Air Purifier Standards, Ratings

Whether you're an allergy or asthma sufferer, orpurifier.
someone who is concerned with providing your familyHEPA (High Efficiency Particulate Air) filters set the
with the best indoor air quality, finding a solution to thestandard for effective air cleaning. HEPA filters have
airborne contaminants in your home is a very importantbeen tested and certified to remove particles that
issue. The Environmental Protection Agency (EPA)average 0.3 micron in size. Particles of this size are
determined that most indoor air is three to five timeslikely to be inhaled and deposited into the lungs and
dirtier than outdoor air. This startling revelation led to atrigger allergic and asthmatic reactions.
boom in the production of air purifiers, but do theyTo qualify as a true HEPA filter, the filter must remove
really work?at least 99.97% of airborne contaminants, including
Most air purifiers remove airborne pollutants like moldmold spores, dust, pollen, smoke, and pet dander. There
spores, pollen, dust, bacteria, and pet dander. Butare many generic "HEPA-like" filters on the market
determining whether an air purifier is effective istoday; however, true HEPA filters are marked as such
measured by its ability to capture particles and theon their packaging and provide the most efficient
amount of air it can process in a given time.filtration.
Translation: If an air purifier can't catch particles of allMost air purifiers on the market are tested and
sizes and process enough air to make a difference, it'scertified by the Home Appliance Manufacturers
probably not worth the cost of shipping.(AHAM), using the Clean Air Delivery Rate, or CADR.
The effectiveness of an air purifier is generally basedThe CADR measures how many cubic feet per
on the effectiveness of its air filter. The Americanminute of air is cleared of certain size particles. Three
Society of Heating, Refrigeration and Air-conditioningparticle sizes are rated: smoke (small), dust (medium),
Engineers (ASHRAE) tests and certifies air filters, usingand pollen (large).
a rating system to ensure accuracy. The first rating,Rating air purifiers is simple: the higher the CADR rating,
Initial Staining Dirt Efficiency, measures how well thethe less time the unit needs to remove a given quantity
filter removes microscopic staining particles such asof particles from the specified size room. The room
tobacco tar, allergens, and grease. The second rating,size is indicated on the packaging of the air purifier and
the Average Arrestance Test, determines theall AHAM-certified models are marked with CADR
percentage of ordinary dust, hair, lint, and other largedata, as this information acts to distinguish each air
particulate matter removed. It's important to knowpurifier from its competitor. You can use the CADR
which rating is being used when comparing air purifiers.ratings to determine which air purifier works best in
The size of air contaminants like dust and pollenyour home.
particles is measured by the micron. The human eyeAs you can see, there are many standards and
cannot see particles that are smaller than 10 microns,ratings requirements used for all air purifiers. These
as one micron equals 1/25,400 of an inch. Particles likerequirements are used to ensure that every consumer
lint, dust, and pollen can all be seen by the human eye,receives the benefits they've been guaranteed by the
but smaller contaminants like bacteria and viruses willmanufacturer. Air purifiers can't guarantee the
escape the detection of our eyes and some filters.elimination of allergies or asthma. However, HEPA air
Finding a filter that will eliminate air impurities of all sizespurifiers can guarantee the elimination of harmful
is important to ensure the effectiveness of an airairborne contaminants.