You need to have the fewest particles released or driven into the air - regardless of whether that vacuum is HEPA or not. Some microfiltered systems accomplish this just as well as some systems called HEPA. Find out what the "particles out" are, and you'll have the all-important information you need.

Keep in mind that even high-end HEPA-filtered vacuums may still be driving dust airborne by the impact of a beater brush against the carpet. With uprights or canisters equipped with power heads, the critical information to have is how much airflow and lift are occurring at the beater brush / floor interface to help determine whether or not particles are being pulled into the vacuum or driven airborne. The extra-wide orifice on some upright vacuums and power nozzles results in greatly diminished suction at the tool head and poor soil capture. More on this later under "The Venturi Principle".

Myth #3: Picking Up a "Bowling Ball" Shows Cleaning Power
The bowling ball trick is just that - a trick. This sales technique is based on the power of a suction cup. Have you ever stuck a suction cup on a mirror and tried to remove it by pulling directly away from the mirror? It's hard to do. Why? Once a seal is created on a smooth surface, the seal is difficult to break. Does a vacuum tool's ability to form a seal around a bowling ball and pick it up like a suction cup have anything to do with how well the vacuum can remove soil from a surface? No!

Myth #4: All Vacuum Bags are the Same
Again, not true. Multi-ply microfilters greatly increase vacuum efficiency over generic single-ply paper filters. For this reason, microfilters are now increasingly used in commercial vacuuming applications. Microfilter bags have greater media density and thus capture far more fine dust. One-ply generic bags have relatively large pores that permit fine dust to escape, lowering indoor air quality, increasing health risks and the need for dusting.

Also, filter bag size does matter. The greater the "area" of the filter media, the longer airflow, suction and cleaning can be sustained. For this reason, at least one major manufacturer of vacuum cleaners promotes its filters by measuring and publishing the total area - in square inches or centimeters - of its filter bag media.

Myth #5: All Vacuum Belts are the Same
Not all vacuum belts are created equal. A cheap vacuum belt will stretch, slip and wear out quickly, whereas a high-quality belt is geared or sprocketed like an automobile timing belt, and can literally last for years. In addition, geared/sprocketed belts do not slip, ensuring better and more consistent soil pickup and removal. Sprocketed belts help ensure better overall performance, and enable you to spend more time cleaning and less time changing belts.

Myth #6: Cyclonic Systems Do Not Use Filters & Require Less Maintenance
Virtually all cyclonic or bagless vacuuming systems use a final filter to catch the dust that cyclonic filtration cannot remove from the airflow. This is often a HEPA media filter. This final filter will require regular cleaning or replacement to ensure optimal performance. If you fail to perform the needed filter maintenance, the vacuum will not perform as intended. The cost of replacing the final filter may equal or exceed the cost of using conventional bag filter media. The quality of cyclonic systems varies widely. Do your homework and request the all-important "particles in, particles out" information in the form of test data from the manufacturer to determine overall performance.

Some vacuum cleaners are actually designed to produce cyclonic airflow even with conventional microfilters. Ribbed panels in the filter containment area create a rotating column of air inside the filter bag so soil is deposited evenly on the sidewalls of the filter where it has the greatest surface area, ensuring sustained airflow longer.

Myth #7: All Vacuum Cleaners Have Similar Design Features and are Equally Easy to Use
Ergonomic design, weight and other factors affecting ease of use vary widely among vacuum cleaners. Handle weight is a critical factor with uprights, as is ease of rolling and maneuverability.

Canister vacuums vary widely in shape and design affecting usability. One model balances the weight primarily over the large rear wheels to facilitate nimble handling and ease of pulling. Some canisters trip over power cords, while others roll over such obstacles easily. Design and weight distribution makes the difference.

Backpack vacuums now weigh in at less than 10 pounds, with precision suspension systems that distribute the weight across the hips and not the shoulders for ideal balance and maneuverability. One manufacturer produces a backpack vacuum station that enables the operator to simply back into the "port" and slip on the backpack without lifting it.

Myth #8: Suction Alone Makes a Vacuum Work Well
Actually, it's the entire vacuum system that makes it effective - or not. There are four key benchmarks to use in evaluating a vacuuming system:

A) Airflow
Airflow is the amount or volume of air moving through the vacuum, usually measured in cubic feet per minute (CFM). The amount of air moving through a vacuum affects the amount of soil that can be carried along by the airflow and contained in the vacuum's filtration.

B) Lift
Lift, also known as static lift or water lift, is the ability of the vacuum's airflow to lift dirt. It is typically measured in "inches of lift" determined by how many inches the vacuum cleaner's airflow can pull water up a tube in a lab test.

The higher the two numbers - airflow and lift - are, the better, since this combination largely determines the vacuum's ability to pull "particles in".

C) Filtration
Filtration captures the soils and is mainly responsible for reducing "particles out". Filtration must be designed and proportioned to work with the vacuum's airflow and lift so that the particles are stopped but not the airflow.

D) Design
In some cases, good vacuuming potential and/or filtration are defeated by poor design. Examples of poor design include a tool orifice that lowers air velocity by being too wide (many beater brushes require an excessively wide tool orifice that reduces suction significantly) and body tolerances that allow dust to leak from non-filter areas.

The Venturi Principle
The Venturi Principle is an important bit of science to understand. Basically, the Venturi Principle causes air velocity to increase as the corridor it passes through narrows. That explains the effectiveness of suction-only backpacks that use a narrow tool opening or orifice enabling greater suction, versus some upright machines that have a very wide tool orifice to accommodate the rotating brush, thus reducing air velocity and cleaning effectiveness.

The best uprights reach an effective compromise, enabling effective cleaning of plush carpet by proportioning the orifice opening and beater brush to allow the rotating brush to perform well while maintaining proper airflow and lift to remove soil and prevent its being driven airborne.

About the Author
Allen P. Rathey is President of The Housekeeping Channel. The Housekeeping Channel's goal is to be the Web's most comprehensive storehouse of information and resources to help households everywhere achieve a cleaner, more organized and healthier indoor environment. The site provides how-to tutorials, plus news and reviews regarding the latest innovations from the cleaning products industry to improve the home environment. Resources include time-saving systems, tools and motivation for keeping a better house at the click of a mouse.

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