Top Ten Air Purifier Questions
1. Do I really need an air purifier in my home?
It depends on several factors, including your own comfort level and what the
indoor air quality is in your home. There are several factors to take into
First and foremost, many health organizations agree that indoor air quality
is often worse than outdoor air quality. In fact, for many people, indoor
allergens and irritants such as dust, smoke and pet dander may be two to five
times as bad in their homes as outdoors!
There are several indications that you may benefit from an air purifier in
your home. Reasons to get an air purifier include:
- Allergy symptoms such as itchy, watery eyes and runny nose
- Itchy, dry skin or frequent skin rashes
- Asthma or other breathing problems
- Being or living with a smoker
- Owning indoor pets
- Mold or mildew in your home
2. Do all air purifiers clean the same kinds of pollutants from the air?
No. Although all air cleaners clean certain particulates from the air, there are
differences in what and how they clean. Some remove dust and particulates such
as pet dander and smoke very effectively, while others will actually eliminate
bacteria, viruses and molds and mildew. But very few will do all of these
things, so be sure to read the article Understanding Air Purifiers for a more
detailed outline of what each type can and can’t do to improve the air quality
in your home.
3. How do I know what size air purifier to get for my home?
Actually, most air purifiers are designed for individual room use rather than
for the whole home. Unless you have an air purifier or air filtration system
that has been installed on your heating or air conditioning unit, you should get
separate units for each room or living space.
The reason you need separate units for each room is because effectiveness is
affected by air flow, and walls mean no air circulation. Each room will need its
To determine what size you need, look for the CADR number. This number indicates
the Clean Air Delivery Rate, which should always equal at least 2/3 the total
square footage of the room you will be using the air purifier in. For example, a
10′ X 12′ room has 120′ square feet, and needs a purifier with a CADR number of
at least 80.
4. What is Ozone and is it safe for indoors?
Ozone is a tasteless, colorless gas made up of three oxygen atoms. It can be
found in the upper atmosphere and is naturally produced by thunderstorms during
It is perfectly safe indoors if kept at acceptable levels (between .02 and .05
parts per million), just like many other type of naturally occurring gasses that
aren’t harmful to us at certain levels. Ozone air purifiers have been developed
to produce the correct amount of ozone to purify the air without reaching
5. How often will I need to change or clean the filter in my air purifier?
It depends on several factors, including how large the room is and what type and
size of air purifier you have. Some will need to be changed or cleaned monthly,
others more often.
It is very important to check your filter regularly and follow the recommended
schedule the manufacturer suggests, since the efficiency of the air purifier
relies on proper maintenance.
6. What exactly is a Micron?
A micron is a measurement of the size of a particulate in the air. One micron is
1/25,400 inch (roughly 100 times smaller than a single strand of hair).
Obviously, a micron is far too small to be seen. For the purpose of choosing an
air purifier, most types are considered very efficient if they can filter
airborne pollutants to .3 microns.
7. How much should I pay for an air purifier?
It’s very hard to determine what you should spend on an air purifier, because
price doesn’t always guarantee quality. Doubtless you should be willing to spend
enough to get a high-quality product, but protect your investment by making sure
your air purifier comes with a warranty.
When buying an air purifier, also take into account the cost of any replacement
filters and the electricity to run the unit.
8. Will an air purifier be noisy?
An air purifier with a fan in it will have some noise. HEPA filters, for
instance, have fans to pull the air through the filter itself, although improved
casings and quieter fans have been developed for noise reduction.
Ionic and ozone units don’t usually have a fan because they use an electrostatic
charge or ozone, so they are completely silent. If they combine their technology
with a filtration system or a fan to boost air circulation over the plates,
their will be some sound, but this will be minimal and these fans may be shut
off when you wish.
In general, the noise level of even an air purifier with a fan is low enough
that it isn’t intrusive.
9. What rooms should I put an air purifier in?
The rooms you use the most are the most important rooms for air purifier use.
Your living area, such as a family room or den, should have an air cleaner,
especially if you have allergies or pets that are in the room regularly, or if
anyone in the household smokes.
Bedrooms are also a good idea, since allergies and irritants can disturb our
sleep. Clean, fresh air has been proven to produce more restful sleep and reduce
night breathing problems while sleeping such as stuffiness, post-nasal drip and
Finally, consider getting an air purifier in the bathroom, where odors, mold and
mildew are prone to linger. An air cleaner in here can not only make it fresher
and more pleasant, but reduce the amount of mold and mildew in the air so that
your bathroom will be less of a breeding ground for germs.
10. Where in each room should my air purifier be located?
For any air purifier, it is most important to locate it near the most activity
or traffic flow so that there is plenty of air circulation around the air
filter. This will increase the air exchange rate and make the air cleaning more
With a HEPA filter, it is best to locate it near an open area to ensure air
movement all around. For an ozone air purifier, you should try to locate unit
higher rather than lower, since ozone molecules are heavier than oxygen and will
tend to drift downward. The same logic applies to ionic air purifiers, which
release charged particles into the air.
If your air purifier unit is relatively portable and you have someone in the
room who is a heavy smoker, move the air purifier a bit closer to him or her if
this is practical (and if it won’t mortally offend them!). You may also want, on
occasion, to move the máy lọc không khí to a specific room when you have a particular
odor to get rid of (you burned dinner, etc.).