The Air Purifier Clean Air Delivery Rating: CADR

The Association of Home Appliance Manufacturersso useful to marketers of mass produced air
(AHAM), which tests air purifiers, certifies, andpurifiers.
publishes Clean Air Delivery Rates (CADR), is aFirst, and worst, CADR does not measure
home appliance manufacturers industry lobbyingremoval of the health hazards we buy air purifiers
group.to collect! Experienced users will have noticed the
In the 1980's AHAM established a testing systemlarge particle size specified: .9 to 11 microns. The
and certification program for portable room airlarger particle size focus is far above the .3
purifiers: Clean Air Delivery Rate.micron HEPA range, it favors cheaper units.
The delivery rate was designed to "help" buyersSince 90% of all particles are smaller than .3
evaluate air cleaners. Objective standards were,microns, and these tiny fragments are the most
and still are, needed. It is difficult to critique ahazardous to health, what is important is the air
flawed system which stands between consumerspurifier's ability to remove sub-micron particles in
and anarchy.the .5 micron and smaller range. CADR is designed
Air purifier advertising often claims that the AHAMto divert attention away from this critical area.
delivery rate is the key information consumersSecondly, CADR is completely irrelevant to
should use to evaluate air purifier performance.chemical contamination of all kinds. Volatile Organic
"Just look for the AHAM seal."Chemicals (VOC's) are molecular sized.
AHAM uses an independent laboratory to verifyNext to them .9 microns is the Rocky Mountains.
clean air exhaust volumes submitted byAir purifiers with real carbon chemical filtration and
manufacturers for given air purifier models.tightly sealed and gasketed filters are at a big
Air cleaners are rated for ability to remove dust,disadvantage in the CADR game. With real carbon
pollen and smoke.filters and ultraviolet light air purifiers, faster is not
CADR tests last only 20 minutes.necessarily better.
A closed chamber is filled with dirty air to clean;Third, the short tests obscure long term
particles ranging in size from .09 microns to 11performance shortcomings of electrostatic
microns, represent tobacco smoke, mulberryprecipitators and inferior HEPA models, both of
pollen or Arizona road dust.which have efficiency declines with age.
Clean air delivery rate is the volume of air that aAHAM certification is voluntary, and only 27
specific air purifier cleanses of a specific particulatecompanies have joined up. Builders have to pay a
pollutant in cubic feet per minute.fee as high as $10,000 to have their product
Strong air purifiers have CADRS in the 400 area,certified. AHAM also extracts a commission on
machines rated below 100 are very weak.every sale of a box bearing the CADR seal. Who
The AHAM CADR directory is published twice apays for this? Buyers do.
year.Many quality brands and smaller companies have
So what's wrong with the AHAM delivery rate?not submitted their products to AHAM.
It's what CADRs avoid saying that makes them