Types of Air Purifiers
Portable Air Purifiers
If you suffer from allergies, asthma or any other condition that's made worst by airborne particles, a room air purifier may provide you with some -- or quite a bit -- of relief. People who smoke or have pets also like them for reducing odors, as well as removing smoke and pet dander. Some portable air purifiers use mechanical filters to clear the air, others use an electrical charge. Both technologies are discussed in more detail below.
Rather than purifying air one room at a time, another alternative is to consider a whole-house furnace filter. These aren't air purifiers; they simply replace your regular furnace filter. Most filters of this type do a pretty decent job of removing dust, pollen and smoke. Whole house filters need to be replaced every three months otherwise their airflow could be reduced, which makes them less effective. On the plus side, they don't use power and hence are less expensive on a yearly basis than any room air purifier.
Can air purifiers help you breathe easier?
Air purifiers do their work using
different technologies, and some use multiple technologies, to deal with
airborne pollutants. HEPA air purifiers use pleated high-efficiency particulate
arresting (HEPA) filters to mechanically trap particles, along with a fan to
pull air through the filter. Reviewers say this type of air purifier is by far the
most effective. These models don't produce any ozone, either. Because they use
fans, they can be noisy, but some actually like the sound an air purifier
makes, likening it to a white noise machine. Not every air purifier that relies
on mechanical filtration uses true HEPA filters, so be sure that you are
getting that technology if that's what you decide you want.
Some air purifiers use electronic
technology in place of or in addition to a mechanical filter. Electronic
ionizers work by reversing the charge of particles in the air. The charged
particles are then passed back out to the room where they are attracted to
objects such as clothing, walls, floors and furniture. In effect, particles are
removed from the air and deposited on your furnishings and clothing. You need
to dust and vacuum to actually remove allergens from the room and prevent them
from being reintroduced into the air. Some
air purifiers have an electrostatic precipitator that works by putting a charge
on particles and then collecting those using oppositely charged metal plates.
While both types of electronic air
purifiers are effective for collecting particles as small as .1 microns, they
can also produce a small amount of ozone, a lung irritant, though typically at
levels below the standard set as safe by Underwriters Laboratory and by
government agencies. Some electronic air cleaners put a small charge on a
mechanical filter to help it collect particles more effectively. With that type
of air cleaner, the charge is low enough that measurable amounts of ozone are
Ionic and electrostatic air purifiers
emit small amounts of ozone as a byproduct, but ozone generators sold as air
purifiers emit high levels intentionally to neutralize chemical irritants and
odors. Research has shown that, while this can be effective, it's also fairly
dangerous. The best advice we found is to avoid ozone generators altogether.
For more information, see our discussion of air purifiers and ozone elsewhere
in this report.
It's important to note that, with the
exception of ozone generators, none of the mechanical or electronic air
purifying techniques above are particularly effective against chemical gases or
strong odors. Some air purifiers add some type of chemical filtration -- typically
activated carbon -- to deal with those irritants. The most effective of those
sell for a premium price compared to the majority of air cleaners, but if you
suffer from chemical sensitivities, they might be worth every penny … or not.
For its part, ConsumerReports.org
notes in its review that "Some portable models with carbon pre-filters are
claimed to filter VOCs, but the Environmental Protection Agency warns that such
filters are specific to certain gaseous pollutants, not for others, and that no
air purifier is expected to remove all gaseous pollutants found in the typical
home." Furthermore, in a free article elsewhere on the site,
ConsumerReports.org's Mary H.J. Farrell says that "unless you have
allergies, you probably don't need [an air purifier]."
Finding The Best Air Purifiers
"Don't Spend Money on an Air Purifier You May Not Need"
To find the top performing
air purifiers, we consult professional reviews, such as those from
ConsumerReports.org and The Sweethome.com. We also consider whether or not an
air purifier has been submitted for testing and has had its ratings certified
by the Association of Home Appliance
Manufacturers (AHAM). Rounding things out, we analyze the hundreds and
sometimes thousands of user reviews some air purifiers have garnered at sites
like Amazon.com, AllergyBuyersClub.com and elsewhere. The feedback from
TheSweethome.com as well as by users proved to be particularly important in our
evaluations, because, as discussed below, it revealed that some well-regarded
air purifiers that looked like winners at first don't stand the test of time
all that well.
