Investing in one of the best air purifiers can help you to breathe easier in the knowledge that the air you and your family are inhaling is as squeaky clean as it can get. Clean indoor air is of concern to many people, particularly those who have respiratory conditions or young children.
The sheer number of air purifier options available can feel overwhelming, so we’ve narrowed it down to the options that performed best under our rigorous testing protocols. We test the best air purifiers in our designated testing facility, as well as real-world settings, to ensure this round-up of the products really are at the top of their game.
If you’re not sure whether or not you need an air purifier, you can skip ahead to our FAQ section at the bottom of this guide, to read through advice from doctors and the Environmental Protection Agency on the benefits of air purifiers and how they can help keep your indoor air clean.
If you’re looking specifically for an air purifier for allergies, we’ve put together a separate guide with your needs in mind. Read on for the best all rounders
Best air purifier overall
Reasons to buy
Reasons to avoid
The Levoit 400S performed best to remove airborne particles in our at-home testing, capturing at least 99.5% and up to 99.9% of particles down to 0.3 microns in size during testing.
Its sleek and stylish cylinder shape with a neutral colorway makes it an easy addition to any room, whatever the décor, while a color-coded display gives users a great visual on air quality at any given moment.
The Levoit 400S scores an impressive 5 stars out of 5 on Amazon, with 85% of reviews giving it the full 5 stars. Negative reviews cite problems with the VeSync app and a lack of sturdiness in design. Positive reviews praise the purifier’s accuracy in tracking 2.5 microns and its ability to manage and remove unpleasant odors, dust and pet dander. Customers particularly like the look of the Levoit 400S, although some say it feels a little big. They also appreciate how quietly the purifier runs on its lower settings.
The air purifier is light and features indented handles at either side, which we found made it easy to move it from room to room.
A companion app that users can download gives useful data on air quality and allows users to schedule and time the air purifier to fit round a busy family schedule. Unfortunately, for all its great functionality, the VeSync app wasn’t always reliable for us. During the course of our testing, we had to uninstall and reinstall the app twice when it crashed.
The quietest setting on the Levoit 400S is barely discernible, while the most powerful setting still clocks in at just 52 decibels.
Stylish, quietly powerful, and with an intuitive, easy-to-use Smart interface, the Levoit 400S is our top pick of air purifiers. It could be the ideal appliance for you if you’re looking for an effective air purifier that’s big on performance but doesn’t blow the budget.
- Read our full Levoit 400S review
Best budget air purifier
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Small enough for any desktop or shelf, the Levoit H132’s compact size and low price makes it the ideal air purifier for someone looking to try their first air purifier at home. If you have a small apartment, or you simply want to use an air purifier in one room only, then this might be the product for you.
The Levoit H132 scores an impressive 4.7 out of five stars on Home Depot. Negative reviews are few and far between, with one customer finding problems with the motor whining after a few weeks. Most reviews are positive, with users praising the purifier as convenient and highly efficient at reducing the symptoms of allergies. Customers particularly like how quiet the purifier runs, even at the highest setting. Users say the purifier worked so well to improve indoor air quality that they bought a second one for another room.
The Levoit H132 might lack the wow–factor of more stylish purifiers. However, what it lacks in style, it certainly delivers in sheer affordability. Available for under $100, this is definitely one of the best air purifiers for those on a budget.
While this particular air purifier might lack the HEPA filter that gives premium air purifiers their mark of quality, it does come with an in-built dimmable nightlight, making it an ideal air purifier for a nursery or child’s bedroom. While it’s not possible to pre-program the unit, a memory function means that previous fan settings are logged before it powers down.
Unfortunately, the Levoit H132 didn’t quite live up to expectations when it came to testing how well it absorbed particles, consistently falling some way below the 99.97% expected from a device with an H13 HEPA filter. However, running the purifier for longer periods may yield better results.
The Levoit H132 may not have all the bells and whistles of a smart air purifier, but its affordability and compact size makes it the ideal entry-level indoor air purifier that performs well in small to medium-sized rooms.
