Air Purifier Buying Guide

Last Updated May 2024

Thought your home was a safe haven from pollution and contaminants? Think again. According to the Environmental Protection Agency (EPA), the air inside our homes can actually be more polluted than the air outside. That’s right: EPA studies of human exposure to air pollutants suggest that indoor levels of pollutants may be two to five times—and in some instances, more than 100 times—higher than outdoor levels. Scary stuff considering most people spend about 90 percent of their time indoors.

And indoor air pollution is sneaky. Taking the form of microscopic particles or gasses, it comes from unsuspecting sources like cooking, cleaning, building materials and even home furnishings. Pollutants like automobile emissions, secondhand smoke, pollen and dust also filter in from outside, creating the perfect storm of indoor, airborne contaminants. And these contaminants aren’t just gross, they can cause lung irritation and trigger allergic reactions, too.

But that’s not even the worst of it. According to the EPA, long-term exposure to high particle levels is linked to bronchitis, reduced lung function and even premature death. And other research suggests that too much exposure to volatile organic compounds (VOCs), which come from paints and cleaning products, can cause nose, throat and eye irritation, headaches, nausea, and can even damage the liver, kidney and nervous system. Some gasses, such as radon, are linked to lung cancer and even death.

While regular vacuuming, dusting and cleaning can help keep some of these contaminants at bay, they don’t effectively remove them from the air. An air purifier that can remove airborne bacteria in your home can be a powerful tool in your arsenal against indoor air pollution.

But with so many different options available, how do you know which purifier is best?

In this guide, we’ll cover air purifier basics, including how they work, what types of pollutants they address, how often you’ll need to change filters and the most important features to consider. To make sure you cover every base as you start your air purifier shopping journey, we’ll even tackle how to find the best deal on an air purifier, and send you off with a complete air purifier buying checklist.

Air Purifier

How Do Air Purifiers Work?

To put it simply, air purifiers function by capturing—or in some cases, destroying—airborne pollutants, then recirculating cleaner air. Before we dive into exactly how different types of air purifiers do this, it’s important to understand a little bit about the pollutants themselves. 

There are two types of pollutants that can negatively impact indoor air quality: Particulate matter and gaseous pollutants.

Particulate matter includes dust, smoke, pollen, pet dander, tobacco smoke, particles generated from ovens, and particles associated with tiny organisms like dust mites, molds, bacteria and viruses.

Gaseous pollutants are the result of chemical reactions between oxygen and another substance, which give off heat. Sources include gas cooking stoves, vehicle exhaust, tobacco smoke, building materials, furnishings and products like adhesives, paints, varnishes, cleaning products and pesticides.

Removing Particulate Matter

Mechanical air filters and electronic air cleaners are the two primary types of purifiers that capture particles.

Mechanical air filters consist of a fan and a filter (or multiple filters) made of a web of very fine fibers. The fan draws in air from the room, and pushes it through the filter. As the air passes through the filter, the contaminants that are suspended in the air get trapped in the web of fibers, leaving the air much cleaner. The fan then recirculates the cleaner air throughout the living space. High efficiency particulate air (HEPA) filters are a popular and effective type of mechanical filter.

Electronic air cleaners also capture particulate matter, but the mechanism is a bit different. Electrostatic precipitators, one of the most common types of electronic air cleaners, use a process called electrostatic attraction to give airborne particles an electrical charge. They then capture the particles on a series of flat plates called a collector that bears an opposite charge.

A word of caution: Some of these purifiers emit ozone, a dangerous pollutant that can be detrimental to your health. We recommend avoiding any purifiers that emit ozone—whether it’s directly or as a byproduct of their purifying process.

Removing Gasses & Odors

Gas-phase air filters use a material called a sorbent to adsorb, or collect, gaseous pollutants and odors as air passes through them. Activated carbon is a popular sorbent choice.

Gas-phase filters are generally designed to capture a few specific pollutants, so they will not remove all of the gaseous contaminants in your home. Carbon monoxide, for example, is a very dangerous gas that research suggests tends to escape at-home gas-phase filtration units.

Do Air Purifiers Work?

The most effective approach to improving indoor air quality is to identify and remove the source of pollutants. Ventilating the space with clean, outdoor air is also highly effective. Air purifiers are not as effective as either of these approaches, but are a good alternative if they aren’t possible.

