Frank Gaydos on wed 14 mar 07
My workplace, the Community College of Philadelphia, is on strike this week=
, so I have time on my hands, not always a good thing. :>)=0AI noticed tha=
t some clayart members were considering the purchase of certain filters.=0A=
I used to have an electronic, electrostatic filter but noticed that after i=
t charged the dust particle, the dust would attach itself to the nearest wa=
ll or furniture making it almost impossible to clean. Some may suggest that=
is better than being in your lungs. But, they have other issues, see below=
.=0A =0AFrank Gaydos=0AOzone issues=0AAir purifiers like The Sharper Image =
Ionic Breeze Quadra (*est. $350) , Oreck XL (*est. $370) and Friedrich C-90=
B (*est. $500) are electrostatic air cleaners (though the Friedrich also in=
cludes other air-filtering technologies like filters and a fan). This means=
that they use an electrical charge. A byproduct of this technology is ozon=
e gas. In sufficient quantities, ozone can be toxic; but even in smaller am=
ounts it can irritate those with asthma or other respiratory problems.=0AAl=
though some reviews say that the ozone produced by electrostatic air cleane=
rs is safe for those in normal good health, both the U.S. Environmental Pro=
tection Agency (EPA) and American Lung Association (ALA) advise against usi=
ng these devices, since there are many ozone-free HEPA models on the market=
. While there are no government guidelines for ozone levels in the home, th=
e Food and Drug Administration (FDA) does have an ozone regulation for medi=
cal devices (the FDA does not recognize home air cleaners as medical device=
s), and air-purifier manufacturers may voluntarily submit their air cleaner=
s for ozone-emission testing. The FDA mandates a limit of 50 parts-per-bill=
ion (ppb) when measured at 2-inches away from the unit. =0AConsumer Reports=
replicates this test for ionizing air purifiers, including the Ionic Breez=
e and Friedrich C-90B. While past versions of the Ionic Breeze exceeded the=
FDA ozone-emission guidelines, the latest versions do not, coming just wit=
hin the guideline. The Friedrich C-90B falls well below the 50ppb limit. =
=0A=0A =0ASave & share this report (What's this?)=0A Yahoo! =0ADigg! src=3D=
"http://www.consumersearch.com/images/marklet/digg.gif"> Digg =0AGoogle src=
=3D"http://www.consumersearch.com/images/marklet/google.gif"> Google =0ARed=
dit src=3D"http://www.consumersearch.com/images/marklet/reddit.gif"> Reddit=
=0A del.icio.us =0AThe jury is still out on whether small amounts of ozone=
are harmful in healthy individuals. There have been a lot of studies on th=
e health effects of outdoor ozone levels, but few long-term tests have meas=
ured the effects of ozone produced by indoor devices like air cleaners. One=
2006 study published in the Journal of the Air & Waste Management Associat=
ion tested 13 air purifiers, including several personal air cleaners design=
ed to be in close proximity to a person. Research analysts concluded that e=
ven these are capable of producing steady-state levels of indoor ozone that=
exceed health-protective standards. Indeed, some people say they can smell=
ozone, and some report headaches. Some reviewers, including Consumer Repor=
ts, say you should avoid air cleaners that produce ozone over the FDA guide=
lines, while other organizations say you should avoid home air purifiers th=
at produce any amount of ozone at all. While all reviews say the Friedrich =
C-90B does an excellent job
removing allergens from the air, it does produce small amounts of ozone as=
a byproduct.=0ADo you really need an air purifier?=0AAir purifier sales ha=
ve soared amid ongoing concerns about environmental terrorism and diseases =
such as SARS and bird flu. But many experts, including those at Consumer Re=
ports, say that most people really don't need an air purifier at all. Altho=
ugh home air cleaners can be effective against larger airborne particles su=
ch as pet dander, dust and smoke, all of those allergens can be better cont=
rolled at the source by removing elements in the home that produce dust and=
by not smoking indoors, as well as by regular vacuuming and dusting.=0ASin=
ce portable air cleaners can remove only airborne pollutants, they're not v=
ery effective against dust mites and their droppings (which are too heavy t=
