Vacuum Glossary

Plain definitions for the terms you see in vacuum specs, reviews, and our own brand pages. 30 entries covering filtration, motor types, brush technology, and vacuum form factors.

• Agitator Industry term for the brush roll, common in commercial vacuum spec sheets.
• AirClean Filter Miele's post-motor filter system. The standard AirClean filter is rated below HEPA; the HEPA AirClean upgrade meets true HEPA specification.
• Allergen Filtration A marketing umbrella term for filtration sufficient to trap common household allergens (dust mites, pet dander, pollen).
• Amperage The electrical current the vacuum draws, measured in amperes. North American residential vacuums max out at 12 amps because most household circuits are 15-amp.
• Bagged Vacuum A vacuum design that collects debris in a disposable paper or synthetic bag. The bag itself is part of the filtration system.
• Bagless Vacuum A vacuum design that collects debris in a removable canister rather than a disposable bag.
• Beater Bar Synonym for brush roll. The mid-century industry term, still used by some manufacturers.
• Brush Roll The rotating cylindrical bar with stiff bristles inside an upright or power head. Spins via belt or direct motor drive.
• Brushless Motor A motor design that uses electronic commutation instead of mechanical brushes. Standard in cordless Dyson V-series and increasingly in plug-in vacuums.
• Canister Vacuum A vacuum design with the motor and dust canister mounted on a wheeled body, connected to a cleaning head via a hose and wand.
• Charcoal Filter A filter impregnated with activated charcoal that absorbs odor molecules in addition to capturing particulate.
• Cordless Vacuum A battery-powered vacuum with no plug-in cord. Battery format is typically lithium-ion 18650 cells.
• Cyclonic Separation A separation method that uses centrifugal force in a cone-shaped chamber to throw dust out of the airstream. Pioneered for vacuums by Dyson.
• Dust Capacity The volume the vacuum's bag or canister holds before emptying or replacement is required. Measured in liters (residential) or quarts (commercial).
• HEPA High Efficiency Particulate Air. The US Department of Energy standard requires 99.97% capture of particles 0.3 microns or larger.
• HEPA-Type A marketing term with no formal standard. HEPA-type, HEPA-equivalent, and HEPA-like filters can capture anywhere from 85% to 99% of 0.3 micron particles.
• MERV Rating Minimum Efficiency Reporting Value, an HVAC industry filter rating from 1 to 20.
• Miele Bag Types Miele uses four bag types for different platforms, color-coded for identification: GN (blue), FJM (red), U (beige), KK (yellow).
• Post-Motor Filter The filter that air passes through after exiting the motor and before exhausting from the vacuum. Captures the fine carbon particulate generated by the motor's brushes.
• Pre-Motor Filter A filter positioned between the dust collection (bag or canister) and the motor itself. Protects the motor windings from fine debris.
• ProTeam Backpack A commercial vacuum design with the motor and dust canister mounted on a harness worn on the user's back. The user holds a wand connected by hose.
• S-Class Filtration A European filtration standard requiring 99.95% capture of 0.3 micron particles. Similar to true HEPA but measured under different lab conditions.
• Sealed System A vacuum whose airflow path is engineered so that every cubic foot of air passes through the filter before exhausting. Joints, hoses, and seals are designed to prevent bypass.
• Stick Vacuum A lightweight upright vacuum, often cordless. Slimmer than full uprights, with smaller dust capacity.
• Suction Power (CFM) Cubic Feet per Minute. The volume of air a vacuum moves per unit time.
• Tandem Air A Riccar and Simplicity proprietary upright design with two airflow paths: one through the carpet via the brush roll, one direct from the surface via the hose.
• ULPA Filter Ultra Low Penetration Air. A filter standard stricter than HEPA, requiring 99.999% capture at 0.12 microns.
• Universal Motor A brushed AC motor design that runs on either AC or DC current. The dominant vacuum motor for the last century.
• Upright Vacuum A vacuum design with the motor, dust collection, and cleaning head all combined in one vertical assembly. The dominant residential format in the US.
• Water Lift A measurement of vacuum suction expressed in inches of water column. Measures sealed-suction strength, distinct from airflow (CFM).