While research indicates that air purifiers can’t single-handedly eliminate all contaminants from indoor air, they can help reduce them—some more than others. Here’s what we know (and don’t know) about air purifiers:

What Does An Air Purifier Do Well?

There is very little research on air purifiers as a group. But there is one area that has been heavily studied: Mechanical filtration. Several studies have established that purifiers using a mechanical filter called a High-Efficiency Air Particulate (HEPA) filter can be especially effective at removing particulate matter from the air—using these filters results in reductions of 50 percent or higher in particulate matter. And in one study of nearly 130 homes, filtration resulted in an approximately 30 percent reduction in coarse particles like dust.

Any air cleaner with a mechanical filter that has a HEPA designation has been tested and approved by the nonprofit Institute of Environmental Sciences and Technology. To receive a true HEPA designation, a filter must clear out at least 99.7 percent of particulates that are 0.3 microns or larger in size (for reference, a micron is about one twenty-five thousandth of an inch, if you can wrap your brain around that)—in a lab setting. This means that a purifier with a HEPA filter will be effective at removing particulate matter within that size range, like dust, pollen and pet dander.

Though the research on air purifiers as a category is limited, many individual manufacturers have had third party studies conducted to establish their product’s efficacy in removing specific particles or gasses. For example, in a standardized test room, AirDoctor removed 99.99 percent of a range of bacteria and viruses. Keep in mind, though, that results in a clinical setting tend to skew slightly more positive than those in a real world setting since clinical conditions are more controlled.

But What Does That Mean for Health?

There have been very few long-term studies on the impact of air purifiers on health. And linking air purifiers to specific health benefits is a bit reckless considering that in existing research, the benefits reported have been inconsistent across study participants and often, other variables were at play. For example, some participants reported regularly using a vacuum while others reported removing pets from the bedroom—both of which can skew results.

Still, there are some encouraging findings:

  • Several studies have established a correlation between indoor HEPA filters and improved lung function and respiratory health in asthma sufferers.
  • Recent, albeit small, studies have suggested that air purifiers may help improve blood pressure and heart rate.
  • Nearly a dozen studies exploring the impact of air purifiers on cardiovascular function demonstrated improved cardiovascular health among participants. 
  • A review of eight studies by the EPA focusing on the impact of air purifiers on allergy and asthma symptoms revealed modest improvements in at least one health area, such as some allergy symptoms.
  • In a recent study, asthmatic participants reported a 20 percent reduction in clinic visits after using an air purifier.

What Don’t Air Purifiers Do?

While air purifiers can be a powerful tool in your home cleaning arsenal, they have their limitations. For example, air purifiers can only capture pollutants while they’re floating in the air. So larger, heavier contaminants (like some allergens, mites, mold and pollen particles) that sink to the ground quickly often escape filtration. 

And there’s no single mechanism that captures every size and type of airborne pollutant. For example,

mechanical filters like HEPA are highly effective at capturing pollen and dust particles, but on their own don’t clear gasses or odors. On the flip side, purifiers that utilize a sorbent like activated carbon tend to capture gasses but not particles. That’s why choosing a purifier that contains both a HEPA filter and an activated carbon filter is a more comprehensive strategy.

Another limitation? Most home air purifiers are designed to filter the air in a single room, not the entire house. So if you sleep upstairs but spend most of the day downstairs, you may not reap the full benefits of the purifier—unless you invest in two.

What We Don’t Know

With research on air purifiers so limited, there are a lot of blind spots. For instance, we don’t know how effectively air purifiers remove gaseous pollutants as a group. That means we don’t know how well they stand up against radon, one of the more dangerous gasses. According to the EPA, studies on this topic are inconclusive.

What Are Air Purifiers Good For?

Now that we’ve covered the buying basics, let’s address the top two questions customers ask regarding the impact of air purifiers on specific health concerns.

Do Air Purifiers Help with COVID?

The research on the protection air purifiers can provide against the COVID-19 virus is still evolving. Here’s what the experts are saying right now:

Environmental Protection Agency (EPA)

According to the EPA, air cleaning or filtration systems by themselves are not enough to protect you from COVID-19. Still, the agency says that when used along with other best practices recommended by the Centers for Disease Control and Prevention (CDC) and other public health agencies (think social distancing and mask-wearing), filtration can be part of a comprehensive plan to reduce the possibility of indoor transmission.