o be airborne for long), a significant allergen for many people. They also =
don't remove most viruses or gases like carbon monoxide and radon. That's b=
ecause air filters are most effective on particles larger than three micron=
s, such as molds, pollen, dust, plant spores, pet dander and the larger par=
ticles in cigarette smoke. Air Purifiers America measures down to .3 micron=
s, which includes most pet allergens, smog and germs. =0AMost reviews agree=
that those with severe allergies, asthma and bronchitis -- who need to con=
trol indoor air quality as much as possible -- may benefit most from air pu=
rifiers, but only when used in conjunction with other allergen source-contr=
ol strategies, including ventilation and daily HEPA vacuuming. These review=
s say there's little evidence that air purifiers are effective alone. The A=
llergy and Asthma Network/Mothers of Asthmatics admonishes, "Air filters do=
n't replace the need for eliminating or reducing indoor allergens. Beware o=
f any manufacturer making health claims."=0AThe U.S. Environmental Protecti=
on Agency (EPA) has an excellent document titled "Residential Air Cleaning =
Devices: A Summary of Available Information" (see our Best Research section=
below for the link to that article). The EPA doesn't take a position eithe=
r for or against home air cleaners, but states, "Some air purifiers, under =
the right conditions, can effectively remove certain respirable-size partic=
les" (for example, larger tobacco smoke particles). Both the EPA and Americ=
an Lung Association recommend that air purifiers be used as a last resort a=
fter allergen source control and ventilation. According to Consumer Reports=
, "In short, only those with respiratory problems are likely to benefit fro=
m using an air cleaner."=0ABefore you run out and buy a $500 air purifier, =
you might make a $15 investment and try a simple whole-house furnace filter=
. If you have forced-air heating or cooling, these filters simply replace y=
our regular furnace filter. Filters such as the 3M Filtrete Ultra (*est. $1=
5) are effective at trapping particles like dust and pollen, but aren't ver=
y effective with smoke. Filters need to be replaced every three months,and =
3M even provides e-mail reminders from its website. =0AAlthough such filter=
s can reduce airflow in your system, we think they are worth a try if your =
main problems are airborne dust, pet hair and dander. A $15 furnace filter,=
according to Consumer Reports, can be just as effective as room-sized mode=
ls in removing those allergens at a much lower cost.=0ATypes of air purifie=
rs=0AThere are three main types of console-type air purifiers on the market=
right now. Many air cleaners use combinations of techniques.=0AHEPA air pu=
rifiers. These air cleaners use pleated High Efficiency Particle Arresting =
(HEPA) filters to trap allergens, along with a fan to pull air through the =
filter. By a wide margin, reviews say this type of air purifier is the most=
effective. These models don't produce any ozone at all. Because they use f=
ans, they can be noisy in confined spaces, but some are quieter than others=
.=0AElectronic ionizers. This type of air cleaner uses an electronic proces=
s to reverse the charge of particles in the air. The charged particles are =
then attracted to collection plates in the air purifier, as well as to obje=
cts in the room -- such as clothing, walls, floors and furniture. In effect=
, particles are removed from the air and deposited on your furnishings and =
clothing. To actually remove them from the room, you need to dust and vacuu=
m to prevent allergens from being reintroduced into the air. The Sharper Im=
age Ionic Breeze is this type of unit. Since it does not have a fan, howeve=
r, experts say not enough air actually comes in contact with the charging p=
lates. The Friedrich C-90B is a better application, since it also uses a fa=
n and a HEPA filter. Electronic and electrostatic models like the Ionic Bre=
eze and Friedrich C-90B produce a small amount of ozone, as discussed above=
. =0AOzone generators. Some air purifiers do nothing but produce large amou=
nts of ozone. These units do not remove allergens from the air. Ozone in la=
rge amounts can neutralize strong odors (such as the smoke odor from fire d=
