What the best air
- HEPA filtration. HEPA filtration is regarded by experts as the most effective type
of filtration for removing allergens and small particles from the air. Other
filters are designed to mimic this effectiveness, but few achieve the ability
to remove particles down to 0.1 microns in size or smaller.
- High maximum air-exchange
rate. Maximum air-exchange rate refers to the
amount of air an air cleaner is capable of passing through its system in a
minute. Air purifiers with higher maximum air-exchange rates will clean the air
faster than those with lower rates.
alert. Many air purifiers come with a counter to let
you know when it's time to change the filter. Some operate on a daily-countdown
basis, while others actually base this information on the state of the filter.
- Dust sensor or
air-quality monitor. A few air
purifiers have automatic sensors to detect how polluted the air is, with the
ability to adjust the purifier's cleaning speed accordingly without manual intervention.
This, of course, provides users with less precise control over energy
consumption and noise levels, but it's a useful feature if you'll be using an
air purifier in a non-occupied space.
- Several fan speeds. Most air purifiers have multiple fan speeds, which adjust the
speed at which the air is cycled through the unit. There's a direct correlation
between higher fan speeds and more noise, however.
- Large capacity. If you need an air purifier for a small space, more affordable
options are practical. But for larger rooms, you'll need to purchase a more
expensive model capable of handling more square footage.
- Reasonable cost of
ownership. Most air
purifiers have long-life filters that must be replaced every three to five
years. Some models have more than one filter, while others come with a
permanent filter meant to be vacuumed periodically instead of replaced. The
more frequently you have to replace the filter, the more it will cost you over
- No or very low
ozone. Experts say that ozone is effective in
neutralizing odors and chemical gases. They also say that this is a classic
case where the cure is worse than the disease as high-levels of ozone can be
toxic. If you opt for an electronic air purifier, chose a design that emits low
or, better still, no ozone. Skip ozone generators sold as air cleaners
Know before you
Do you want a whole-house or room air purifier? Experts say that a room air purifier might not be necessary for
most individuals. Some owners say they've experienced significant relief from
allergy symptoms with the use of a $25 furnace filter that works with an
existing household unit.
Do you have severe allergy or asthma
symptoms? Owners and experts agree that for individuals suffering from severe
allergy or asthma symptoms, the investment in top-of-the-line air purifiers is
worth it. But if you suffer from only mild symptoms or simply want to reduce
smoke or pet dander in your home, a more affordable model can do the trick.
How much space do you have? Air
purifiers can be heavy and bulky, with some requiring a few feet of clearance on
all sides. Be sure to measure your available space and allow for all space
considerations before you buy.
What room will you use an air purifier in? If you're planning to use an air purifier in your bedroom, for
instance, you'll want to choose a model with a noise level that you can
tolerate while sleeping. In living spaces, choose an air purifier with
adjustable speed settings so you can turn it up to a higher setting when you're
not in the room to be disturbed by the noise.
Value expectations: The dollars and
cents of it
Air purifiers aren't cheap to own. Many cost
several hundred dollars up front, and most replacement filters are fairly
expensive -- some cost as much as $100 for the HEPA filter, with additional
costs for prefilters and carbon filters. Some air purifiers require more
frequent filter replacements, which adds to the cost over time. Owners suggest
purchasing multiple filter packs online to save money. For those suffering from
severe allergies or asthma, the cost is often worth it, and you may be able to
purchase it with FSA funds with the proper documentation from your medical professional.
Others should try more affordable options, such as furnace filters, which cost
significantly less and can be just as effective for most people. While there
aren't a lot of complaints about malfunctioning air purifiers, many models
offer warranties of five years for peace of mind. Also, keep in mind that if
you can hunt down and eliminate sources of allergens and odors, you might be
able to do without an air purifier altogether.