To maximize its air cleaning potential, the EPA recommends placing your purifier in the room in which you spend the most time. Directing the airflow so it does not blow directly from one person to another, they say, will help reduce the risk of airborne transmission, so be strategic in your placement of your air purifier.

The Mayo Clinic

This organization says that since COVID-19 is not expelled on its own, it has to attach to something else to travel, like mucus, a respiratory droplet or a piece of dust in the environment. They state that while a HEPA filter does not kill the COVID-19 virus, those elements that can transport the virus can attach to a filter, which means they won’t continue to circulate in your living space. They caution that purifiers with HEPA filters only work when they are running, so you may need to keep the fan in your unit running continuously for them to be effective. They also emphasize the importance of cleaning and replacing the filters regularly to ensure maximum efficiency. 

Centers for Disease Control and Prevention (CDC)

In an exciting new study out of the CDC, the use of a portable air cleaner significantly reduced aerosol exposure to SARS-CoV-2 (the virus that causes COVID-19) in a meeting scenario.

In this study, the use of HEPA air cleaners in a conference room significantly reduced the exposure of a presenter and nearby attendees to airborne particles produced by a simulated infected participant. 

The study compared the efficacy of air cleaners alone, masks alone, and both air cleaners and masks, and found the following:

  • The use of HEPA air cleaners alone reduced respiratory aerosol exposure by up to 65 percent 
  • The use of masks alone reduced exposure by up to 72 percent
  • The use of both air cleaners and masks reduced exposure by up to 90 percent

These findings support the usage of portable HEPA air cleaners and mask-wearing as strategies for reducing exposure to indoor aerosols containing SARS-CoV-2, which could help limit transmission of the virus and decrease incidences of COVID-19 illness and death.

Note: The air cleaners were most effective when they were located in the center of the room close to the aerosol source.

Do Air Purifiers Help with Allergies?

Allergens are substances that can create immune responses in the form of irritating allergies or asthma. Common airborne allergens include dust mites, pollen and pet dander. Air purifiers can help reduce the number of these allergens, but certain conditions must be met for them to be effective:

1. The particles must be suspended in the air long enough for the purifier to capture them.
2. The purifier must be powerful enough to move most of the air in the room through the filter.
3. The purifier must contain a filter or other mechanism capable of removing the particulate matter from the air passing through it.

Particulate matter is measured in microns. For reference, the average human hair is about 70 micrometers in diameter; a granule of fine beach sand is about 90 microns. Since most common allergens take the form of extremely fine particles—pollen grains are about 30 microns, dust mite waste particles are about 20 microns, and cat allergen particles vary from about one to 20 microns in size—your best bet is an air purifier that contains a true HEPA filter, which can remove very fine particles from the air. The industry standard for a true HEPA filter requires that the unit must be able to remove at least 99.97 percent of particulates measuring 0.3 micron in diameter in a lab setting. And multiple studies of room air purifiers have demonstrated that using HEPA filters results in reductions of 50 percent or higher in particulate matter.

Keep in mind that HEPA filters in a real world, home setting may not be quite as effective as in a laboratory, since new pollutants are constantly emerging. Also important to keep in mind: There is no industry standard for the terms “HEPA-like” or “HEPA-type.” Stick with a filter that has a true HEPA designation for best results.

Here’s a little more detail on the impact of air purifiers on specific allergens:

Dust Mites

Dust mites are microscopic, insect-like pests that feed off of the dead skin cells found in the dust in your home. Their secretions and fecal matter can trigger allergic reactions and asthma in many people. In fact, dust mites are one of the major indoor triggers for people with allergies and asthma.

And dust mites are everywhere. They’re in your furniture, carpets and curtains, even your bed—research suggests that nearly four out of five homes in the U.S. have detectable levels of dust mite allergen in at least one bed. 

To reduce the presence of dust mites, make sure you’re dusting regularly, minimize humidity in your home, wash your sheets and pillow cases in warm water once a week, and consider doing away with carpets, drapes and curtains. 

An air purifier can also help in the battle against dust mites, provided it contains a HEPA filter, which is capable of filtering dust particles. In one 2018 study of about 130 households, HEPA filtration resulted in a roughly 30 percent reduction in coarse particles, like dust. 