amage), but according to the EPA, this is dangerous for human health. These=
air purifiers get around the FDA limits for ozone production by not claimi=
ng to be medical devices. One manufacturer -- Alpine Technologies -- says t=
hat its ozone generators, such as the Natural Air (*est. $400) should be us=
ed on a high setting only "while people and animals are gone." Ozone alone =
has no effect on particulate allergens at all.=0AHEPA air purifiers=0ABoth =
Consumer Reports and Air Purifiers America test a wide range of HEPA air cl=
eaners, which start at about $250 for mid-sized units. While it's easy to s=
pend upwards of $700 on a home air purifier, most users probably don't need=
the kind of high-level, multi-filtered performance these high-end models p=
rovide. The top-rated models at Allergy Buyers Club are $600 to $1,500 IQAi=
r HealthPro air cleaners, most of which can filter viruses, bacteria, chemi=
cal gases, volatile organic compounds, sulfuric gas and ammonias. =0AAir Pu=
rifiers America and Allergy Buyers Club rate the IQAir HealthPro (*est. $70=
0) as the best purifier on the market if you have severe allergies. Reviewb=
oard Magazine awarded the IQAir its Editor's Choice Award For Best Air Filt=
ration System two years in a row (2004 and 2005), and this brand was chosen=
by the Hong Kong Hospital Authority for use during the SARS outbreak. Test=
Magazine, the German equivalent of Consumer Reports, also gives the IQAir =
HealthPro top scores in a ten-model roundup. The IQAir HealthPro air purifi=
er can clean up to a 900-square-foot room and uses a HyperHEPA filter, whic=
h has a filter-change alert and is easy to change every two to four years. =
=0ATop scores from Air Purifiers America and Test Magazine, along with a wi=
de range of other endorsements, convinced us to include the HealthPro air c=
leaner in ConsumerSearch Fast Answers. If you have a severe medical conditi=
on and need "critical decontamination," then you should take a closer look =
at the IQAir HealthPro. But for most allergy and asthma sufferers, a high-q=
uality, mid-priced HEPA air purifier fits the bill. HEPA filters can remove=
99.97% of particles larger than .3 microns, enough to help improve indoor =
air quality and reduce exposure to irritants and allergens.=0AThe Whirlpool=
Whispure 45030 (*est. $270) performs very well in one large comparison tes=
t. Whirlpool also makes air purifiers for Kenmore. For example, the Kenmore=
83202 (*est. $300) is nearly identical to the Whirlpool model. Both units =
have a pre-filter for odors, a filter-change indicator and push button cont=
rols. This basic style of purifier doesn't have a lot of extra features, bu=
t reviewers say it does the job efficiently. The filter replacement costs c=
an add up though. The pre-filter should be replaced every three months (*es=
t. $30) and the HEPA filter should be replaced every year (*est. $100), for=
a total annual expense in the $220 range. The Kenmore and Whirlpool air pu=
rifiers are rated for up to a 500-square-foot area, about half the area cov=
ered by the IQAir air cleaner above. =0AThe Whirlpool Whispure 45030 is har=
d to find in stores, even though it hasn't been officially discontinued. Fo=
r that reason, we've included the similar Whirlpool-made Kenmore 83202 in F=
ast Answers. One consumer posting to Epinions describes a problem with the =
Kenmore 83202 overheating and subsequent trouble with Sears' customer servi=
ce. We didn't find any other complaints about this, but keep in mind that t=
his Kenmore air purifier only has a one-year limited warranty.=0AAustin Air=
air purifiers are tested at both Air Purifiers America and Consumer Report=
s, including the HealthMate HM400 (*est. $400) . As with the IQAir air clea=
ner, these organizations come up with different test results for the Health=
Mate 400, but as explained to us when we contacted Air Purifiers America, t=
his is likely due to different measurement methods. Reviews say Austin Air =
air purifiers aren't adept at removing smoke particles, but they do a reaso=
nable job with dust and pollen. Syndicated columnist, environmental enginee=
r and allergy sufferer James Dulley uses an Austin Air in his bedroom. In o=
ne head-to-head test, however, the IQAir air purifier gets better scores fo=