- Read our full Levoit H132 review
Best air purifier for cooling
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Reasons to avoid
The Dyson Purifier Cool is one of the most stylish air purifiers on the market. Its unusual design marks it out as a talking point in any room, while simple but genius extras, such as a magnetic remote control, take it a step up from your average air purifier.
The Dyson Purifier Cool scores an average of 4.2 out of five stars on Home Depot. Negative reviews cite problems with the sensors’ baseline readings, poor fan quality, and noisiness when in use. Positive reviews praise the purifier’s ability to improve the symptoms of allergy sufferers, as well as removing unpleasant odors. Customers particularly like the integration with smart devices, the auto setting and the purifier’s stylish design, with one user commenting, ‘It looks like a piece of art’.
The purifier also doubles up as a fan in hotter weather, although this isn’t as powerful as some users would like. Users can activate, schedule and monitor their purifier via the Dyson app, allowing them to set fan speed, timers and check air quality whether they’re home or away.
A clever LCD display flicks between icons that show air quality data in real time, while an auto-mode senses air particles and adjusts fan settings to suit.
We burned a series of matches to test how well the purifier captures particles. At a level 6 setting, we found that the purifier removed 98% of particles smaller than 0.3 microns, 72% of particles smaller than 2.5 microns and 73% of particles measuring smaller than 10 microns. At a level 10 setting, we found that the purifier captured 95% of particles smaller than 0.3 microns, 96% of particles smaller than 2.5 microns, and almost 100% of particles measuring smaller than 10 microns.
Based on these limited tests, our results weren’t consistent enough to support Dyson’s claim that it can remove 99.95% of particles. However, it still performed well, often capturing more than 95% of monitored particles when used at its highest setting for at least 30 minutes.
The Dyson Purifier Cool’s high price tag may be too expensive to suit everyone’s budget, but its stylish, sleek design and smart, connected functionality is impressive.
- Read our full Dyson Purifier Cool review
Best air purifier for large spaces
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Reasons to avoid
The Blue Pure 221 is designed to cover areas of up to 600 square feet, making it an excellent choice for homes with larger rooms or office spaces. With three power settings operated with a one-touch button, simplicity is the key for this purifier.
The Blue Pure 221 scores an impressive 4.8 out of five stars on Home Depot, with hundreds of five-star reviews from satisfied customers. Positive reviews praise the purifier’s performance, saying it helps them sleep better, feel less congested, and enjoy cleaner air quality in their home. Many users love the unit’s design and are happy with how quiet it can run. Negative reviews cite problems with performance, the expense of replacing filters, and some complain that the higher settings are too noisy.
Our at-home tests found the Blue Pure 221 to be consistently better than all the other air purifiers we tested. Despite its lack of Smart technology, it out-performed purifiers at almost double the price.
We burned a series of matches to test how well the purifier absorbed particles. At a level 2 setting, we found that the purifier absorbed 99.7% of particles smaller than 0.3 microns, 99.5% of particles smaller than 2.5 microns, and 100% of particles measuring smaller than 10 microns. At a level 3 setting, we found that the purifier absorbed 99.9% of particles smaller than 0.3 microns, 99.6% of particles smaller than 2.5 microns, and 100% of particles measuring smaller than 10 microns
Some users may be put off by the unit’s weight and bulk. But it’s still a stylish machine that’s thoughtfully designed. Plus, its customizable fabric pre–filters make it easy to pair the unit with any home’s color scheme.
Our verdict? A dependable workhorse of an air purifier that puts performance above presentation. Plus, we like the fact that it’s energy star certified and cheap to run.
- Read our full Blue Pure 221 review
Best air purifier with eco mode
Reasons to buy
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The Coway AP 1512 is known as a standout air purifier due to its excellent value and high-quality performance. It may not be as stylish as other air purifiers in our round-up, but our testing found it to do a remarkable job of removing particles in just 30 minutes.
The Coway AP 1512 HH Air Purifier has an impressive 4.7 star rating out of five on Amazon, and with reviewers praising its quiet running, affordable replacement filters and its economical performance, it’s fair to say that this is a total winner with users. Negative reviews said that the included instructions did not quite go far enough in instructing users how to set up and use their air purifier. Positive reviews were sold by how lightweight and easy to maneuver the air purifier was, as well as the design which was easy to integrate into their home.
