Choosing the Best Air Purifier: FAQ

An air purifier is an appliance that reduces the concentration of airborne contaminants in a designated area according to the specifications of the particular product. Purifiers help to clean indoor air, which is helpful to people who suffer from allergies, asthma, chemical sensitivity, and other respiratory-related symptoms.

Learn more in our Air Purifier Buying Guide.

An “air cleaner” is another term for an “air purifier.” Both are designed to remove indoor air pollutants and particulates. When these types of appliances first came on the market, they were typically called air cleaners, but in recent years, they are primarily referred to as an air purifier.

There are portable room air purifiers, designed to clean a specific-sized room, and there are whole-house installed air purification systems that work with the HVAC system in a home. A portable room air purifier is the least expensive way to significantly reduce indoor air pollution.

Portable room air purifier models are typically categorized based on their cleaning technology: HEPA filtration, electrostatic precipitation, and negative ion generation. Some air purifier brands use a combination of these technologies. There are also air purifiers which are designed just for chemical removal. In addition to airborne particles, some air purifier lines also have technologies, like ultraviolet light, which remove viruses, bacteria, fungi, volatile organic compounds, odors, and some gaseous chemicals. Activated carbon blends and a variety of other substances may be used to capture gases and odors.

HEPA (High Efficiency Particulate Air) filters are well proven filtration devices that continue to be enhanced by many manufacturers. The benchmark for air filters, HEPA filtration guarantees the air purifier will trap 99.97% of particles larger than 0.3 microns. For more information, read What is a HEPA Filter.

The human eye can’t see a particle smaller than 10 microns so many of the particulates captured cannot be seen, particularly bacteria and viruses. The filters found on room air conditioner models capture only large particles greater than 10 microns. For the smaller particles like dust, smoke, chemicals, pollens, and asbestos, HEPA filtration is needed in an air purifier.

For many years, HEPA air filters have been used in air purifiers to filter particles. HEPA filters are well proven filtration devices and continue to be enhanced by many manufacturers. HEPA filtration guarantees the purifier will trap 99.97% of airborne particles larger than 0.3 microns. The human eye can’t see a particle smaller than 10 microns so many of the particulates captured cannot be seen, particularly bacteria and viruses. The filters found on room air conditioner models capture only large particles greater than 10 microns. For the smaller particles like dust, smoke, chemicals, pollens, and asbestos, HEPA filtration is needed.

The HEPA filtration component is essentially an accordion of very, very fine paper-like filter material. The material is loaded in an accordion or zig-zag fashion so that a very large surface area becomes available for air to be pushed through by the fan. Over time, the HEPA filter will become full and the airflow will no longer be able to move through the filter. HEPA filters typically last a number of years.

The more times the air in a room passes through a purifier with HEPA filtration, the cleaner the air will become. For the air purifier to be effective, it is important that it have the cleaning capacity for the size room in which it will be used. The specifications on the product will indicate what size room it is designed to clean. Read more about HEPA Technology.

Electrical attraction is another technology used by air purifier appliances to trap airborne particles. There are three types of products that use this technology: electrostatic precipitating cleaners, electret filters, and negative ion generators.

Electrostatic precipitating (also called “electronic” air purifiers) draw particles into the unit via a fan and charge them with a series of high-voltage wires. Several plates (the precipitating cells) carry the opposite electrical charge and attract the contaminants as they pass by the plates, thus trapping them. They are typically not as effective as HEPA, removing 95% of airborne particles as opposed to 99.97% in a HEPA air purifier.

Electret filters use synthetic fibers to create static charges to attract particles.

Negative ion generation is a technology that is sometimes used as the sole cleaning agent, or in conjunction with HEPA filtration in an air purifier. Negative ions are emitted into the air and attach to the positively charged particles in the room, then clumping together to settle out of the air onto a surface. Read more about air purifier technology.

In a quality, non-ozone producing air purifier, there won’t be any side effects other than improved health. AirPurifiers.com only sells purifiers that emit clean air into the room. We do not offer products that emit odor, chemicals, or harmful ozone into the air. For people who are chemically sensitive, it is also important that the unit itself be constructed of materials which won’t off-gas.

Although studies vary depending on the source, it has been proven time and time again that indoor air is often dramatically more polluted than outdoor air. The EPA (Environmental Protection Agency) and other U.S. government agencies can be contacted for the most recent numbers.

AirPurifiers.com receives more questions about air purifiers for mold than just about anything else, followed by how to relieve allergies. Airborne mold spores are extremely small and can pass by the cilia in the sinuses. Since mold spores are too small to be exhaled, they can become lodged within the lung tissue of the body. Mycotoxins, the product of mold metabolism, are even more toxic.

It is important to remove concentrations of mold in the home, as it is very hazardous to your health. Although an air purifier will remove any airborne mold particles, if the mold is present on surfaces in high concentrations, it should be professionally removed.

Dust particles, while unpleasant to see, are not as much of a health issue as the smaller particles that get past the body’s barriers. “Dust bunnies” are composed of dust mites and their fecal material, skin cells, mold spores, pollen, and other unsavory ingredients. It is critical to clean and vacuum regularly to remove dust bunnies and large dust particles. However, particles become airborne during vacuuming, so it is helpful to run an air purifier on the highest speed as cleaning progresses. Running an air purifier in your home continuously will help minimize the presence of dust. Visit Health + Home to learn more about air purifiers and dust.