r allergen removal. The Austin Air Jr (*est. $300) , a smaller, less expens=
ive model than the HealthMate HM400, is also available. =0AAlthough it isn'=
t tested at Consumer Reports, the Alen 350 (*est. $400) outperforms the Aus=
tin Air HealthMate at Air Purifiers America, and when run on high speed, te=
sters say it is notably quieter than the IQAir HealthPro air purifier. In a=
ddition, the Alen 350 has one filter cartridge, which contains the HEPA fil=
ter, carbon filter and pre-filter all in one, so replacement filter costs a=
re less than with the Kenmore or IQAir air purifiers. Filters should be rep=
laced every six to nine months (*est. $40 each). The Alen 350 air purifier =
can clean up to 800 feet.=0AAccording to reviews, the Blueair 601 (*est. $6=
00) is one of the quietest models (on low speed) on the market. The Blueair=
is stuck in the same spot as the IQAir home air purifier -- highly rated a=
t Air Purifiers America, but not as highly rated in other types of tests. T=
he Blueair does have great airflow. According to the Association of Home Ap=
pliance Manufacturers' (AHAM) 2005 Directory of Certified Room Air Cleaners=
, it has the third-highest CADR (clean air delivery rate) score among 33 br=
ands for dust, pollen and smoke removal (more on CADR in The Buzz below). O=
nly Dri-Eaz and the Korean Nano Biothys are slightly higher. The Blueair 60=
1 can handle up to a 679-square-foot room and has a ten-year warranty, as l=
ong as filters are changed every six months (the filters cost about $25 eac=
h). By combining a HEPA-like filter and an electrostatic filter, some revie=
ws say the Blueair captures a higher percentage of allergens without releas=
ing ozone into the air, like other
electrostatic models. However, in tests, the cheaper Alen 350 air purifier=
performs as well.=0AIn general, higher priced air purifiers have better fi=
lters and larger fans, which enables more air to be processed through the a=
ir cleaner. According to reviews, the trouble with smaller, less expensive =
air purifiers is that they don=92t pull a sufficient amount of air through =
the unit. Just about the least expensive air purifier to receive good revie=
ws is the Honeywell Enviracaire 50250 (*est. $150) . This circular air puri=
fier has a pre-filter for odors (replacement filters *est. $12, every three=
months) and a HEPA filter (replacement filter *est. $20, replace once a ye=
ar) to trap allergens. It is designed for use in rooms up to 375 square fee=
t. In tests, the Honeywell is a little less effective than the Kenmore 8320=
2 air purifier, and it's noisier.=0AAn even less expensive option is the Ha=
milton Beach TrueAir 04481 HEPA air purifier (*est. $90) . An older version=
, the TrueAir 04161, received a mention from two reviewers for Best Value, =
although we haven't seen the currently available Hamilton Beach 04481 revie=
wed yet. The three-speed 04481 is only rated for a 230-square-foot room, ev=
en smaller than the Honeywell Enviracaire above. As of the time of this upd=
ate, Hamilton Beach hasn't submitted any of their models for AHAM CADR cert=
ification.=0ACombination air purifiers=0AThe Friedrich C-90B (*est. $500) g=
ets good performance scores across the board from experts, but because it u=
ses an electronic precipitator in conjunction with a HEPA filter and fan, i=
t produces a small amount of ozone. The C-90B is an upgrade from the C-90A =
discussed in our previous reports, and it has an improved clean air deliver=
y rate of 18% over the older model. The Friedrich uses a combination of tec=
hnologies, including several pre-filters and a fan to pull air through the =
machine in order trap allergens. It also uses an electrostatic ionizer to c=
harge remaining particles, which attach to collection plates within the uni=
t -- and possibly to your furniture, walls, and/or floors.=0AThe Friedrich =
C-90B is the top performer in one comparison test of over two dozen air pur=
ifiers. Most of the other reviews we found were still for the older C-90A. =
Air Purifiers America docks this model a few points because they say the Fr=
iedrich is less effective on high speed, plus several owners have returned =
these machines because of an annoying odor emitted by the unit. Some consum=
ers report the odor as a musty smell, which is most likely the small amount=