For an initial cost of under $300, this air purifier can offer you a four-stage filtration system, a HEPA filter and coverage of up to 361 square feet. The air purifier itself is packaged in a neat, sleek design and available in two different colors: Black and white.
This air purifier excels when it comes to dust and eradicating odors, with a pre-filter and odorization filter for reducing contaminants in the air. It’s also inconspicuous when it comes to noise, making it a suitable addition to any bedroom when paired when its smaller size.
The Coway-AP-1512HH air Purifier also benefits from a built-in particle sensor. That means that you can get an idea of the air quality in your home from the color coding system on the top of the device. It’ll show a blue light when the air is clean, purple to flag pollution and red for high pollution. Another clever feature of the Coway AP- 1512HH is the sensors that can adjust the fan speed to keep the air clean, so that you don’t have to mess with the settings.
We particularly liked the Eco mode on the Coway AP-512HH which worked well to power down the air purifier when air pollution was low, saving energy and money. Our tester also found the auto mode worked well to toggle between fan settings depending on indoor air quality.
The Coway AP-1512HH is an air purifier suited to rooms up to 361 square feet, making it suitable for smaller spaces and bedrooms. If you need something for a larger room, then you might want to look elsewhere.
- Read our full Coway AP-1512HH review
Best air purifier for small spaces
Reasons to buy
Reasons to avoid
Light and compact, the KOIOS EPI810 is the smallest air purifier we’ve reviewed. It will sit comfortably on any office desk or shelf and its 2.5lb weight makes it light enough to take travelling.
The Koios EPI810 has an impressive 4.5 stars out of five on Amazon.com. Users who gave it the full five stars praise the purifier’s performance as well as its conveniently compact size. Others rate its ability to neutralize unpleasant cooking odors and pet smells. Many reviewers have bought several purifiers to use in multiple rooms. Negative reviews point out that the purifier can be noisy at its highest setting, or that they have been unable to switch the night light setting off. Other criticize the quality of the unit as having a ‘cheap’ feel and say the replacement filters are too expensive, at almost half the price of the base unit.
The purifier can operate from a mains socket or via USB, while a simple one-click button control makes it one of the easiest air purifiers to operate straight out of the box. A built-in night light makes it a good choice for a nursery or kids’ room.
Our at-home incense smoke test evaluated how well the purifier performed after burning five incense cones simultaneously and found mixed results. While the KOIOS EPI810 absorbed an impressive 99% of particles measuring 10 microns, it only absorbed 52% of particles smaller than 2.5 microns
While it doesn’t have the wow factor when it comes to design, or the sophistication of a smart, connected air purifier, the KOIOS EPI810 may work well if you want something easy to operate. However, a noisy higher setting and a lacklustre performance in our at-home tests may put some users off.
- Read our full KOIOS EP1810 review
Our favorite tower air purifier
Reasons to buy
Reasons to avoid
Despite its basic settings, the HoMedics TotalClean Deluxe 5-in-1 is a good value air purifier that’s efficient, easy to set up and intuitive to use — all while taking up little space within your home or office.
The HoMedics TotalClean Deluxe 5-in-1 scores a really good rating of 4.6 stars out of 5 on Amazon, with 79% of reviews awarding it the full 5 stars. Positive reviews tend to praise this air purifier for its effectiveness, energy efficiency, portability and relatively low noise levels. Many users also appreciate the 3-year warranty and like that the lights on the HoMedics TotalClean Deluxe 5-in-1 are not too distracting during the night.
HoMedics TotalClean Deluxe 5-in-1 is a tower air purifier equipped with UV-C technology and a 360-degree true HEPA filter. According to the manufacturer’s claims, this piece of equipment can remove up to 99.9% of harmful microbes, mold, fungi and airborne allergens. And thanks to its pre-filter and additional carbon filter, it can also be effective at getting rid of lingering odors, pet hair and volatile organic compounds — all for less than $250 per unit.
