Q: What are the different types of filters?

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

  • 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.
  • Carbon Filters: Using activated carbon, these filters remove odors and chemicals from 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.
  • 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.

Air Purifier Replacement Filters

Q: How much space will an air purifier cover?

A: Air purifiers are designed to fit a variety of spaces, from large to small. Make sure you look at the square footage of the room it will be primarily used in. Then consider your CFM and ACH needs. Most manufacturers will provide a suggested room size to receive the best results from that air purifier model.

Q: Where should I place my air purifier?

A: Most air purifiers are designed to clean single rooms, so naturally, it's best to place an air purifier in the room you spend the majority of your time in. For most people, this place is the bedroom. However, you may also spend a bulk of your hours in a home office or a living area with your family. Moreover, children may make frequent use of a dedicated play area. It's beneficial to create clean air in these environments as well. You may want to consider purchasing an air purifier with caster wheels that allows you to easily move the unit from room to room to gain clean air anywhere that you spend your time.

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

A: The EPA 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. Consult your family physician. Another way is to identify potential sources of pollution, such as toxic household cleaning products, tobacco smoke, pets, pressed-wood products, combustible heaters, and many more. Also, identify 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.

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

A: Proper air filtration is crucial for homes of allergy- and asthma-sufferers, since allergy and asthma triggers can easily find their way into homes, despite your best attempts. Air purifiers that use HEPA filtration are the best choice for sufferers because they remove up to 99.97% of allergens up to 0.3 microns in size from your environment. Additionally, asthma-sufferers should avoid using ionizing air purifiers because 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.

Q: What air purifiers are best for pet dander?

A: Ridding your indoor air of pet dander and odors is crucial, especially when you love your pets. Pet dander consists of several allergens that aggravate sensitive immune systems, including pet saliva, dead skin cells, and even outside particulates brought in by your pet on their coat. These factors or allergens trigger those allergies and, more often than not, are dispersed throughout your indoor air and on furniture.

Q: How much maintenance is required for the air filters?

A: This varies from air purifier to air purifier. Most air purifiers have two to four filters. For the majority of air purifiers, filters should be cleaned occasionally and changed every six to eight months for optimum results. However, 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. Read product descriptions and manufacturer literature to determine if the air purifier you are interested in has a filter indicator light.

Q: What happens if the air filters are not changed when the indicator light comes on?

A: With dirty or old air filters, your air might not be getting filtered thoroughly, resulting in poor air quality and increased risk for allergy, asthma, and other respiratory illness symptoms. To ensure that your air purifier is performing its best, clean air filters are crucial. Change them when indicated.

Q: What does CADR stand for?

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

Q: What does ACH stand for?

A: 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 6 means that all of the air in your room is thoroughly filtered six times per hour. We recommend an ACH of 5 or 6 for healthy indoor air. For individuals with allergies and asthma, an ACH rating of 6 or 8 is best.

Q: What does CFM stand for?

A: 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.

Keep in mind that CFM can be impacted by a variety of factors, including fan speeds, insulation, air flow in the room, furniture in the room, and the amount of pollutants in the air. However, there is an equation to help you determine an ideal CFM, which can provide help when deciding on air purifiers.

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. Below is a sample equation:

CFM  =

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





Q: What is a micron?

A: 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.

Q: Do all air purifiers clean the same type of pollutants from the air?

A: People use air purifiers for a wide range of reasons, from basic air cleaning to high volume allergen removal for allergy- and asthma-sufferers. 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.

Q: Are air purifiers loud?

A: The loudness of an air purifier (measured in decibels) depends on a few factors such as the model of air purifier, the fan operating speed, and personal noise tolerance. Most air purifiers feature multiple cleaning speeds. Thus, if your air purifier is operating at its maximum cleaning speed, it will be louder than if it is operating at a lower speed. Keep mind, however, that noise is subjective and what might be intolerable to you might not be as loud to someone else.

Q: How long should I run my air purifier?

A: For best results, it is recommended to continuously run your air purifier. To help with noise and electricity costs, most air purifiers come with multiple cleaning speeds. For example, to maintain your indoor air quality while you are away from home, your air purifier can be on a lower setting than when you are home. This saves energy and cuts costs while still maintaining a clean environment.

Q: Is it expensive to use an air purifier?

A: This is another situation where the answer lies within the differences 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 purifier or find out how many watts an air purifier actually uses before purchasing it.

Q: Which air purifier is best for me?

A: This depends on multiple factors including the condition you want to treat, square footage, CADR rating, 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.