Buying Guide
11 Critical Factors to
Consider When Buying an Air Purifier
For more help in making your
decision, also read Frequently
Asked Questions, Choosing
the Right Model and Compare
Technology.
1. Effectiveness (Particle Size Removal
Capability)
Most
HEPA air filters (the most effective type of
filter, not air purifier) can remove 99.97%
of particles as small as 0.3 microns from the air. However, most
airborne allergens and contaminates are smaller than the 0.3
microns a HEPA air filter is capable of removing (See Common
Airborne Particles and Their Sizes in Microns). HEPA
air filters can remove smaller particles, but not very effectively
or consistently.
Electronic air cleaners that
utilize negative ions and low-level ozone
(negative ion generators and ozone generators) are able to remove
particles as small as 0.01 microns from the air, which is smaller
than many airborne pollutants, but not all. BiozoneÆ
Air Purifiers are able to remove particles as small as 0.001
microns, which includes viruses, typical atmospheric dust, pesticides
and herbicides.
To gain an understanding of the
importance of the difference in particle size removal ability
between air filters, ozone/negative ion/UV light air cleaners
and Biozone, you need to consider the size of some of the most
common indoor air pollutants.
For instance, fumes and viruses
are too small to be captured by any air filtration device.
Negative ionization can remove many of the fumes and viruses.
Very few tobacco smoke particles are large enough to be captured
by filters, but most of these are large enough to be removed
by ozone and negative ions.
Some dust mites and bacteria
are large enough to be captured by HEPA air filters, but most
(all bacteria) are able to be removed by ozone and negative ions.
A HEPA air filter can capture
most mold spores and pollen that pass through them, while ozone
and negative ions can remove all that they come in contact with
from the air, since they are emitted throughout a room or area.
Biozone
Scientific has developed a scientifically advanced technology
termed PureWave™
that combines the science of ultraviolet germicidal
lightwaves, purifying hydroxyl radicals, activated
oxygen and photo-ionization. What makes this technology important
and unique is that it unites four of the most accepted and powerful
methods for destroying (not just filtering) contaminants up to
.001 microns, with the resulting synergy producing a stronger
process than the sum of the individual methods.
While most manufacturers of ozone
air purifiers use the older, corona discharge
(high voltage electricity) method to create ozone, the PureWave™
technology uses special, patented ultraviolet lamps that produce
photolic ozone as well as certain wavelengths
of light that control ozone levels. Along with these functions,
the lamps also produce ultraviolet germicidal irradiation (UVGI),
which, like ozone, destroys bacteria, viruses and fungi and has
been used in medical facilities for years for those exact purposes.
As you will see in the categories
below, the effectiveness of a filtration device is also limited
by the simple fact that most airborne particles will not pass
through any given location in a room, such as where the filters
is placed.
2. Method of Purifying
Air
Many
air purifiers are hampered by severe limitations. Air cleaners
that rely on filters, such as HEPA units, can only clean the
air that is nearby, leaving most of your house, or even a single
room, unpurified. Only a very small percentage of the air in
just a single room will find its way through a stationary filter.
See Biozone Air Purifier versus HEPA Air Filters.
Air filters can also serve as
a breeding ground for mold and bacteria. The dust that is also
collected provides these microbes the nutrients they need to
thrive. Filters can also spread illness when you handle the filters
for maintenance and replacement purposes.
Even if you eliminate a HEPA
air filter from consideration, it is still important to realize
that all negative ion and ozone generators are not alike. Due
to maintenance requirements, many electronic air cleaners use
a fragile glass plate that could easily break. Glass plate technology
also means lower reliability due to the fragility of the glass
plates themselves, and also because they need to be cleaned frequently
in order to work properly. Biozone® Air Purifiers do not
use plates.
There are three ways an air purifier
can actively produce negative ions: by high voltage electricity
run through metal needles (needlepoint ionization),
or passively, as a byproduct of when ozone is created by corona
discharge or UV light. Needlepoint
ionization is by far the most effective way to produce high volume
negative ions. However, negative ions have a very short life
(2 - 6 minutes) and die before they can circulate completely
throughout a dwelling. Also, a high-powered ion generator will
produce what has been termed "black wall", a black
dust that settles on surfaces, in particular around the ion generator.
Understanding the limiting factors of negative ion production,
the Biozone units ultraviolet light produces enough negative
ions to be beneficial in removing airborne particulates in a
surrounding area and in helping change the ion balance in that
environment, but without creating black wall.
If the negative ions are only
being produced as a byproduct of creating ozone, only a small
amount of negative ions will be produced. As a result, with this
method you will not see much improvement, if any at all, in the
airborne particulate/allergen level.
Also remember, negative ions
cannot be transmitted "through" walls. The FTC has
disallowed such claims.
See a comparison of Biozone®
Air Purifiers versus Other Negative Ion / Ozone Generators.
3. Square Foot Coverage
/ Cost per Square Foot
Remember,
a low price does not mean cost efficient. Many lower-priced air
cleaners are actually costly when it comes to cost per square
foot cleaned, the true measure of an air purifier's value. Most
HEPA air filters are rated to cover 1000 square feet or less,
although they are typically similar in cost to ozone and negative
ion air cleaners that can cover much larger areas.
To calculate the cost per square
foot cleaned, simply divide the electronic air cleaner's square-footage
coverage by its cost. You may also want to factor electricity
consumption and replacement costs into your calculation to get
a more accurate idea of "cost of ownership" and "true
value provided".
4. Whole-Home or Whole-Office
Building Coverage
A
single air purifier can rarely purify an entire home or office
building regardless of how many square-feet it is rated to cover.
This is due to the fact that walls, floors, ceilings, doors,
etc. serve as barriers for air purifiers, even for those that
use negative ions and ozone.
