Air Purifier Standards, Ratings

Whether you're an allergy or asthma sufferer, oreffectiveness of an air purifier.
someone who is concerned with providing your familyHEPA (High Efficiency Particulate Air) filters set the
with the best indoor air quality, finding a solution tostandard for effective air cleaning. HEPA filters have
the airborne contaminants in your home is a verybeen tested and certified to remove particles that
important issue. The Environmental Protectionaverage 0.3 micron in size. Particles of this size are
Agency (EPA) determined that most indoor air islikely to be inhaled and deposited into the lungs and
three to five times dirtier than outdoor air. Thistrigger allergic and asthmatic reactions.
startling revelation led to a boom in the production ofTo qualify as a true HEPA filter, the filter must
air purifiers, but do they really work?remove at least 99.97% of airborne contaminants,
Most air purifiers remove airborne pollutants like moldincluding mold spores, dust, pollen, smoke, and pet
spores, pollen, dust, bacteria, and pet dander. Butdander. There are many generic "HEPA-like" filters on
determining whether an air purifier is effective isthe market today; however, true HEPA filters are
measured by its ability to capture particles and themarked as such on their packaging and provide the
amount of air it can process in a given time.most efficient 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,certified by the Home Appliance Manufacturers
it's 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,and pollen (large).
using a rating system to ensure accuracy. The firstRating air purifiers is simple: the higher the CADR
rating, Initial Staining Dirt Efficiency, measures howrating, the less time the unit needs to remove a
well the filter removes microscopic staining particlesgiven quantity of particles from the specified size
such as tobacco tar, allergens, and grease. Theroom. The room size is indicated on the packaging of
second rating, the Average Arrestance Test,the air purifier and all AHAM-certified models are
determines the percentage of ordinary dust, hair, lint,marked with CADR data, as this information acts to
and other large particulate matter removed. It'sdistinguish each air purifier from its competitor. You
important to know which rating is being used whencan use the CADR ratings to determine which air
comparing air purifiers.purifier works best in your home.
The size of air contaminants like dust and pollenAs you can see, there are many standards and
particles is measured by the micron. The human eyeratings requirements used for all air purifiers. These
cannot see particles that are smaller than 10 microns,requirements are used to ensure that every
as one micron equals 1/25,400 of an inch. Particles likeconsumer receives the benefits they've been
lint, dust, and pollen can all be seen by the humanguaranteed by the manufacturer. Air purifiers can't
eye, but smaller contaminants like bacteria andguarantee the elimination of allergies or asthma.
viruses will escape the detection of our eyes andHowever, HEPA air purifiers can guarantee the
some filters. Finding a filter that will eliminate airelimination of harmful airborne contaminants.
impurities of all sizes is important to ensure the