of ozone produced by this model, since it uses electrostatic plates in add=
ition to filters to trap particles. In people who are sensitive to it, incl=
uding those with severe allergies, the ozone odor may be off-putting and/or=
may cause headaches (as it did to two editors who evaluated it for separat=
e publications) or respiratory problems.=0ATwo reviewers also point out tha=
t while the older Friedrich C-90A is generally one of the quietest models o=
n the market, it can make some crackling sounds if the plates are not kept =
clean. According to Allergy Buyer's Club.com (which tests air purifiers for=
noise and ease-of-use), "Even when it doesn't need cleaning you will hear =
little zapping sounds periodically." =0AReviewers say the Friedrich C-90B i=
s one of the more effective air purifiers out there, but you may be sensiti=
ve to the small amount of ozone it produces, or the "little zapping sounds"=
might really get under your skin. However, this model does a very good job=
at removing allergens, and it is very quiet on low speed. Because this uni=
t =96 like most air purifiers =96 uses a fan, high speed can be noisier. Bu=
t the fan is needed to pull air through the cleaner. Part of the problem wi=
th the Ionic Breeze Quadra is that it has no fan. While this makes it very =
quiet, reviews say that little air is pulled through the machine. Owners co=
ntributing to surveys at Air Purifiers America give the Friedrich high scor=
es for low noise level. =0AThe Bionaire BAP825-U (*est. $80) is an example =
of a lower-priced combination model. This Bionaire air cleaner is only mean=
t for bedrooms, but it's one of the least expensive models available. Howev=
er, reviews say that small models like the Bionaire don=92t clean very well=
(since their filters are smaller) and that they are noisier (since their b=
lowers work harder to pull air through a smaller filter). This Bionaire use=
s a HEPA filter (*est. $35 annually), with an odor-reducing carbon pre-filt=
er (*est. $14 annually). The Bionaire BAP825-U contains an ionizer, but thi=
s can be turned on and off with a switch on the top of the unit. However, r=
eviews say the inexpensive Bionaire just doesn't work that well. You might =
eliminate more allergens by vacuuming or dusting more frequently.=0AThe Fre=
sh Air Machine by Science Air (*est. $200) has similar features to the Bion=
aire, but for a higher cost. The Fresh Air Machine also uses a combination =
HEPA filter and ionizer, and like the Bionaire, the ionizer can be turned o=
ff. Interestingly, the higher priced Fresh Air Machine has a shorter warran=
ty -- only one year compared to the Bionaire's two-year warranty. As of the=
time of this update, neither of these combination models are mentioned by =
reviewers or included in current air purifier tests.=0AAnother air purifier=
creating a buzz is the Fresh Air by EcoQuest (*est. $800). Ecoquest was st=
arted in 2000 by a former executive of its predecessor, Alpine Industries. =
In the late 1990s, the Minnesota Supreme Court ruled against Alpine Industr=
ies for making misleading health claims, and in 2000, a federal judge again=
ordered the company to stop making claims that its machines relieve medica=
l conditions or that they effectively remove indoor air pollutants. Subsequ=
ently, both Alpine Industries and EcoQuest were named in a complaint filed =
by the Federal Trade Commission and U.S. Justice Department. Alpine Industr=
ies was fined $1.49 million on the health claim charges, and it also came t=
o light that the company owed a large amount of back taxes to both Minnesot=
a and Tennessee.=0AEcoQuest markets its air purifiers primarily through a l=
arge network of affiliate salespeople, and these air purifiers are often so=
ld by enterprising entrepreneurs, sometimes door-to-door. EcoQuest's Fresh =
Air purifier has a five-speed fan, a carbon filter and uses an ultraviolet-=
light ionizer. The manufacturer claims that the ionizer reduces airborne co=
ntaminants, while the ultraviolet light kills microorganisms. Like the Ioni=
c Breeze, the EcoQuest produces ozone as a byproduct of ionization. One con=
sumer posting to Epinions notes that her EcoQuest "died years too early" an=
d says that this model doesn=92t work in humid climates. This, along with t=