The HoMedics TotalClean Deluxe 5-in-1 air purifier was clearly designed to perform, no matter the circumstances. This piece of equipment comes with UV-C technology and an ionizer, which, according to the manufacturer claims, can effectively kill most bacteria, viruses, molds and fungi. It also contains several different filters to ensure no unwanted pollutants are left hanging in the air.
In our tests, the HoMedics TotalClean Deluxe 5-in-1 demonstrated really good performance in several different circumstances, particularly in relation to small and medium-sized particles. In fact, in our match smoke test it removed 88.5% of 0.3 nano particles on the highest setting after just 30 minutes.
- Read our full HoMedics TotalClean Deluxe 5-in-1 Review
Best for homes with pets
Reasons to buy
Reasons to avoid
The Levoit Vital 200s offers four fan speeds, three separate modes including pet, auto and sleep mode, and a connected app that allows you to control your air purifier remotely, wherever you are. It also works with Google Assistant and Alexa voice control devices.
Users appear to be raving about their Levoit Vital 200s air purifiers. BestBuy users award it a five-star rating, with one BestBuy customer remarking, “We have seen a great difference in our home. With four cats, dust and a teenager, it really took care of odors, cat hair and dust. Runs quiet, quieter than I ever thought it would.”
Putting the Vital 200s through its paces in our at-home testing, we found it impressive and efficient at removing particles measuring as small as 0.3 microns. Pet dander, mold, dust and smoke were absorbed while chemicals and odors from everyday household cleaning and cooking were neutralized by the three-stage filtration system. This includes a washable pre-filter, an H13 True HEPA filter and a high-efficiency activated carbon filter.
The Vesync app is easy to use and allows users to track their real-time air quality data and historical data, revealing peaks in poor air quality over the day and taking the guesswork out of what’s causing bad air quality in your home.
While the large boxy design may not be suited to users who want a sleek and stylish air purifier, or those with small rooms, the no-frills aesthetic makes the Levoir Vital 200s the perfect choice for most users. While it’s not cheap, it is relatively affordable, and if you value clean indoor air quality, you won’t be disappointed with its performance.
- Read our full Levoit Vital 200s review.
Best aesthetic design
Reasons to buy
Reasons to avoid
The Sensibo Pure air purifier boasts a sleek and modern design with a compact size that fits well on tabletops or shelves.
The user-friendly interface includes touch-sensitive controls on the top panel, seamlessly integrated into the design. An LED strip provides real-time feedback on air quality, with different colors indicating the air quality level, allowing for easy monitoring at a glance.
The Sensibo Pure seems to have garnered a decent reputation among Amazon users, earning a solid rating of 4.1 stars out of 5 on the popular e-commerce site. Many users appreciate its hassle-free setup and immediate usability. They particularly praise its ability to provide accurate information about air quality. One satisfied customer raved: “Amazing air purifier. The app is fantastic and works flawlessly. It lets you know when your air is terrible and automatically boosts the power to make the air good. Highly recommend.”
In terms of features, the Sensibo Pure offers a True HEPA filter for capturing airborne particles, suitable for spaces up to 1,000 square feet. It provides real-time air quality monitoring with insights and notifications through the Sensibo app, enabling remote control and scheduling. The purifier is energy-efficient, has a filter replacement indicator, and has a 2-year warranty.
While the device receives positive reviews, some users mention the noise level at high fan speeds and occasional difficulties with app connectivity as drawbacks.
The Sensibo Pure air purifier combines an appealing design with effective air purification features. However, potential buyers should consider the noise factor and ensure compatibility with their preferred device for app control.
- Read our full Sensibo Pure Review
Best for commercial spaces
Reasons to buy
Reasons to avoid
Due to its large size, we’d recommend the DH Lifelabs Sciaire+ HEPA Air Purifier for those with spacious homes or commercial spaces. Despite its substantial dimensions, it offers efficient air purification and ease of use, making it a suitable choice for the right environment.
Despite its size and relatively expensive cost, users rate this air purifier highly. They enjoy how easy it is to set up and start using immediately. Many love the large design and glossy screen at the top, with one user commenting, “First impressions were that this purifier looks superb - a sleek silvery tapered tower design that’s the polar opposite from an industrial box.” They also enjoy how quiet the purifier is during operation.
