Electric Hoses
A special type of vacuum cleaner hose which has internal wires which carry the electrical current which runs the power nozzle's motor. Often these same wires are used to reinforce the hose but not always as in the case of crushresistant hoses.

Electrostatic Filter
A type of filter media consisting of very fine synthetic fibers on which a static electric charge builds as air passes through them. This charge attracts even the smallest of dust and allergen particles, aiding the filter in retaining them. See also our article on Filtration Efficiency - HEPA, ULPA, etc.

Fan
The fan or impeller is the disk shaped structure with fins that creates the actual suction in a vacuum cleaner. For more information, see our article on Fan or Impeller Types & Performance.

Field
Relative to a vacuum cleaner motor, the field consists of a laminated iron frame on which one or two coils of copper wire are wound. It is shaped so that it wraps around the core of the armature on two opposite sides. The flow of electrical current through the coils creates a magnetic field which interacts with the magnetic fields created by the coils on the armature to cause the armature to rotate. For more information, see our article on Suction Motor Design & Operation.

Filteraire Bags
A special name Eureka gives to their high filtration dustbags. According to Eureka, "The Micron Filter System retains up to 100% of dust mites, grass and ragweed pollen plus particles 15 times smaller than the diameter of a human hair. Filteraire® bags filter 5 times better than standard dust bags." For more information, see Dustbag Performance and Filtration Efficiency.

Filtration Efficiency
The percentage of particles retained by the filter as air passing through it. The size of the particles is typically specified since the filtering efficiency increases as particle size increases. See also our article on Filtration Efficiency - HEPA, ULPA, etc.

Filtration System
The system through which air passes to have particles removed from it. It typically consists of a series of filters made from various filter media. Various components which can be used in filtering systems include paper bags, nylon electrostatic filters, glass fiber paper filters, cloth or foam filters, cyclonic chambers, and even water. See also our article on Filtration Efficiency - HEPA, ULPA, etc.

Flow-Thru Cooled
The suction motor design where the air flow which picked up the dirt travels through both the suction fans and the actual motor itself to cool it. This type of motor can only be used in vacuum cleaners which incorporate the "clean air" design so that very little residual dust is present in the main air flow.

Genuine
When used relative to supplies or parts, this term indicates that the item was manufactured or marketed by the same company that manufactured the product in which it is used. This manufacturer is often called the Original Equipment Manufacturer (OEM). See Genuine vs. Generic Dustbags for the importance of using dustbags marketed by the OEM.

Graduated Filtration
A filtering system wherein each filter in the series of filters is designed to remove particles which are smaller then the previous filter. This enhances air flow and extends the filter media's effective life span. See also our article on Filtration Efficiency - HEPA, ULPA, etc.

HEPA
HEPA (High Efficiency Particulate Air) is a filtering efficiency specification for filters developed by the Atomic Energy Commission during World War II to effectively remove radioactive dust from plant exhausts without redistribution. A HEPA filter must be capable of capturing 99.97% of all particles as small as 0.3µm (micrometers - formerly microns) in size from the air which flows through it. The phrase "as small as" means that if all particles were that small, it would still have that efficiency. This should not be confused with the phrase "down to" which may mean a mixture of particle sizes for the stated efficiency. Please see also "Can HEPA or S-Class Filtered Household Vacuums Safely Retain Anthrax?" for an answer to this important question.
Certified HEPA filters, like those used by Miele and Lindhaus, are tested and marked with a certification number which gives the user the assurance that the HEPA specification efficiency is actually being achived by the filter. The HEPA acronym is used primarilly in the USA whereas Europeans often refer to the same filter as an S-Class filter. This indicates that the filter meets stringent standards like the British Standard 5415 and German norm: DIN 2418B Ti-E EU 13 for filtration performance. See also our article on Filtration Efficiency - HEPA, ULPA, etc.

HEPA Type
A type of filter or paper bag which uses similar construction or fibers to that used in a true HEPA filter. Some are thick filter pads which actually meet the stringent HEPA filtration specification. While being a significant improvement over regular filters, the vacuum that uses it may not have a completely sealed filtration system so there is no guarantee that the stringent HEPA specification will be met by it. Manufacturers who use Certified HEPA filters tend to consider any non-certified HEPA filter to be a "HEPA Type" filter. See also our article on Filtration Efficiency - HEPA, ULPA, etc. Please see also "Can HEPA or S-Class Filtered Household Vacuums Safely Retain Anthrax?" for an answer to this important question.

HEPA Type Bags
A special name Royal gives to their highest filtration dustbags. According to Royal, their HEPA Type dustbag is "Lined with Electrostatically charged fibers. Fine dust and pollen particles are trapped to keep the air returning to your room 99.9% 'Fresh'. Ideal for Allergy Suffers. HEPA is an acronym for High Efficiency Particle Arrestance and describes a special type of extended surface, deep bedded, randomly positioned fibrous material media." HEPA Type dustbags and filters often do not meet the stringent HEPA specification. For more information, see Dustbag Performance and Filtration Efficiency.

Hoover Filtrete?HEPA Bags
A special name Hoover gives to their highest filtration bags. They are constructed with Filtrete?filter media. According to Hoover, this bag "Traps 99.97% of all particles down to 0.3 microns. The Filtrete?HEPA Bag has a triple layer of material that traps many allergens, such as dust mites and their eggs, ragweed and common grass pollens." Filtrete?is trade mark and product by 3M. For more information, see Bag Performance and Filtration Efficiency.