In high enough concentrations, indoor mold particles can be dangerous for those with asthma and other lung conditions, and can be particularly irritating for allergy sufferers. Reducing the humidity in your home can be a very effective strategy for minimizing mold growth, as can using an air purifier with a HEPA filter.

Just opt for a HEPA filter made of fiberglass or other synthetic material since the mold that produces allergenic spores grows on cellulose, and many of the less expensive filters are made of this material.

Pet Dander

Just like humans, dogs and cats are constantly shedding skin cells (and fur). While this is a completely normal process, it can be problematic for those who are sensitive to these substances. Luckily, most air purifiers with a HEPA filter are well equipped to remove pet dander particles from the air. 

A Beginner’s Guide to Air Purifier Types

There are several different technologies air purifiers employ in order to reduce airborne pollutants. Some capture particulate matter, others capture gasses. Some trap contaminants, others destroy them. Some tackle large particles, others get more microscopic. Here’s a look at some of the common types of air purifier technology and how they work:

Air Purifiers with Mechanical Filters

Mechanical filters use fans to force air through a web of very fine fibers, which trap particles as they pass through.

Most experts agree that the most effective purifiers contain a High-Efficiency Air Particulate (HEPA) filter, a type of mechanical filter that contains mesh or extremely fine fiberglass threads (we’re talking thinner than a strand of human hair), designed to collect airborne particles of different sizes. These filters contain a fan that draws air in, so the particles suspended in the air can then be captured in the filter. One of the appeals of a HEPA filter is that it can capture pollutants of various sizes, including ultra-fine particles like dust, dander, pollen, mold and many other common allergens.

Any air cleaner that has a HEPA filter has been tested and approved by the nonprofit Institute of Environmental Sciences and Technology. HEPA filters are designed to clear out at least 99.7 percent of particulates that are 0.3 microns or larger in size (for reference, a micron is about one twenty-five thousandth of an inch, if you can wrap your brain around that). And, multiple studies show that using purifiers with HEPA filters results in particulate matter reductions of 50 percent or higher. Keep in mind that the efficacy of these purifiers in home settings is likely much less since new pollutants are constantly emerging.

Also important to keep in mind: True HEPA filters are among the most effective options and are therefore the most recommended by experts. However, filters that are labeled “HEPA-type” or “HEPA-like,” have not been certified to meet the requirements of a true HEPA filter, which means they may not be as effective.

Here are some of the pros and cons of a true HEPA-based air purifier:

Designed to clear out at least 99.7 percent of particulates that are 0.3 microns or larger in size. This includes dust mites, pet dander, pollen and some mold spores. Cannot remove VOCs, viruses, bacteria and small particulates under 0.3 microns (but pairing it with an activated carbon filter designed to address these is a good resolution for this).
May be especially beneficial for those with allergies or asthma. Filters need replacing about every six to 12 months, which can get expensive—they can cost anywhere from $20 to $200 per filter, with most falling in the $75 to $150 range.
Any purifier that has a true HEPA filter has been tested and approved by the nonprofit Institute of Environmental Sciences and Technology.

Air Purifiers with Activated Carbon Filters [H3]

These types of purifiers use activated carbon, a material composed of granules of coal, wood, coconut shells, nutshells or other carbon-rich substances to filter harmful chemicals from the air. As air flows through the activated carbon, the contaminants stick to the surface—a process called adsorption, leaving the air cleaner.

According to the EPA, purifiers that use activated carbon filters have the greatest potential to remove gasses and VOCs from the air. Since mechanical filters (like HEPA filters) are designed to capture particulate matter and not gasses, most experts recommend getting an air purifier that includes both a HEPA and an activated carbon filter for the most effective and comprehensive purification system.

It is important to note that while activated carbon filters are designed to trap odors and small, gaseous compounds, they’re not particularly effective against formaldehyde, ammonia or nitrogen oxide.

Another important consideration: Once all the available surfaces of the activated carbon filter are covered with contaminants, the filter will need to be replaced in order for the unit to continue to be effective. How often this needs to occur depends upon the concentration of contaminants in the air and the size of the collection surface, but typically, home air purifiers of this kind will need the filters replaced every three to six months.