he company's history, makes us pause. While the Fresh Air hasn=92t been inc=
luded in independent comparative testing yet, we think that for the price, =
you might better consider other models, such as those mentioned above, that=
have been proven to clean air without the ozone risks. While there is soli=
d research evidence showing the
germicidal properties of ultraviolet light, as claimed by the EcoQuest, yo=
u'll want to be careful of models that use ultraviolet light simply to prod=
uce ozone in order to eliminate odors, like the AirSource and Natural Air d=
iscussed below. =0AElectrostatic ionizers=0AThe Sharper Image Ionic Breeze =
models are electronic ionizers. They do not have fans or HEPA filters. Rath=
er, they charge particles close to the unit so that those particles fall to=
the floor or stick to furnishings. But experts say that the Ionic Breeze d=
oes not remove enough particles from the air -- in part because it lacks a =
fan to pull air through its charging plates. In tests at Air Purifiers Amer=
ica, particle removal within the room was only 5%. Editors report that they=
"even tested this unit beyond our standard 20 minute duration and extended=
it for an entire day. This unit still didn't remove any significant partic=
les from the room."=0AA number of other models are trying to steal some mar=
ket share from The Sharper Image, which sells more units than any other man=
ufacturer by far. The AirSource 3000 (*est. $700), distributed by Shaklee C=
orporation, uses ultraviolet light to produce low levels of ozone to reduce=
odors, as well as an electron generator to "reduce the static charge insid=
e the entire home=94 so =93particles drop from the air and out of your brea=
thing space." Like the Ionic Breeze, the AirSource doesn=92t have a fan, so=
it=92s quiet but also can=92t pull large amounts of air through it. Furthe=
rmore, all those particles dropping out of the air are likely accumulating =
on furnishings and walls. =0ASimilarly, the Biotech EdenPURE (*est. $300) u=
sed ultraviolet light and "activated oxygen" in its previous model. The lat=
est EdenPURE model claims to use "4 electronic mechanisms of eliminating po=
llution that mimic the way it is done by nature=92s thunderstorm." In short=
, this means ionization. However, the EdenPURE makes some pretty lofty clai=
ms about eliminating all odors and all indoor pollution without a HEPA filt=
er, and the manufacturer states it only uses a small mesh pre-filter that c=
an be cleaned by running water over it. This leads us to think that all tho=
se contaminants are accumulating on your furniture and walls, as with other=
ionizing models.=0AOzone generators=0AAir purifiers that only produce ozon=
e do not remove allergens from the air. Ozone in large amounts can neutrali=
ze strong odors (such as the smoke odor from fire damage), but according to=
the EPA, it is dangerous for human health. These units get around the FDA =
limits for ozone production by not claiming to be medical devices. Many of =
these units, however, walk a fine line by suggesting that ozone has some ki=
nd of health benefit.=0AAlso watch out for manufacturers who disguise ozone=
by other titles, such as "pure air," "energized oxygen," "saturated oxygen=
," or "trivalent oxygen." See the EPA's document: "Ozone Generators that ar=
e Sold as Air Cleaners: An Assessment of Effectiveness and Health Consequen=
ces." (Find a link below in our Best Research section.) If you already own =
an ionizer and are curious about whether it's producing ozone, the not-for-=
profit International Association of Air Cleaner Manufacturers (IAACM) offer=
s free ozone test kits to consumers so they can test their own air purifier=
s for ozone production. To get a free test kit, send a self-addressed stamp=
ed envelope to IAACM, P.O. Box 9048, Whittier, CA 90608-0948.=0AThe Natural=
Air purifier (*est. $350) produces negative ions to attract air pollutants=
, along with ozone production to reduce odors. In fact, the manufacturer's =
website openly states that the Natural Air models are ozone generators and =
should only be used on high speed "while people and animals are gone." This=
is different from the Ionic Breeze, for example, which is an ionizer that =
produces ozone as a byproduct, but not as the direct means for cleaning air=