Armed with that
information, we consider factors such as performance (including long-term
performance), ease of use and noise. Finally, we analyze the full cost of the
unit, which includes both the initial cost and the ongoing costs of filter
replacement. The results of that research helps us to narrow down our recommendations
for the top air purifiers for any space or budget.
The best portable air purifiers
In reviewing air purifiers, we
discovered that the most satisfied customers are those who understand the
limitations of an air purifier and adjust their expectations accordingly. Portable
air cleaners can remove only airborne pollutants, they are not very effective
against dust mites and their droppings (those are too heavy to be airborne for
long), which are a significant allergen for many people. Most air cleaners also
don't remove most viruses, or gases like carbon monoxide and radon. That's
because even air purifiers with true HEPA filters are most effective on
particles larger than 0.3 microns, such as molds, pollen, dust, plant spores,
pet dander and the larger particles in cigarette smoke.
For this edition of our report, we are
going to elevate the (Est. $210) to Best Reviewed status.
This HEPA air purifier is currently the top pick at TheSweethome.com and gets
generally strong user reviews, including a 4.4 star rating at Amazon.com, based
on more than 460 reviews. It's
rated for rooms up to 326 square feet, making it suitable for all but the
largest master bedrooms. It's quiet, too, measuring only 51 dB (at a moderate
setting) in TheSweethome.com's test -- "far quieter than a typical
conversation," John Holecek and Tim Heffernan report. At its lowest
setting, this air purifier "is effectively silent on low at 42.7 decibels."
all wouldn't matter if the air purifier wasn't a capable performer, but it is
-- "reducing particle concentration to just 12 percent background level
after 20 minutes," Holecek and Heffernan say. A couple of other unit's in TheSweethome.com's
test performed a little better -- one beats it by a statistically insignificant
amount, but has higher operating costs, while the other performs significantly
better, but comes with some long-term reliability concerns (see below).
of reliability, the Coway looks to be excellent in that regard. User reviews of
units that failed prematurely or arrived non-functional are not unheard of --
and Coway's customer support is not well thought of by those who encountered
issues -- but are also relatively limited compared to owners who report
excellent performance. And that performance stays strong over the long haul.
TheSweethome.com is impressed: Though the HEPA filters have only a one-year
stated lifespan, "We ran our test model virtually nonstop for two years
without replacing them—twice what's recommended—and it still worked
as well as it did on day one."
plus for some is that the Coway is also quite a bit smaller than many air
purifiers, measuring 16.8 by 9.6 by 18.3 inches. The unit is available in
either glossy black or glossy white with a contrasting accent ring, which is a
welcome departure from typical air-purifier styling. "Simply put, it's
easy to live with," TheSweethome.com says. "You may well turn your
Coway Mighty on and never think about it again, and that's about the highest
compliment you can give an appliance."
icing on the cake is relatively low cost of ownership. The unit is less
expensive than may other air purifiers that cover similar-sized spaces, is
Energy Star qualified, and the filters are relatively reasonable in price -- the (Est. $60) includes a single
HEPA filter that should be replaced annually (strictly speaking, that is), plus
two carbon filters, which are swapped out every six months. "Another way
to look at this is: You could buy and maintain two Coway Mightys for five years
(perhaps one for the bedroom and another for the living room) for less than the
cost of some individual competitors," TheSweethome.com opines.
If you need something that can handle
a little larger room -- up to 465 square feet -- the (Est. $175) also gets good feedback. It's not been tested by
TheSweethome.com, but it is the second highest rated air purifier at
ConsumerReports.org, where it is a Recommended model. this HEPA air purifier is
effective at removing dust, pollen and smoke, especially at high speeds, though
it's also a very good performer at low. Noise levels are middling -- rated good
at both high and low speeds. The editors add that the unit is not especially
quiet, but is among the quietest air purifiers at high speed.
up-front costs are lower than the Coway, but while both models meet Energy Star
standards, the Honeywell's total energy consumption is higher (127 watts vs. 79
watts). On the plus side, the (Est. $40 for two filters) and (Est. $9) are relatively
reasonable in price. Still, ConsumerReports.org estimates an annual operating
cost of just over $200, making it one of the pricier air purifiers to own among
those it tested.
User feedback is largely excellent,
with ratings or 4.3 stars or better based on well over 1,000 reviews scattered
across the Internet. Most are pleased with overall performance. We did see a
number of comments that the unit was a bit loud, but other owners say that it's
fine in that regard.