The purifier also features a dual air deodorization process, breaking down odors and neutralizing unpleasant smells. It covers areas up to 452 sq. ft., with Wi-Fi connectivity and app control. The design is big, though, measuring 35.4 inches in height and 13.6 inches in diameter. It may be too large for smaller homes. It performed well in our at-home user testing and was super-quiet during operation, even on auto-mode.
The Sciaire+ HEPA air purifier by DH Lifelabs utilizes 16 ion generators to bond with airborne particles actively, achieving a 99.99% elimination rate of bacteria and viruses. The 3-in-1 filter system, including pre-filter, HEPA filter, and activated carbon filter, effectively removes particles as small as 0.1 microns, addressing pet dander, pollen, dust, allergens, and volatile organic compounds (VOCs).
- Read our full DH Lifelabs Sciaire + HEPA Air Purifier review
We spoke with members of the Environmental Protection Agency to confirm the latest research and findings on air purifiers.
Dr Ross Perry qualified at Guy’s & St Thomas’ Hospital Medical School in 1994. He is now the medical director of Cosmedics Skin Clinics. For this piece, he offers advice on potential pollutants in the home and the efficacy of air purifiers.
Dr. Kara Wada is an allergist-immunologist at The Ohio State University Wexner Medical Center and a clinical assistant professor of allergy and immunology at The Ohio State University College of Medicine.
How we test
How do we test air purifiers at Live Science?
Every air purifier in this guide has been tested to the exact same standards, using the same processes. We created a series of tests to measure particles of different sizes, to see how each air purifier performs with certain types of impurities. We use a particle counter for all our testing, and our equipment is capable of measuring the smallest pollutants (0.3 microns) that can be removed from the air by a purifier.
We start by running an ambient air quality test, where we run the air purifier in multiple rooms in a home to see how it performs at the regular setting, and the highest possible setting (below 50 decibels). We make note of readings after 15 and 30 minutes to see the speed at which the machine removes particles from the air. We also measure the noise levels generated by the fan, to comment on how noticeable the purifier will be in an average home.
We then test different particle sizes using matches and incense to generate different types of smoke, taking measurements at regular intervals and on different speed settings.
Our testing also takes into account the size of the unit, the cost, ease of use, availability of additional parts, and the energy use on the lowest and highest settings. Finally, we check online user reviews to see what people think, and we test for any persistent problems or defects that we read about.
As per our testing policy, we fully disclose all our findings in our reviews.
Are air purifiers worth it?
The best air purifiers are a great way to help improve the air space around you and your family. As well as protecting those with health issues from the multitude of air pollutants that gather indoors, those without specific concerns will have peace of mind that the right air purifier will make their environment cleaner.
The air purifiers that are most likely to give you the most benefit, for example those including a HEPA filter, tend to be at the higher end of budgets — generally into the hundreds of dollars. The size of the unit will also play a huge part in the cost — with the larger units that cover a larger area being greater in price.
If you have health concerns, or a recurring allergy, keeping pollutants out of your home with an air purifier is definitely worthwhile. Americans now spend roughly 90% of their time indoors, according to the Environmental Protection Agency. It's here that potentially harmful air is able to build up, meaning there are up to five times higher levels of pollutants indoors, than outdoors. An air purifier can help reduce these levels significantly, though not entirely eradicate them, helping you and those around you breathe easier.
Do air purifiers work?
Depending on the type of allergy, and the trigger, air purifiers have also been found to help reduce the presence of particles in the air that cause allergic reactions, which can in turn cause asthma attacks. Dehumidifiers have also been shown to be helpful for asthma sufferers, during times of high humidity. In cases where your indoor space has little or poor ventilation, air purifiers can also come in useful, especially if you are looking to tackle smoke and the resulting odor.
It is still unclear whether air purifiers do anything to prevent the spread of COVID-19 indoors. The Center for Disease Control (CDC) advises that you should open doors and windows to keep a good flow of air moving indoors — weather permitting, of course. HEPA filters, found in some air purifiers, have been found to remove some viruses from the air.