. =0AImportant Features: Air purifiers=0AThe science of air cleaning can be=
confusing, and the way manufacturers present scientific information is oft=
en misleading. The truth is, unless you're an excellent mathematician, it's=
difficult to determine which air cleaner is right for your specific needs,=
because you must weigh initial costs, frequency and cost of maintenance, p=
ower requirements, level and sources of pollution, room size and unit effic=
iency. On top of all this, there's no mandate from any independent scientif=
ic source that says what works best.=0AWith all that in mind, reviews say t=
o look for the following in an air cleaner:=0AA Clean Air Delivery Rate (CA=
DR) that matches the size of the room to be cleaned. CADR is a standard dev=
eloped by the independent Association of Home Appliance Manufacturers (AHAM=
) to measure the removal of dust, smoke and pollen from the air. CADR measu=
res the amount of clean air (in cubic feet) that an air cleaner delivers to=
a room per minute. A CADR of 50 is appropriate for a room of 80 square fee=
t; a CADR of 80 for 120 square feet; a CADR of 100 for 144 square feet; and=
a CADR of 200 for 320 square feet. However, not all manufacturers have sub=
mitted their models for CADR testing. =0AA High Efficiency Particulate Arre=
sting (HEPA) filter is the best way to filter air. Experts generally agree =
that true HEPA filters, which trap 99.97% of particles, are the most effici=
ent pollutant removers on the market. Some filters advertise themselves as =
HEPA or "HEPA-type" filters, but unless the word "true" appears in front, t=
hey may be lower-grade filters that don't trap as many pollutants. =0AElect=
rostatic ionizers charge particles so that they fall to the floor or cling =
to furnishings. Electrostatic ionizers charge particles in order to acceler=
ate their fall to the floor (and hence remove them from the air). You then =
need to dust or vacuum to actually remove the allergens from your living sp=
ace. Consumers should be aware that most electrostatic devices produce a sm=
all amount of toxic ozone as a byproduct. Some models use ionizers in conju=
nction with other filters, using collection plates for the charged particle=
s. Some of these combination machines, like the Blueair (which produces no =
ozone) and the Friedrich C-90B have been found effective, but you have to w=
eigh that benefit against whether you're comfortable breathing small amount=
s of byproduct ozone. =0AModels with fans work better in tests. Without a f=
an, air isn=92t pulled through the unit to either charge particles and/or f=
ilter them through a collection media, like a HEPA filter. =0AA filter moni=
tor alerts you when filters need to be changed. Proper maintenance is cruci=
al for air filter effectiveness. Once filters become clogged with particles=
, they can actually turn into air polluters, churning contaminants back int=
o circulation. Some monitors have visual or audio cues that prompt you to c=
hange the filter. This feature is not essential; since most HEPA filters ne=
ed to be changed about once a year, it's easy enough to mark the date on yo=
ur calendar. =0AA noise level you can accept. Look for models with differen=
t fan speeds, so you can control the noise level. However, according to Mer=
cia Tapping, president of Allergy Buyers Club, "Vendors routinely overstate=
the effective cleaning area of a machine because the area is calibrated at=
the machine's high fan speed. Now, try to sleep with that fan on high -- i=
t sounds like a train going through your bedroom." Some reviewers, includin=
g Consumer Reports, suggest buying a larger unit than you need for a bedroo=
m, then running it on low speed to cut down on noise.
Josh Berkus on thu 15 mar 07
Frank,
> I used to have an electronic, electrostatic filter but noticed that after
> it charged the dust particle, the dust would attach itself to the nearest
> wall or furniture making it almost impossible to clean. Some may suggest
> that is better than being in your lungs. But, they have other issues, see
> below.
The bigger issue with ones like the "Ionic Breeze" is that they do absolutely
nothing. Heck, Sharper Image sued Consumer Reports to try to cover up CR's
report on the Ionic Breeze.
--
The Fuzzy Chef
San Francisco
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