Designed to trap small, gaseous compounds, volatile organic compounds (VOCs), odors and more. Not effective against formaldehyde, ammonia or nitrogen oxide.
Can be paired with a HEPA filter to capture both gasses and particulate matter like pollen, dust, pet dander and more. Typically only last three to six months before they stop working at peak performance.

Ozone Generators

These purifiers function by deliberately producing the molecule ozone, which then reacts with certain pollutants to alter their chemical composition.

We do not recommend ozone generators for two reasons: 

  1. They can be harmful
    Studies show that ozone may cause decreases in lung function and increased risks of throat irritation, coughing, chest pain and even lung tissue inflammation. According to the EPA, ozone may also exacerbate asthma, emphysema and bronchitis.

    The EPA reports, under certain use conditions, ozone generating air cleaners can actually produce levels of ozone that are significantly higher than those thought to be harmful to human health.
  2. They aren’t especially effective
    EPA-reviewed studies have demonstrated that low levels of ozone don’t effectively eliminate indoor pollutants. In fact, the levels of ozone that are required to be effective are well above the amounts deemed detrimental.

For these reasons, we advise against purchasing these types of air purifiers—as do organizations like the EPA. This is also why we have not included a pros and cons list for these products—we feel that the cons far outweigh the pros.

Electronic Air Purifiers

Electronic purification systems include ionizers and electrostatic precipitators, which function by giving air particles an electrical charge, then attracting these particles back to a collector plate with an opposite charge, or inside the unit itself.

While these devices may remove small particles from indoor air—like those from tobacco smoke, they do not remove gasses and odors, and may not remove larger particles like pollen and house dust allergens.

A word of caution on ionizers and electrostatic purifiers: According to the EPA, the technology used in these types of air purifiers can indirectly produce ozone, a pollutant that can cause lung irritation—particularly in those who already have asthma or respiratory conditions.

Thus, we do not recommend these types of units unless they do not emit ozone. 

Other Air Purifier Types

Other air purifier technologies exist, although the research on their safety and effectiveness is even more limited than the more common types listed above.

Here are two of them:

Ultraviolet Germicidal Irradiation (UVGI) Air Purifiers: These function by exposing contaminants to UV light. But since some bacteria and mold spores are resistant to UV radiation, the light must be powerful enough and the exposure must be long enough to be effective.

Photocatalytic oxidation (PCO) Air Purifiers: These use UV radiation and a photocatalyst, such as titanium dioxide, to produce radicals that chemically alter gaseous pollutants. However, depending on the pollutant, this reaction can sometimes generate harmful byproducts, including ozone, formaldehyde, nitrogen dioxide and carbon monoxide. Their efficacy has not been established, and one clinical study conducted by researchers at Syracuse University in New York reported that the devices did not effectively remove any of the volatile organic compounds (VOCs) typically found in indoor air. 

For our full list of the best air purifiers, click here >

Air Purifier Shopping Considerations

Aside from the model, there are additional factors to consider when shopping for an air purifier. Here are a few of them:


There are a few certifications and labels you’ll want to keep an eye out for as you start your search for the best home air purifier for you.

Association of Home Appliance Manufacturers (AHAM) Seal

When shopping for an air purifier, you’ll notice that many have an AHAM Verifide seal. This seal indicates that the purifier has voluntarily gone through standardized testing in a laboratory by the Association of Home Appliance Manufacturers (AHAM). Based on this testing, AHAM certifies the air purifier for its ability to remove three common types of air pollutants—smoke, pollen and dust.

AHAM’s standards are designed to ensure the safety and efficacy of several home care appliances, including air purifiers. The certification program is voluntary, so if an air purifier has the seal, it can be a good indication that the brand truly stands behind the product.

Clean Air Delivery Rate (CADR)

AHAM’s voluntary certification program provides something called a Clean Air Delivery Rate (CADR), which indicates how effectively the air purifier removes tobacco smoke, dust and pollen from a room. More specifically, the CADR signifies the volume of clean air a purifier produces when on its highest speed setting—in cubic feet per minute. So the higher the CADR, the more efficient the air purifier. HEPA filters tend to have among the highest CADRs of all air purifier types.

Something to keep in mind: There are different CADRs for each of the three pollutants tested—tobacco smoke, dust and pollen. So, if you are concerned about one of these in particular, you’ll want to compare the CADR for that contaminant across different air purifiers.