“Portable air cleaners, also known as air purifiers or air sanitizers, are designed to filter the air in a single room or area, and they have the potential to improve the indoor air quality in that space,” said Ernesta Jones, from the Environmental Protection Agency.
Jones added that HEPA filters can be particularly useful for those suffering from allergies or asthma. “Multiple studies with portable air cleaners that use a HEPA filter have found improvements in one or more allergy and/or asthma symptoms,” she said.
“Several studies suggest that using a portable air cleaner where people are spending time, such as in the bedroom while sleeping, may be more effective than leaving it in a central location, such as in the living room.”
Dr. Deborah Lee, MD and representative for Dr. Fox Online Pharmacy adds that the scientific evidence of research into childhood asthma also indicate that the best air purifiers can significantly help reduce potentially triggering particulate matter within the home.
"In one study, air purifiers were installed in eight houses, with children with childhood asthma. A control group was also studied which did not have an air purifier," she explains. "After 12 weeks, the treatment group showed a clinical improvement in asthma, with better night-time peak flows, whereas these had deteriorated in the control group. The concentration of particulate matter found in the treatment group had decreased by 43%, and this was significantly greater than the control group."
Do air purifiers help with dust?
The best air purifiers say they can help with fine particles in the air, claiming to remove up to 99.9% of particles such as dust, pet dander and other pollutants to improve your indoor air quality. They do this by trapping the particles in a High-Efficiency Particulate Air (HEPA) filter within the air purifier and releasing the cleaned air back into your home.
While there’s plenty of evidence that air purifiers can help improve air quality, whether they can catch all the dust particles in your home is another matter. According to the EPA, air filters are effective at trapping larger airborne particles like dust, pollen, allergens from dust mites and cockroaches, some types of mold, and pet dander. Yet, these particles tend to settle swiftly, making it challenging for air filters to eliminate them entirely from indoor spaces.
However, there is good news for people with allergic asthma, often caused by dust mites. Studies show that air purifiers can help people with allergic asthma by reducing dust mites in the home. For example, a 2021 study published in the Allergol Immunopathol journal has researchers collect dust samples from the bedrooms of children with allergies before and after using a HEPA air purifier. They found that concentrations of dust mites ‘significantly’ decreased in the samples after employing an air purifier.
Another 2020 randomized controlled trial found that air purifiers could reduce particles sized 2.5 microns in the homes of children with asthma, reducing the severity of their symptoms and the amount of medication they had to take to control their condition.
To learn more, Live Science spoke to Dr. Kara Wada, an allergy specialist at The Ohio State University Wexner Medical Center. “Air purifiers are typically most helpful for those with sensitive airways - including those with allergies, asthma and COPD,” said Dr. Wada. “Given that we spend over 90% of our time indoors, ensuring good indoor air quality is important. Air purifiers are most helpful for those with indoor pets and also may be helpful for those with dust allergies. Indoor pet allergens are lighter and more buoyant and stay airborne longer than dust particles which settle more quickly.”
Dr. Wada also advises ensuring your air purifier continues to work at its best by remembering to clean and change the HEPA and activated carbon filters as the manufacturer recommends. “It is important to consider the frequency that filters need to be cleaned or replaced for people with allergies.”
If you want to eliminate tiny dust particles in your home, the EPA suggests choosing an air purifier with a high CADR (Clean Air Delivery Rate) for tobacco smoke – since that includes the smallest particles. Ensure the CADR matches the room or space size where you plan to use it.
In the meantime, discover other ways to remove dust mites from your home with our expert advice.
Do air purifiers help with smells?
The best air purifiers claim to banish bad smells and enhance indoor air quality, but the final verdict on their effectiveness remains unclear.
According to the US Environmental Protection Agency (EPA), air purifiers can help make indoor air cleaner and fresher by reducing pollutants. However, they emphasize that not all odors are guaranteed to disappear. The EPA's 2018 Consumer Guide to Air Cleaners in the Home suggests using air purifiers as a little extra help and proper ventilation to keep the air smelling better and improve overall air quality. So while they might not magically make your home smell like roses, they can make a positive difference, especially if you spend a lot of time indoors.
