Best Air Purifiers

This guide reviews the best cheap small- and large-room air purifiers for dust, smoke, and pollen, including brands such as Whirlpool and Holmes. Most offer multi-level filtration and HEPA filters for a deep clean. There's also a "smart" model, a purifier for pet owners, and a splurge-worthy recommendation from Rabbit.

What We Considered

Determining which air purifier is best for your needs, especially at the lower end of the price spectrum, can be frustrating. To identify the best budget air purifiers, we turned to comments posted by users on retailer sites including Amazon, Best Buy, Home Depot, Walmart, Target, Staples, as well as manufacturers' websites. For expert advice we looked to sources including Consumer Reports, TopTenReviews,, Wirecutter, TechGearLab, and TechHive, which conduct testing. We also sought online advice from long-standing industry professionals on sites such as and  

We Looked At

Judging the performance of an air purifier starts with the simple question of whether or not it cleans the air. Reviews of our top picks say they handily vanquish the usual airborne irritants and also seem to have good staying power. Users report noticeable differences in dust levels and credit their air purifiers with mitigating sneezing, coughing, and wheezing in humans and animals alike. Our favorite air cleaners also are lauded for reducing pet and cooking odors, alleviating the smoke and smell from cigarettes and cigars, ingesting the floating detritus of construction projects, and for clearing the indoor air in the aftermath of wildfires. For models with an air quality indicator, hard evidence comes in the form of lower readouts, users write.

Keep in mind, however, that airborne particles often settle before being drawn into an air purifier, so even a true HEPA filter sandwiched between other layers of filtration won't eliminate all airborne pollutants. For best results, place the unit away from walls and obstructions, in a spot where the air can circulate freely.

One important thing to remember about noise is that one person's white noise is another person's distraction. Most air purifiers have at least three speed settings. The faster the fan whirs, the noisier it gets. Users report that the lowest setting is the least intrusive, although this reduces the rate at which air is circulated. Some budget models are equipped with a sleep mode that reduces nearly all noise, and some are equipped with a turbo setting that ramps up the action for rapid cleaning.

Our Top Pick

GermGuardian AC4100
Our Picks
GermGuardian AC4100

Designed for areas under 100 square feet, the compact GermGuardian AC4100 3-in-1 air purifier impresses users with its overall effectiveness and multiple levels of cleaning power. Reviews point to a reduction in allergy and asthma symptoms when used in a bedroom, less dust in a closet that was full of it, and protection against germs floating around an office. Some find the fan a noisy distraction, but others shrug it off as background music -- a fitting description for a unit looks more like a stylish little speaker than an air cleaner.

  • Sleek, modern design that sits flat or stands upright.

  • Tiny footprint and incredibly light weight (only about 5 pounds).

  • HEPA filter and charcoal and PCO pre-filter are attached for easier removal and cleaning; indicator light reminds users to change the filter.

  • Optional UV-C light targets germs, bacteria, viruses, and mold.

  • 3 fan speeds to allow for less noise or faster cleaning.

  • Scattered comments about weak performance and not-so-quiet operation.

  • Some reviewers say it's too hard to tell whether the UV-C light is on or off, although others appreciate that it's unobtrusive.

  • Short 1-year warranty.

GermGuardian AC4825

Priced comfortably below $100, the GermGuardian AC4825 easily claims its perch as the company's most popular model. Users with allergies say this air cleaner makes it possible to keep pets. Others commend its stand against cooking odors, mildew, and dust, and praise it for making nighttime breathing much easier. While some are dubious of the UV-C functionality, others swear by it, claiming it's saved them from catching many a viral bug. A few also grouse about the fan noise and minor snafus. But with an average of 4.3 stars from nearly 8,000 user reviews on Amazon, support for this model's value price and overall performance drowns out the critics.

  • Covers up to 155 square feet, more than a typical small-room air purifier.

  • Slim tower profile with a small footprint and recessed handle for portability.

  • Multi-level filtration: pre-filter with activated carbon layer and true HEPA filter; filter-change indicator light.

  • Optional UV-C light zaps viruses and bacteria.

  • 3 fan speeds.

  • Energy Star certified.

  • 3-year warranty.

  • Some reports of limited lifespan, chemical odor, and electrical malfunctions.

  • Some users complain that the blue UV-C light is too bright and interferes with sleep.

Winix 5300-2

Designed for large rooms up to 390 square feet, the Winix 5300-2 gets lots of love from users. Their reviews tell of eyes that have stopped watering, cooking smells that disappear, and lungs that no longer feel irritated. They say the difference in air quality is immediate and palpable and the amount of gunk that shows up on filters is horrifying. Reviews also laud the rich feature set, which comes at a very reasonable price. To be sure, there are some skeptics who argue that the performance of this updated model is not up to par, but the voices of the majority sing its praises.