Energy Star Label

You also may notice that many air purifiers have an Energy Star label. This label indicates that the purifier meets rigid energy efficiency guidelines established by the EPA.

While this certification is not an indication of a purifier’s effectiveness, it can be an important consideration when comparing costs of different air purifiers. Most air purifiers should be kept running around-the-clock to be effective. Since the longer they run, the more energy they’ll use, investing in an air purifier can mean increasing your energy bill. Generally speaking, Energy Star certified purifiers are 40 percent more energy-efficient than standard models.

Room Size

While some air purifiers are designed for small, single rooms, others were created to purify much larger spaces. It’s important to consider the area you want your purifier to cover to ensure maximum performance and to keep the price point down—a larger coverage area often comes with a higher price tag.

The CADR referenced above isn’t just useful for determining an air purifier’s effectiveness at removing specific pollutants, it can also help you determine how large a space the purifier was made for. The higher the CADR, the more particles the air cleaner will remove and the larger the area it can serve. Again, it’s important to keep in mind that the CADR is typically measured at the air cleaner’s highest speed—which usually is the loudest setting.

The EPA provides the following estimations of the minimum CADR required for various room sizes:

Room Area (square feet) Minimum CADR
100 65
200 130
300 195
400 160
500 325
600 390

Note: CADRs are calculated based on an eight foot ceiling; if you have higher ceilings, you may want to consider a purifier with a higher CADR.

Noise Level

An air purifier’s noise level is measured in decibels (dB(A)). For reference, a noise level of 40 decibels is roughly equivalent to the level of noise generated by your refrigerator; a dishwasher is around 70, according to the Centers for Disease Control and Prevention (CDC). Note: If an air purifier is marked as 70dB(A), it’s 10 times louder than a 60dB(A) air purifier.

When you’re comparing noise levels between units, make sure to consider if the level refers to the lowest or highest fan setting, and which setting you’ll likely use most often.

If noise level is a concern for you, there are a few things you can do. Since the higher the setting, the louder the purifier is likely to be, you can purchase a purifier intended for a larger room so you can run it on low and still get the filtration you’re after. Or, you can run your purifier on the higher settings when you’re not within earshot, and run it on low when you’re in the room.

Replacement Filters

There are many factors that impact how often an air purifier filter needs to be replaced—like how polluted the space is and whether you keep it running constantly. Each air purifier manufacturer has its own recommendations but generally speaking, you’ll need to replace pleated or mechanical filters every six to 12 months and activated carbon filters every three months.

The price of filters varies greatly, ranging from as little as $20 each to more than $200. One way to save yourself money on filters is to look for washable, reusable options. Or, sign up for a filter subscription service when you purchase your air purifier—many manufacturers offer discounts for those who sign up for an auto-delivery filter program.

It’s also wise to consider purchasing a purifier that includes filter service indicator technology. This functionality serves to notify you when a filter is in need of replacement, which can save you from prematurely replacing your filters or worse, using the same filters so long they stop being effective.

Ease of Use

If you’d like to use your air purifier in multiple rooms or locations, you’ll want to ensure you’re able to move it around easily. Choosing an air purifier that isn’t too heavy and has handles or wheels is a good way to ensure that you’ll be able to transport it from room to room.

If convenience is a priority, you might also want to consider investing in an air purifier that comes with a remote control or that functions through an app on your phone—so you can turn it on and adjust the settings when the purifier is out of reach.

Another feature that ups the convenience factor? An automatic air quality sensor. This technology detects how polluted the air is and automatically adjusts the cleaning setting for you.

Your Budget

Of course, you’ll want to consider how much you’re to spend when shopping for air purifiers, which can range in price from $200 all the way up to $2000 or more.

When you’re doing the math, don’t forget to factor in replacement filters for any purifier that relies on them to function. The frequency with which you’ll need to replace your filters depends on how often you run the purifier (most manufacturers suggest keeping them running around the clock for maximum efficiency), as well as how polluted the space they’re purifying. It’s safe to assume you’ll need to replace most filters at the very minimum, once or twice per year—but likely more often than that. Filters can range from $20 to more than $200, depending upon the type.

