cleaner needs,
preferences and desires.
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