  • Exceptionally strong performer, according to experts and users, especially in reducing particulate levels and pet odors.

  • Multi-level filtration: carbon filter, true HEPA filter, and optional "PlasmaWave" stage; filter replacement indicator.

  • Electronic controls and digital display with auto dim for nighttime use and multi-setting timer (1, 4, and 8 hours).

  • Smart sensors adjust the fan speed to the current conditions, including odors and volatile organic compounds; light on the control panel changes color according to air quality.

  • 4 fan speeds, including a sleep mode; can be manually controlled.

  • Runs very quietly; manufacturer claims 27.8 dB on the lowest setting.

  • Energy Star certified.

  • 2-year warranty.

  • Scattered complaints about limited effectiveness and durability.

  • Some disappointment with this updated model compared with the original.

Coway AP-1512HH

A darling of expert testing sites, the Coway AP-1512HH scores for high-level performance, cost efficiency, portability, and overall value. User reviews tend to concur, crediting this air purifier with reducing headaches, runny noses, scratchy eyes, and asthma symptoms; clearing cooking odors and smoke from forest fires; and even helping pets suffering from allergies. A relative newcomer, the Coway "Mighty" has impressive cleaning ability for its compact size -- it can clear rooms up to 326 square feet -- and has already attracted a following.

  • Praised by users and experts for its cube-like design, quiet operation, and responsiveness to irritants.

  • Multi-level filtration: washable pre-filter, carbon filter, true HEPA filter, and optional ionizer.

  • 3 fan speeds; auto mode adjusts the speed to the current conditions and eco mode stops the fan when no pollution is detected.

  • Timer with 1-, 4-, and 8-hour settings.

  • Air-quality and filter-change indicators.

  • 3-year warranty.

  • Some users are wary of the ionizer function, even when switched off, given health concerns raised by experts.

  • Scattered reports of limited longevity, odd noises and odors, and negligible effectiveness.

Other Products We Reviewed

The Whispure line of air purifiers from Whirlpool, the brand known for home appliances, continually receives positive reviews from experts and consumers. The devices are especially noted for their durability. While most cheap air purifiers come with three-year warranties at best, Whispure models remain protected for five years.

Offering 500 square feet of coverage, the Whirlpool Whispure AP51030K (starting at $279) is the brand's largest air purifier and boasts solid CADR ratings of 315 for smoke, 325 for dust, and 401 for pollen (experts recommend about two-thirds of the coverage area). This air purifier has a three-step filtration system: An internal fan moves air through the pre-filter to capture large particles, the air is deodorized by the carbon filter, and remaining microscopic allergens are captured by a HEPA filter. There are four fan speeds, as opposed to the standard three found on many inexpensive air purifiers, including a turbo setting ideal for launching high-powered attacks on airborne pollutants. A filter change indicator conveniently notifies users in advance to ensure that replacements will be on hand when needed to keep the unit working at optimal efficiency.

When tested by consumer product experts, the Whirlpool Whispure AP51030K has scored very high for its ability to remove smoke, dust, and pollen, even at its lowest speeds. Customer reviews on Amazon, Walmart, and, a retail site that specializes in air quality products, confirm these findings. Many praise this model for ridding their homes of cigarette fumes or even wildfire smoke. Several were impressed to see the fan visibly removing dust particles and pet hair from the air. Scores of allergy sufferers credit this machine with notable improvements in symptoms of indoor allergies.

For the most part, disappointments focus on the unit's charcoal filter, which some reviewers found less effective at removing unpleasant smells from their homes as they would have liked. Experts say this model is meant to handle only light odors.

The main drawback of this relatively inexpensive machine is that the manufacturer recommends annual replacement of the HEPA filter, which can cost as much as $100, and the carbon filter is to be changed out every three months (we saw packs of four for about $30). These outlays are rather on the high side -- even more so than replacement costs for some more expensive units. But given the comparatively low upfront cost and demonstrated longevity of the machine, the Whirlpool Whispure AP51030K remains an excellent value overall. It's also Energy Star qualified, so it should be slightly easier on your electricity bill.

Hamilton Beach True Air 04386

A hefty majority of reviewers cheer the Hamilton Beach True Air 04386 for keeping the air breathable in homes with pets and residents with limited tolerance for pollen, mold spores, and dust mites. Some consider this the best air cleaner they've ever used, and many report that it rids the air of particulates almost noiselessly when set on low. Compact enough to move around the house or take on vacation, it can clear rooms up to 160 square feet. Most reviewers appreciate the easy-clean, money-saving design, with the permanent HEPA-grade filter, although a few feel cheated that it falls a tad short of the "true" HEPA standard.