Since activated carbon filters become saturated faster than pleated mechanical filters, if you opt for an air purifier that uses this filter type, be prepared to replace them more often—about every three months. Activated carbon filters cost up to $50 each. 

And don’t forget that most purifiers need to be left running continuously to be effective. This could mean an increase in your energy bill.

Features to Avoid

While the research on air purifiers is ever-evolving, there’s one thing that most experts agree on: It’s best to avoid units that emit ozone.

As their name implies, ozone generators deliberately produce ozone. Ion generators and some other electronic air cleaners also emit ozone as a result of their filtration process.

This is dangerous because inhaling ozone can damage the lungs. Even in relatively low amounts, ozone can cause chest pain, coughing, shortness of breath and throat irritation, can worsen asthma, and can compromise the body’s ability to fight respiratory infections. Ozone is so dangerous that several government agencies have established standards to limit human exposure. And studies suggest that to be effective at eliminating pollutants from indoor air, the concentration of ozone would have to greatly exceed these standards.

Thus, it’s in your best interest to avoid purchasing an air purifier that emits ozone.

Where to Buy Air Purifiers?

If you know you want to purchase an air purifier, but you’re not sure where to do it, you have options:

Buying Your Air Purifier In-Store

Home air purifiers can be found in many retail locations, including Best Buy, Walmart and Target. The benefits of purchasing your purifier in a store are that you get a sense of the size of the unit, making returns and exchanges is typically a seamless process, and you can take advantage of store coupons or promotions. 

Buying Your Air Purifier Online

Air purifiers can also be conveniently purchased online—either from eComm sites like Amazon, or directly from the manufacturers. Purchasing from the actual brand is often the best approach since you can take advantage of special promotions, and you’re guaranteed a direct line of communication to the manufacturer’s customer service team. Plus, most manufacturers offer money back guarantees and shipping discounts.

How Much Are Air Purifiers?

Air purifiers range in price from around $200 to as much as $2000, depending on their filtering capabilities and the size of the room they cover.

You’ll also need to factor in the cost of replacement filters, especially if you buy an air purifier model with multiple filters—you’ll need to replace these at least once or twice per year, but likely more often than that. These can range from $20 to more than $200.

When is the Best Time to Buy an Air Purifier?

While many air purifier brands offer promotions throughout the year, you can almost count on getting the deepest discounts during holidays. Cyber Week, which generally begins around Black Friday and continues through Cyber Monday, tends to also be a popular time for price reductions on air purifiers.

What Are the Top Air Purifier Brands?

Air purifiers have grown in popularity over the past decade, which means there’s no shortage of manufacturers claiming to be the best. We conducted side-by-side comparisons of some of the top rated air purifier brands, and determined AirDoctor, NuWave and Molekule to have some of the best products on the market. You can check out how they stack up here.

Let’s Do This: Your Air Purifier Buying Checklist

By now, you’ve probably determined whether you’re ready to invest in an air purifier, and hopefully we’ve helped you narrow down the type of air purifier you want—and some of the must-have features.

So if it’s time to start shopping, use this handy checklist to ensure you’ve covered all the bases.

  • What type of mattress is it?
  • What type of pollutants does it address?
  • Does it have any certifications and does it have an Energy Star label?
  • What is the size of the room I need it to cover?
  • What is the noise level?
  • What filters does it use and how often do they need to be replaced?
  • How easy is it to use?
  • Does it fit my budget?

And with that, you’re off! We hope this guide has given you the information you need to seek out your best night’s sleep and purchase with confidence. Happy air purifier shopping!

Other Ways to Clean Indoor Air

One of the most effective ways to improve the quality of indoor air is to eliminate—or at least control—the source. For example, minimizing use of a fireplace and requesting that smokers go outside are more effective strategies to reduce indoor smoke pollutants than relying on an air purifier. 

Often, indoor air quality is compromised simply due to poor ventilation. If allergies aren’t a concern, keeping the windows open is a great way to increase the room air change rates. Using fans is also a great strategy—position one fan to “push” indoor air out one window, and another fan to draw fresh outdoor air inside from a different window.

If allergies are a concern, investing in an HVAC system may be beneficial—just set the fan to run continuously, even if it isn’t cooling or heating the air. 

You should also use an exhaust fan while cooking, and strive to reduce the use of chemicals in your home when possible.