There are some very good air purifiers on the market by such
companies as Oreck®, Honeywell®, Austin®, Friedrich®, Hunter®, Kenmore®,
IQAir®, Blueair®, Electrolux®, Panasonic®, Airfree®, Holmes®, Prozone®,
FreshAir®, EcoQuest®, Biozone®, Bionaire®, Whirlpool®, Sharper Image®,
Sila®, Hamilton Beach®, GE®, Lumipure®, Amcor®, Lifewise®, Bell &
Howell®, Delonghi®, Aranizer® and Surround Air®, but you must understand
the technical differences among these purifiers before you can find one
that's right for you.
HEPA Filter air purifiers
HEPA filters employ a cloth type filter that can trap 99.9% of
particles 0.3 microns or larger in size, and a fan to move air through
the machine. HEPA filters can be very effective in clearing out almost
any harmful particles from the air in a room. These devices usually have
a replaceable filter that can last several years depending on how filthy
the air is in your home. Although some don’t like the noise level of a
HEPA machine, it can usually remove more pollutants than a ionic
machine.
Advantages: allergens are captured; not being released into the air
once trapped. Disadvantages: Does not eliminate chemical fumes, gases,
cigarette smoke, or odors
Ozone air purifiers
Ozone is a highly reactive oxidant that destroys certain bacteria,
chemicals, bacteria and chemicals. Although ozone is very effective
against strong odors, there is a caution you should consider.
When ozone reacts with substances in the air, the substances are
broken down into other materials that are also pollutants. This is where
the controversy lies with ozone machines. You can run ozone machines on
low (if they are adjustable), which manufacturers often advise. However,
if you are clearing a room from smoke or odors you can run it on high
while keeping people out of the environment altogether. Later, turn the
machine off and open windows to clear out the ozone.
Advantages: Extremely effective against odors. Disadvantages: Not
effective on allergens and most chemicals.
Carbon air purifiers
Activated carbon air filters consist of a system of pores that are
tiny in size. These pores are highly adsorbent, chemically reacting to
particles that pass through them and the particles and odors actually
bond with the carbon.
This is the most absorbent filter on the market today, so it is
extremely effective in capturing certain types of particles (see the
chart below for more information). Note that most carbon activated
devices also incorporate HEPA technology, thereby combining the
advantages of both types of technology.
Advantages: Highly effective with chemicals, gases, smoke, and odors.
Disadvantages: Not effective with allergens and micro-organisms.
Ionic air purifiers
Ionic air purifiers do not have a cloth filter like the HEPA
machines. They work by "ionizing" the air, causing particulates to gain
a positive or negative charge. Why charge the particles?
The charge is necessary for two reasons. The air ionizer contains
collection plates that have an opposite charge from the particles in the
air, so the particles are drawn to the collection plates (these are
referred to as “capture” ionic purifiers). Also, the particulates can be
attracted to other particles that have an opposite charge. When this
happens the two particles with opposite charges wind up sticking
together and falling out of the air (these machines simply release ions
into the air without capturing them on plates). By the way, many people
like ionizers because they are very quiet compared to most HEPA
machines.
Advantages: can remove extremely fine particles anywhere in a room;
even several feet away from the machine. Disadvantages: Not effective on
odors; doesn't kill germs but removes them from household air.
Ultraviolet light air purifiers
Ultraviolet (UV) lamps are known to sterilize micro-organisms that
pass through it, including germs, viruses, bacteria, and mold; so
microorganisms, after treated with this light, can no longer reproduce
and grow. At least we know this to be true when UV light is used in
sufficient dosage and a sufficiently long period of time to do its job.
When used in an air purifier, does the UV light have enough time to
perform and sterilize correctly while air is moving through it, possibly
at a brisk rate of speed? There is an innovative approach that uses UV
lamp combined with a HEPA filter, so particles trapped in the filter can
be treated with UV light for an effective amount of time.
Advantages: Helps destroy microorganisms that cause disease.
Disadvantages: Not effective on allergens, smoke, odors, or chemicals.
Purifying hydroxyl radicals
Hydroxyl radicals are powerful cleansing agents that occur naturally
in the Earth’s atmosphere. They are created when oxygen atoms pull a
hydrogen atom from water vapor, which then form the radical. Hydroxyl
radicals are 1,000,000 times faster at destroying pollutants in the air
than ozone. They are the most powerful method of neutralizing mold,
bacteria, and viruses.
New proprietary technology has combined hydroxyl radical technology
with ultra violet light and negative ions resulting in an air purifying
system that neutralizes every category of pollutant in your home,
including odors, without the need for filters!
Advantages: removes every category of pollutants when combined with
negative ions and UV light technologies; no filters needed; inexpensive.
Disadvantages: only available from one manufacturer.