The best way to thoroughly purify
the entire home is to use multiple air purifiers throughout the
home, so each part of the home is within reasonable range of
an air cleaner. However, this approach can be cost-prohibitive
with most air purifiers. One exception is the Biozone line of
air purifiers, which make it affordable to buy multiple air purifiers.
Click here for more information on Biozone®
Residential and Office Air Purifiers.
In-duct units can also provide
exceptional air purification for your home or office. Biozone® In-Duct
Air Purifiers are designed to be installed directly
into the existing central heating and air conditioning ventilating
system's ductwork. They turn any central heating and cooling
system into an air-cleaning machine to significantly reduce pollutants
and contaminants in homes and businesses.
5. Replacement Parts
Cost & Maintenance
Many
air purifiers will actually cost more in replacement costs for
parts such as air filters in a single year than their original
purchase price. Be particularly aware of air cleaners that use
air filters. Air filters generally last about three months, and
in many cases cost a couple hundred dollars to replace.
As has been mentioned before,
negative ion & ozone generators using glass plates require
frequent cleaning and maintenance. Plus, these glass plates break
very easily, and often need to be replaced. Ceramic plates are
much less susceptible to damage, but they are still vulnerable.
Biozone doesn't have any filters or plates to mess with because
of their scientifically advanced PureWave™
technology. The only maintenance on a Biozone unit is to replace
the relatively inexpensive UV light every 12 to 15 months, and
to wipe the bulb with a damp cloth every few months if there
is heavy pollution in the room.
6. Strong Odor Removal
If
your primary need for an air purifier is to eliminate or reduce
an odor, then an air cleaner that uses ozone will be necessary.
Air filters are not capable of removing most particles that cause
odors, but ozone can destroy most odor-causing particles.
Negative ion-only air purifiers
are not very effective at removing odors either. They can help
reduce odors to a degree, but are mostly effective at removing
solid particles such as dust, pollens, animal dander, etc. If
a negative ion air purifier also uses ozone, then it will be
effective at removing odors.
For odors, it is best to have
an air purifier that automatically produces safe levels of ozone
so that the unit does not create harmful ozone levels that exceed
safe levels. Biozone air purifiers have this capability -- SafeZone™ --
making them perfect for stronger odors, including cigarette smoke.
7. Electricity Costs
It
is also important to find out how much an electronic air cleaner
will cost in power consumption, since some can cost over $300
per year in electricity. To determine annual electricity cost,
find the number of watts listed by the manufacturer of the air
purification system you are considering and use the following
equation to determine the annual cost in electricity needed to
run the air purifier.
(Watts/1000)
X (KWH-Kilowatt Hours) X (8760) = Annual Electricity
Cost
Example:
1. Divide
the number of watts listed by the manufacturer by 1000. For instance,
a Biozone 1000 uses 11 watts:
- 11 divided by
1000 equals 0.011
- 2. Multiply the result by the number of
Kilowatt Hours (KWH) you are charged by your electric utility.
You can find this on your electric utility bill, or you can use
0.10, which is typical.
- 0.011
- x 0.10 KWH
- ------------
- = 0.0011
- 3. Multiply the result by the number of
hours the unit will run on an annual basis. Unless the contamination
level is extremely low, you will want to run your air purifier
continually, so 8760 (24 hours times 365 days).
- 0.0011
- X 8760 Hours
- -----------
- $9.636
In our example, the Biozone 1000
would cost less
than ten dollars in annual
electricity cost ($9.636)
8. Noise Made by the
Fan
Many
electronic air cleaners that use air filters utilize a motor
in an attempt to draw more air through the air filter. Unfortunately,
these motors are very loud. Many negative ion and ozone generators
may also be equipped with a fan, but these fans usually make
quite a bit less noise than a fan you might place on a desk in
the middle of summer.
Biozone units are virtually silent,
especially at the lower settings. Smaller units don't use a fan
since they are only intended to cover a small room or area. Larger
units use a fan to distribute the negative ions and ozone evenly
throughout a room, but they don't need a powerful fan because
negative ions and ozone can move around a room by using the room's
natural air flow, due to their electrical reactivity with the
elements of the air. The fan in these larger units range from
5 cfm (cubic feet per minute of air movement) to 50 for the Biozone
5000 which is rated for spaces up to 5,000 square feet Compare
that noise level to some ceiling fans that use 10,500 cfm and
you can hear how quiet Biozone units are. (NOTE: The fans
on Biozone's commercial and industrial units range between 22
and 900 cfm.)
9. Warranty
Most
air purifiers on the market come with at least a 2-year warranty.
If an electronic air cleaner offers something less, this should
raise a red flag in your mind. All Biozone® Air Purifiers
come with a 3-year warranty.
10. Size & Portability
It
is a good idea to buy an air purifier that can be easily moved
from room to room. In which case, you should check the dimensions
and weight of the machine to determine if it is portable. Plus,
you may want to place your air purifier on a shelf or within
a certain spot on an end table. This is especially true since
negative ion & ozone air purifiers are more effective when
placed higher. In which case, make sure you buy a unit that is
compact enough to fit in such places. BiozoneÆ Personal,
Residential and Office Air Purifiers range in weight from the
10 ounce portable model to 8 pounds for the large 5,000 square
foot, high capacity unit, most being as small as a shoebox and
easily moved around.
11. Guarantee
Regardless
of how wonderful an electronic air cleaner may seem from what
you hear or read, you never know for sure whether it will result
in a noticeable difference in your particular environment. Therefore,
you should find a supplier that offers a money-back guarantee.
This way, you will not be out a couple hundred dollars or more
if the air purifier does not work the way you hoped it would.
Biozone's
Guarantee
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