When shopping for an air purifier, you may encounter terms you are unfamiliar with. We have created this air purifier glossary to help you understand these terms so that you can make an informed decision on which air purifier will best fit the needs of you and your family.
AIRBORNE PARTICLES
Airborne particles are small bits of dust or dirt that have entered the air. They are a form of air pollution.
AIR POLLUTION
Air pollution is contamination of the air by dust, dirt, chemicals, or other airborne matter.
AIR PURIFIER
An air purifier is a device that uses mechanical filtration and/or other means to reduce airborne particles and pollution. Many air purifiers have only one stage, while others use a stage filter process for greater effectiveness.
AIR FLOW RATE
The air flow rate of an air purifier refers to the amount of air that passes through the unit in a given amount of time. It is usually measured in cubic feet per minute, or CFM.
ALLERGEN
Allergens are substances that trigger an acute defensive reaction in the body's immune system. Common household allergens include smoke, pollen, and pet dander.
ANTI-GERM LIGHT
See UV light.
BACTERIA
Bacteria are single-celled microscopic organisms. They can travel through the air where they can be breathed in.
CARBON FILTER
Carbon has properties that allow it to absorb pollutants such as odors and gases. In a high quality air purifier, a carbon filter is usually used as part of a stage filter process.
CADR RATING
Clean Air Delivery Rates are provided to allow comparison between different products. The CADR measures the volume of filtered air delivered by an air cleaner for a specific pollutant in cubic feet per minute. The air pollutants tested include dust, pollen, and smoke. The CADR ratings are impartial with a standardized testing procedure. The ratings are recognized by the Environmental Protection Agency and The American Lung Association.
CFM
Cubic Feet per Minute. In an air purifier, CFM describes how many cubic feet of air the unit can clean in one minute. See air flow rate.
COLD CATALYST FILTER
A cold catalyst filter helps break down carbon monoxide and other harmful gasses.
DANDER (PET)
Small flakes of dead skin are called dander. Pet dander becomes airborne and we breathe it in. It can cause allergic reactions in some people.
DUST
Very small, dry particles of matter are called dust. Common household dust consists of dander, fibers from clothing, dust mites, and more. There are many sources of dust in our homes including upholstery, clothing, bedding, and pets.
ELECTROSTATIC PLASMA FILTER
This type of air purifier filter uses an electrical charge to cause pollutants to collect on its metal surface.
EPA
Environmental Protection Agency. Established in 1970, the EPA is the United States federal agency responsible for regulating environmental hazards.
HEPA
High Efficiency Particulate Air. Developed by the U.S. government, HEPA filters clean the air by trapping airborne particles down to 0.3 microns in size at an efficiency of 99.97%. This means that for every 10,000 particles, only 3 would make it through a HEPA filter.
INDOOR AIR POLLUTION
Our homes contain many types of air pollution, including dust, dander, and VOCs. The EPA has ranked indoor air pollution as a top environmental public health risk.
IONIZER
An ionizer uses electricity at high voltage to produce electrons, which combine with air molecules to form negative ions. These negative ions are attracted to positively-charged airborne particles, and as they merge, the resulting weight increase causes them to fall out of the air (a process known as agglomeration).
LED
Light Emitting Diode. LEDs are very efficient, bright, and long-lasting lights used in electronic devices. In an air purifier, LEDs are often used to indicate when the filter needs changing. See Replace Filter Indicator.
MICRON
A micron is a unit of length. One micron is equal to 39 millionths of an inch. An average grain of salt is about 60 microns, and particles much smaller than 40 microns are considered invisible to the naked eye.
NEGATIVE ION
A negative ion, in the context of air purifiers, is an oxygen molecule that has a negative charge due to the addition of an extra electron. Ionizers emit clouds of electrons that form negative ions when they collide with oxygen molecules in the air.
PRE-FILTER
To extend the usable life of the main filter(s) and increase efficiency, a quality air purifier may include a pre-filter. The pre-filter is designed to capture larger particles before the air reaches the main air purifier stages. See Stage Filter Process.
REPLACE FILTER INDICATOR
When your air purifier's filter becomes saturated with dust, it can no longer efficiently remove pollution from the air. On a quality air purifier, the Replace Filter Indicator lets you know when the filter needs to be replaced.
STAGE FILTER PROCESS
Many air purifiers rely on only one filtration method to clean the air. Higher quality models use multiple techniques in a “stage filter process” that helps clean the air more effectively. These may include HEPA filters, carbon filters, UV light, photo catalyst filters, cold catalyst filters, ionization, and other methods.
UV LIGHT
Ultraviolet light. UV is invisible to the human eye and is sometimes used in air purifiers to help kill bacteria, viruses, and other pathogens.
VOCs
Volatile Organic Compound. A VOC is a substance that has a low water solubility and a high vapor pressure. Many VOCs are chemicals used or produced for industrial purposes. VOCs make their way into our homes and are a significant source of air pollution. Quality air purifiers reduce VOCs as well as other contaminant.
Return to Articles, Tips & Information Page