Air purifiers for larger rooms
Both of the above air purifiers are
good choices for most rooms in your home, but if you need to purify the air in
a very large room, or have exceptionally dirty air, the (Est. $420) is a top choice. It gets a middling review at ConsumerReports.org, as the
testers there find that, while it is very effective when operating at high
speed, it doesn't do very well at low speeds. However, it's the step-up pick at
TheSweethome.com. "With a pair of filters, the Coway Airmega 300 is rated
to clear spaces as large as 1,250 square feet and will keep smaller spaces
exceptionally clean even on the lowest setting," Holecek and Heffernan say. For locations with
particularly bad air -- near a highway for instance -- this HEPA air purifier
can be set to filter the air in a space up to around 625 feet four times an
The Airmega is loaded with cutting
edge features. It can be set to monitor the air quality, sharing that
information with you via an LED ring. It can also be set to adjust the fan
speed and filtration rate based on those readings, and to shut itself off if
the air quality measures "good" for 10 minutes or so. A sleep mode
reduces fan speeds when the air quality is good for three minutes for quieter
operation while you are sleeping.
If all of that isn't "smart"
enough, there's a Wi-Fi enabled, version of the Airmega, the (Est. $585), that works with a proprietary app. The app
lets you remotely monitor the air quality in your home (or at least in the room
where the 300s is located) and can send you real time updates. It can also give
you the condition of the filter, let you remotely program the air purifier's
timer and more.
The 300s gets good user reviews, and
there's more feedback for it than for the non-Wi-Fi Airmega 300, but experts
are pretty lukewarm about the feature and the app earns few raves. "We
actually tested a 300S; six attempts to get the app to work failed,"
TheSweethome.com says, and it generally doesn't fare that well in the usual
tech publications, such as PCMag.com, that focus on the smart features
of devices such as this. For their part, TheSweethome.com questions the utility
of any "smart" air purifier, and considering the price premium that Wi-Fi
connectivity and access to the app adds to this already pricey model, this is
one case where we certainly agree. If the Airmega 300 is the right call for
your situation, save your money and get the base, non-connected, version as it
will clear the air every bit as effectively.
The Blueair Blue Pure 211 (Est.
is another option for a big room, but one that comes with a pretty big caveat
as at least one expert frets that there could be a significant drop of in
performance over time.
At TheSweethome.com, testers found
that the Blue Pure 211 is the most effective room air purifier overall, even
besting the Coway Mighty. However, the reviewers raise durability concerns
after another, previously top-rated air purifier made by the same company, the now-discontinued
but still-available-at-retail (Est. $660),
"nosedived" in performance when their sample unit was retested.
"It was among the worst-performing units in our 2016 test, using both the
original filters and brand-new filters," Holecek and Heffernan report. When contacting the
manufacturer, they were told that there were no user "remedies" for
the drop in performance, but that the maker would "fix" the unit --
for a $150 upfront charge. User reviews, while still not very extensive are
still positive overall. However we have also noted several owners who report
the same drop in performance, and a similar experience with the maker.
Because the Blueair Blue Pure 211 uses
the same charging technology as the 503, Holecek and Heffernan say they can't recommend either air purifier. However,
it's also worth noting that the Pure 211 does have a pre-filter, something that
the 503 lacks, and something that some users say is the real root of some of
the 503's reliability issues.
In contrast, ConsumerReports.org's
testers have no qualms regarding the Blue Pure 211. It's the top rated air
purifier there, and it also receives a Best Buy recommendation. The editors
find that it's excellent at removing dust, smoke and pollen at both high and
low speeds. Where other air purifiers have replaceable pre-filters, this model
has a washable fabric one, and that gets a thumbs up. The pre-filter is
available in five colors to fit a variety of decors. The main filter uses
mechanical and electrostatic filtering technologies to capture particles, and
the unit alerts you when it's time for that filter to be changed. The filter is
HEPA-type rather than true HEPA, but its air-cleaning performance has been
verified by the AHAM.
normally go to user reviews to break the tie between the top two expert reviews
that we found, but the Pure 211 is too new to have much of a track record with
owners at this time -- though what there is, is pretty good thus far. So, the
bottom line is that, at present, we can't elevate the Pure 211 to the ranks of
the Best Reviewed, but this is a model worth keeping an eye on down the line as
the durability issue sorts itself out. In the meantime, if you are adventurous
and like the attractive styling and great bang for the buck (assuming it lasts)
that the Pure 211 provides among larger room air purifiers, it might be worth a