Inertia
The tendency of matter to remain stationary if not moving or to keep moving in the same direction if not stationary. Inertia is what causes the air in a fan to move outward as it spins since it tries to move in a straight line.

IntensiveClean Bags
A special name Miele gives to their high filtration dustbags. Miele states "First and foremost, the unique new material which composes IntensiveClean dustbags has made significant progress in the quality of filtration: Thanks to its intricate web of three-ply random-spun polymer fibers, far more tiny particles and allergens are retained than with conventional paper bags. This alone accounts for a reduction in dust emissions from the dustbag of up to 50%, based on levels which were already extremely low." For more information, see Dustbag Performance and Filtration Efficiency.

Lexan
Lexan is GE's registered trademark for a particular polycarbonate resin. For more information, see our article on External Structure Materials & Durability or General Electric's articles on GE Plastics and Designing with LEXAN Resin.

Load
Relative to a vacuum cleaner, the object (mass) or device to which the power of the electric motor or turbine is delivered. The forces applied by the power of the brush motor or turbine enable the brush roll to revolve, its brushes and beater bars moving the carpet fibers. The forces applied by the power of the suction motor enable the fans to spin, moving the air that is entering them. For more information, see The Load to the Suction Motor in our article on Suction Motor Design & Operation.
Mach
A number representing the ratio of the speed of an object to the speed of sound in the medium throught which it is traveling (ie. - through air). Someone at The Hoover Company got the lofty idea to use "MACH" numbers to represent how many deluxe features are on their various WindTunnel upright models. This rating has nothing to do with power ratings nor cleaning performance since all Hoover WindTunnel uprights are rated at 12 Amps. See also our article on the Power of the Suction Motor.

Magnetic Field
The area near a current-carrying conductor or a magnetic object in which the forces due to the magnetic object or current can be detected. The strength of magnetic fields are increased by wrapping the conductor (typically an enamel insulated wire) around a soft iron object. This is done in the construction of the armatures and fields used in vacuum cleaner motors.

MicroFiltration Bags
A special name Hoover gives to their high filtration dustbags. They are also known as Allergen Filtration dustbags. According to Hoover, this dustbag "Traps 99% of particles down to 5 microns! Filters a wide range of airborne particles including many pollens, spores, other allergens and dust mites. Ideal for many with dust related or allergic discomforts. Electrostatically charged liner enhances the capture of extremely fine particles." For more information, see Dustbag Performance and Filtration Efficiency.

MicroFresh Bags
A special name Royal gives to their high filtration dustbags. According to Royal, these paper bags are "Ideal for allergy suffers. Cleans the air so it's over 99% particle free. Electrostatically charged fibers retain dust and pollen down to 0.1 micron in size." For more information, see Dustbag Performance and Filtration Efficiency.

Micrometer (µm)
A unit of measure equal to 1/1,000,000 meter (10-6 meter). To put this into perspective, the diameter of a human hair is typically 80 to 100 micrometers. According to the National Institute of Standards and Technology (formerly known as the National Bureau of Standards) as stated in their Metric Style Guide this term should be used instead of the obsolete term micron.

Micron
A unit of measure equal to 1/1,000,000 meter (about 1/25,000 inch). To put this into perspective, the diameter of a human hair is typically 80 to 100 microns. While this term is often used for specifying particle sizes for the HEPA and ULPA filtration specifications, it is actually considered obsolete by the National Institute of Standards and Technology (formerly known as the National Bureau of Standards) as stated in their Metric Style Guide. The more proper term for this unit of measure is micrometer (µm).

Micron Bags
A special name Panasonic gives to their high filtration dustbags. According to Panasonic, their bags have a "Total Efficiency of 99.9% at five microns. Can even trap some particles as small as 0.1 microns." For more information, see Dustbag Performance and Filtration Efficiency.

Micron Filter
This type of filter gets its name from its ability to trap micron (micrometer) size particles at a very high efficiency rate. Its filter media consists of very fine synthetic fibers on which a static electric charge builds as air passes through them. This charge attracts even the smallest of dust and allergen particles, aiding the filter in retaining them. See also our article on Filtration Efficiency - HEPA, ULPA, etc.

Milibar (mbar)
A unit of measurement typically used in the USA to report atmospheric pressure. A newer term for millibars used by US scientists and the rest of the world is hectopascals (hPa). You may see the suction of a European vacuum cleaner rated in millibars. To convert from millibars to inches of mercury, multiply it by 0.02953. Since mercury has a specific gravity of 13.546, you then need to multiply the inches of mercury by 13.546 to get inches of water lift. Alternately, you can simply multiply millibars by 0.4 to get inches of water lift.

Motor Brushes
In a vacuum cleaner motor, the motor brushes are carbon rods which are held against the commutator in order to carry the electrical current to the windings on the armature. They are often called "carbon brushes" as well. See also our article on Suction Motor Design & Operation.

Nylon
Nylon is one of the toughest, strongest and most elastic substances. The discovery of nylon in 1935 by Wallace H. Carothers, while working at the E. I. du Pont de Nemours & Company (now Du Pont), is considered one of the most important chemical discoveries in history. See also our article on External Structure Materials & Durability.