16 Air Purifiers Most Frequently Asked Questions

When purchasing air purifier there are lot of questions that potential buyer has. In this article I will answer air purifiers most frequently asked questions.

Did you know that most Americans spend up to 90 % of their time indoors? According to the Environmental Protection Agency (EPA), indoor pollutant levels may be 2-5 times higher than they are outdoors and occasionally even 100 times higher!

Your home’s air can be affected by a variety of pollutants including pollen, mold, dust, dust mites, pet dander, tobacco smoke, etc.

The EPA also reports that exposure to these indoor air pollutants can result in wide range of health effects, from immediate to long-term illnesses and mild to severe or even fatal symptoms.

Using an air purifier to remove impurities and deliver clean air to your home is a great solution for proactively minimizing your risk and exposure to indoor air pollution.

However, there are tons of air purifiers on the market, so how do you pick the best air purifier or even know what to look for? Start your search here by getting answers to the most common questions we receive about air purifiers.


Air Purifiers Most Frequently Asked Questions

How do I know if I have an indoor air quality problem?

The Environmental Protection Agency suggests monitoring your health effects after a change in your surroundings.

For example, if you have new health problems after moving, remodeling, refurnishing, or a performing pesticide application, this could be an indicator of an indoor air quality problem.

Another way is to identify potential sources of pollution, such as toxic household cleaning products, tobacco smoke, pets, pressed-wood products, combustible heaters…

Check areas of your home that may have poor ventilation. Look for smelly or stuffy air, condensation on walls or windows, or mold growth around your home.


What are the best air purifiers for allergy and asthma sufferers?

Air purifiers that use HEPA filtration are the best choice because they remove up to 99.97% of allergens up to 0.3 microns in size from your environment.

The IQAir HealthPro Plus and the Austin Air Healthmate are all excellent choices for sufferers of allergy and asthma symptoms.

These units feature multi-stage air filtration, which includes a particle pre-filter, a HEPA filter, and a carbon filter.

Browse more recommended air purifiers for these conditions on our compare air purifiers page.

Additionally, people with asthma should avoid using ionizing air purifiers. Some models emit ozone, which can harm indoor air quality and aggravate asthma and other respiratory problems.

The vast majority of ionic air purifiers produce little to no harmful ozone, making them safe for use in homes.

However, it is a good rule of thumb for asthma-sufferers, in particular, to avoid using ionizers in general.


What are the different types of filters?

To assist with cleaning your air, air purifiers use air filters. There are three main types of air filters:

1. HEPA Filters – High-Efficiency Particulate Air (HEPA) filters remove 99.97% of particles that are 0.3 microns and larger from the air.

This makes HEPA filters ideal for removing small pet dander particles, dust mite residue, and pollen from your air.

2. Carbon Filters – Using activated carbon, these filters remove odors and chemicals your indoor air.

These odors and chemicals include cigarette smoke, fireplace fumes, formaldehyde, volatile organic compounds (paint fumes, carpet glues, new building materials, etc.), pet odors, and kitchen odors.

3. Pre-Filters – These filters are a great benefit because they help extend the time between filter cleanings or changes as well as maintain the air purifier’s functionality and efficiency.

Pre-filters do this by trapping large particles before they reach the main filters of the air purifier.


How much maintenance is required for the air filters?

This varies from air purifier to air purifier. Most air purifiers have 2-4 filters.

For the majority of air purifiers, filters should be cleaned occasionally and changed every six to eight months for optimum results.

Some models feature permanent air filters that never need changing. Others have a combination of washable and replaceable air filters.

To help maintain the life of your air purifier, many models include filter indicator lights.


What happens if the air filters are not changed?

With dirty or old air filters, your air might not be getting filtered thoroughly. That could result in poor air quality and increased risk of allergy, asthma, and other respiratory problems.

Clean or replace air filters to ensure that your air purifier is performing best.


What does CADR stand for?

A: This acronym represents measurement for air purifiers. CADR stands for Clean Air Delivery Rate.

This measurement was developed by the Association of Home Appliance Manufacturers. It indicates the volume of filtered air delivered by an air purifier.