Gone are the days of rehoming beloved pets due to allergies. A quality air purifier helps to dramatically reduce pet dander and odor, especially if placed near where the pet spends a lot of time.

If there are pets in the home, it is important to utilize air purifiers. For example, cats lick their fur, and once the saliva dries to a fine dust, it becomes airborne. Similarly, pet birds shake their feathers, and the super fine dust becomes airborne. Pets also track in allergens from the outdoors which can be removed by an air purifier. The odors associated with urine can also be removed by an air purifier with activated carbon. Visit Health + Home to learn more about air purifiers for pet dander.

First, identify your air quality problem. Are you concerned about smoke, dust, mold, pet dander, or asthma? Air purifier brands vary greatly in their effectiveness for different problems. For general purpose air cleaning, any of the air purifiers on AirPurifiers.com will meet your needs. Many of our customers complain of morning congestion, which can be remedied by keeping a HEPA air purifier in the bedroom. A moldy basement will require a different purifier that can remove both the airborne mold spores and the musky odor. A home with pets will need a purifier that can catch the dander, and a home with a smoker will need an air purifier with activated carbon. Identify the problem, determine the best technology for the problem, and choose the right model for the room size. For more information on how to get started, see our official Air Purifier Buying Guide.

There is no cookie cutter approach when it comes to cleaning the air in your environment. The quality brands offered on AirPurifiers.com are all made by well-established companies and meet our rigorous testing standards. The best air purifier is the one that solves your problem. We invite you to read our real customer reviews and ratings to help with your search.

To learn more about how we test and rate purifiers, see our Air Purifiers Ratings Guide.

The type of air purifier you need depends on the size of the area to be cleaned and what you are trying to remove from the air within that area. Is it pollen, dust, smoke, or chemicals? We carry purifiers for every need and for a variety of room sizes. Not sure where to start? Read our Air Purifier Buying Guide.

There are two cost considerations for long-term air purifier maintenance: power consumption and filter changes. Generally, a higher quality purifier is engineered to be energy-saving and uses minimal electricity.

Filter requirements vary by brand. Some brands have monitors that indicate when the filters should be changed, while others stipulate the number of months a filter should last. In general, the HEPA filters last a number of years, whereas activated carbon filters will need to be changed sooner. It is important to change a pre-filter (which captures the larger pieces of dust and dander) according to the manufacturer’s recommendation.

Although a filter less purifier may initially seem more affordable, there are several considerations. First, filter less purifiers are typically less effective as a purifier with HEPA filtration. Secondly, without regular cleaning of the filters, their effectiveness is greatly diminished.

Filter less purifiers use electrostatic precipitation technology. A well-maintained filter less purifier can collect large particles, such as dust and dander, but fails to capture smaller particles found in smoke, molds, and chemicals. Some electrostatic purifier models produce harmful ozone as a by-product. There are many quality air purifier models available that are ozone-free and more appropriate for home use.

There is no “one size fits all” when it comes to effective indoor air cleaning, but filter less purifier units tend not to address specific concerns. It is best to have an air purifier with the appropriate filters for the allergens or chemicals that need to be removed from your indoor environment. Read more about air purifier technology.

Every air purifier on AirPurifiers.com comes standard with filters.

Ideally, there should be a unit in the bedroom and one in the most high traffic area of your home, like the living room. It is particularly important to sleep in a clean room. The respiratory system slows down at night and it can be more difficult to breathe easily if the air quality is low. The cleaner the sleeping room, the better the sleep. In a very large space, such as your main living area, it is more effective to use multiple small units rather than one large one. This will enable you to operate the air purifiers at the lower quieter speeds.

Purifiers are portable and easily moved from room to room. For a lower maintenance option, designate an air purifier to each room thereby creating a whole house solution for cleaning your indoor air.

The decibel level of an air purifier varies with the speed. Most are fairly loud on the highest speed. It is wise to run the purifier on high when you are not in the room. The highest speed will enable it to pull the air in from the farthest areas of the space. On lower speeds, air purifiers are much quieter. In general, silent purifiers do not move much air and are thus less effective.

Within a day after installation, the room should be noticeably cleaner. Breathing should be easier. Morning congestion and allergy symptoms should be lessened. The air in the room should no longer feel heavy. Some brands even have electronic monitors that signal when the filter should be changed. Once you change a dirty filter, you’ll see clearly that the purifier is working.

The air purifiers offered on AirPurifiers.com are designed to run continuously. An air purifier cleans most efficiently and operates most cost-effectively when run uninterrupted.

You may order replacement filters on our site or by calling us at 800-497-8263.

Filter changes depend on the brand and the model. Some air purifier models feature electronic indicators that tell you when to change the filters. Others designate a time period that the filter is intended to last.

In general, air purifiers are designed for quick and easy filter changes. Replacement filters come with instructions or you can contact us for assistance.

We only offer brand new products on AirPurifiers.com.

As the Consumer’s Guide to Air Purifiers, we want to offer consumers as much information as possible to make informed decisions. After nearly two decades of testing air purifiers, our goal is to share research and empower consumers.