But when it comes to solid evidence, specifically about air purifiers banishing odors, the research isn't all there. Most studies focus on improving air quality and health rather than tackling smells head-on. For instance, a 2021 systematic review in the Science of The Total Environment Journal looked at more than 20 studies in different settings and found that air purifiers could cut indoor air pollution by up to 92%. A 2020 in the International Journal of Environmental Research and Public Health showed some improvement in regular homes, though not enough to be statistically significant.
So how do these air purifiers work? They filter and trap particles that contribute to bad smells. However, the EPA warns that no filter can catch every odor-causing particle. Also, the size of the room matters. To freshen up a large space, you'll need a bigger air purifier with a higher Clean Air Delivery Rate (CADR) to get the job done.
The ability of air purifiers to tackle specific odors depends on their design. Some models can handle moldy smells, cooking aromas, pet odors, and cigarette smoke. There are even air purifiers equipped with activated carbon filters that can take on gas and chemical odors emitted by household cleaners. But these filters have their limits and can only handle a specific set of gas pollutants. They can't touch carbon monoxide, a dangerous gas emitted by wood-burning stoves and gas fires.
It’s also worth pointing out that quality can vary between brands, and to keep your air purifier working at its best, you’ll need to replace the HEPA filter and activated carbon filter as often as the manufacturer recommends.
So, while air purifiers have the potential to improve air quality and reduce indoor pollution, we're still waiting for solid proof that they're the ultimate odor busters. They might help but don't expect them to zap away all bad smells magically. If you're considering buying an air purifier, it's a good idea to do your research first and understand how different models work before banking on them to keep your place smelling fresh.
What are HEPA filters?
You’ll notice most of the air purifiers for rooms that we tested have something called a high-efficiency particulate absorbing (HEPA) filter. These can remove 99.97 percent of air pollutants from 0.3 microns in size, which basically means they are really effective at getting rid of the majority of indoor air pollutants.
For context, most dust particles are about five microns in size, and pollen is a staggering 10-1,00 microns – all of which a HEPA filter is able to trap and remove.
Perry tells Live Science that while the most effective air cleaners can remove lots of different types of particles, you’ll never get 100 percent pure air.
He says: "The idea of an air purifier is that it’s designed to get rid of the impurities in your home and neutralize any nasties, such as dust, smells, pet dander, smoke, bacteria and viruses.
“Air purifiers work by having a fan that sucks the dirty air in the home into filters. These then remove any impurities before releasing the cleaned air back into the room. It's important to note, however, that it’s impossible to get rid of all particles, which can live on walls, carpets, bedding and hard surfaces.”
Air purifier benefits
For many of us, clean air can make our living space more comfortable. But for those who struggle with respiratory problems, such as allergies, asthma or COPD, the presence of harmful airborne particles can make their symptoms unbearable and directly endanger their health. Similarly, immunocompromised individuals may feel much safer knowing that their air purifier will trap microbes that can make them very sick.
As Perry points out, we may still need more large-scale studies to assess the exact effect of air purifiers on our health, but it’s hard to deny the fact that, for some, these devices may be indispensable.
“It makes sense that the cleaner the air, the easier it is for anyone with breathing problems and susceptible to allergies,” he says. “If you’re an asthma sufferer and want to purchase an at-home air purifier, then it’s a good idea to keep a diary to see if it does make a difference in symptoms. Remember though that an air purifier will not get rid of all impurities so asthma needs to be managed as prescribed by your doctor.”
“The same goes for people who suffer from allergies, the cleaner the air and being able to manage pollen and dust is going to help and will be dependent, of course, on the time of year when pollen count is higher.”
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Lou Mudge is a health writer based in Bath, United Kingdom for Future PLC. She holds an undergraduate degree in creative writing from Bath Spa University, and her work has appeared in Live Science, Tom's Guide, Fit & Well, Coach, T3, and Tech Radar, among others. She regularly writes about health and fitness-related topics such as air quality, gut health, diet and nutrition and the impacts these things have on our lives.
She has worked for the University of Bath on a chemistry research project and produced a short book in collaboration with the department of education at Bath Spa University.