It is given in three measurements. One for pollen, one for tobacco smoke, and one for dust. The higher the CADR number, the faster the unit filters the air for that particular particle.


What does ACH stand for?

ACH stands for Air Changes per Hour. This indicates how frequently the air purifier filters or changes all of the air in a given space per hour.

For example, an ACH rating of 7 means that all of the air in your room is thoroughly filtered seven times per hour. ACH rating of 5 or 6 is recommended for healthy indoor air.

For individuals with allergies and asthma, an ACH rating of 6 or 8 is best.


What does CFM stand for?

CFM stands for cubic feet per minute. This measurement represents how many cubic feet of air move through the unit per minute.

This is important when considering which air purifier is right for you. The higher the CFM, the better potential air purification results.

CFM can be impacted by a variety of factors. That includes fan speeds, insulation, air flow in the room, furniture in the room, and the amount of pollutants in the air.

There is an equation to help you determine an ideal CFM. To find your ideal CFM, calculate the total volume of your space (length x width x height in cubic feet) and divide this number by your desired ACH.

Here is a sample equation:

CFM  =

18 ft x 24 ft x 8 ft
5 (air exchanges)





What is a micron?

Short for micrometer, a micron is one millionth of a meter and approximately 1/25,000th of an inch.

Microns are used to measure airborne particle sizes. This is important because many harmful airborne particles are invisible to the naked eye, making them easily inhaled or distributed throughout your indoor environment.

For example, dust mite allergens can be as small as 0.1 to 0.3 microns, which is considerably smaller than a single strand of human hair that typically measures 30 to 120 microns.


Do all air purifiers clean the same type of pollutants?

People use air purifiers for a wide range of reasons. There are air purifiers that remove smoke, pet dander, pollen, and even chemicals.

For the most thorough particle filtration results, look for air purifiers with true HEPA filters.

If you want to address odors and chemicals, look for models with carbon filters. To combat airborne germs, newer models are now being equipped with internal ultraviolet lights, in addition to traditional filters.


Are air purifiers loud?

The loudness of an air purifier is measured in decibels. It depends on a few factors. Those factors include a model of air purifier, the fan operating speed, and personal noise tolerance.

Air purifiers manufactured by Blueair are known to be much quieter than other comparable brands.

Most air purifiers feature multiple cleaning speeds. Air purifiers are likely to be loud on the highest speed. Noise is subjective and what might be intolerable to you might not be as loud to someone else.


How long should I run my air purifier?

For best results, it is recommended to run your air purifier continuously. To help with noise and electricity costs, most air purifiers come with multiple cleaning speeds.

While you are away from home, your air purifier can be on a lower setting. This saves energy and cuts costs while still maintaining a clean environment.


Is it expensive to use an air purifier?

This differs among air purifiers. Some are much more energy-efficient than others.

HEPA air purifiers typically consume 50 to 200 watts of electricity. To put this into perspective, a lamp uses approximately 60 watts, and a computer uses 365 watts.

Using an air purifier probably isn’t going to impact your electricity bill tremendously. However, if this is a top concern in your search for an air purifier, consider an Energy-Star rated air purifiers, such as the Whirlpool Whispure 510 Air Purifier.


Where should I place my air purifier?

Most air purifiers are designed to clean single room. It’s best to put an air purifier in the room you spend the majority of your time in.

For most people, this is the bedroom. However, you may also spend many hours in a home office or a living area with your family.

You may want to consider purchasing an air purifier with caster wheels that allow you to easily move the unit from room to room to gain clean air anywhere that you spend your time.

Some air purifiers also have a carry handle or are very light-weight so moving from room to room is not a problem.


How much space will an air purifier cover?

Air purifiers are designed to fit a variety of spaces. Find an air purifier that fits both your CFM and ACH needs, as well as the size of the room where the unit will be primarily used.

Most manufacturers will provide a suggested room size to receive the best results from that air purifier model.


Which air purifier is best for me?

This depends on multiple factors including the condition you want to treat, square footage, CADR rating, the frequency of filter replacements, type of controls, and much more.

Ultimately this choice is a personal one, which is why we supply you with the best information to make an informed decision when choosing an air purifier.

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