  • Permanent HEPA-grade filter can be cleaned with a vacuum; no need to buy replacements.

  • Tabletop size; can be positioned vertically or horizontally.

  • Good for trapping allergens.

  • 3 fan speeds to adjust for lower noise or faster performance.

  • Runs very quietly, according to many reviews.

  • Only 1 level of filtration; no carbon filter to catch irritants from chemicals or grease.

  • Some users wish it had a "true" HEPA filter capable of trapping 99.97 percent of airborne irritants as small as 0.3 microns, instead of 99 percent of particles as small as 3 microns.

  • Scattered complaints about ineffective performance.

  • Short 1-year warranty.

Although the South Korean brand Winix is a relative newcomer to the U.S. market, its air purifiers have earned high praise from experts and receive very positive reviews. The Winix PlasmaWave 5300 (starting at $168) is a top performer -- the brand's best-selling model. This four-speed, Energy Star-certified unit with a true HEPA filter, as well as carbon pre-filter, uses patented PlasmaWave technology to break down air pollutants and odors. The company worked with researchers at Drexel University to develop this cutting-edge cleaning system. Yet despite the high-tech functionality of the Winix PlasmaWave 5300, the manufacturer created this unit with an eye toward keeping the price relatively low. Stripped of a few of the "extras" found in more recent models (most notably, a remote control), this one still delivers powerful performance that at least one tester claims is pretty much comparable to that of its updated, remote control-touting cousin, the Winix PlasmaWave 6300.

At 16.3 inches wide and 21.7 inches high, this relatively large air purifier is designed for big rooms up to 350 square feet. The unit's CADR ratings are in keeping with this coverage area: a solid 235 for smoke, 216 for dust, and 251 for pollen. It also features a sleep mode, an electronic display, and an automatic sensor that can cycle the unit through three stages of cleaning based on changes in room air quality.

Reviews on Amazon, which number nearly 1,000, are very favorable toward this model. Across these reviews, the Winix PlasmaWave 5300 is noted as effective for relieving common allergy symptoms. Countless reviewers write of stuffy noses being cleared, trouble breathing lessened, and allergy symptoms alleviated. The Winix PlasmaWave 5300 has scored points for smoke removal, as well, with several reviews mentioning that it quickly clears out rooms well enough to calm smoke detectors. Several also note that the machine's odor-sensing abilities are extremely sensitive, and it kicks into the most powerful mode the minute it sniffs anything amiss. At the same time, some complain that the noise emitted at high power levels is slightly unpleasant.

It's also worth noting that, although the PlasmaWave technology is not supposed to produce any ozone byproducts, which can be harmful to health, there is still some debate as to whether it's completely ozone-free. While any emissions it may be producing are within government safety limits, and much lower than those released by ionizing air purifiers, consumers may choose not to use the "Wave" function on the machine and simply rely on the HEPA filter to do the trick. (A reviewer explains how to turn off this function without the benefit of a remote control.)

Finally, although consumers save on energy costs with this efficient model, it still requires periodic spending on filter replacements. The Winix PlasmaWave 5300 is equipped with a light to signal it's time for a change. A few users express dissatisfaction with models requiring more frequent filter changes than originally recommended by the manufacturer.

Holmes HAP242-NUC-1

Holmes air purifiers have long earned praise for their excellent value, quickly clearing air of litter box and food odors, hairstyling and garage fumes, particles drifting out of air ducts, pollen, smoke, and more. The desktop Holmes HAP242-NUC-1 is no exception. It's intended for small rooms up to 109 square feet, and scores of users tell of placing it in bathrooms, bedrooms, and kitchens to great effect. It's also said to be a good air purifier for the office. The HEPA-type filter traps fewer pollutants than a "true" HEPA filter (99 percent of particles as small as 2 microns vs. 99.97 percent of particles as small as 0.3 microns), but users don't seem to notice the difference. Those wishing for greater cleaning power can easily switch to a higher-grade filter, which also needs replacing less frequently.

  • Very compact, desktop footprint; can be set flat or upright.

  • Multi-level filtration: proprietary filter with extra odor-absorbing capacity (carbon, baking soda, and zeolite) as well as a HEPA-type filter.

  • Users can upgrade to a variety of specialized Aer1 filters for more concentrated or customized cleaning.

  • 3 fan speeds.

  • 3-year warranty.

  • Some users object to the ionizer feature, despite the option to turn it off.

  • Scattered claims about ineffective performance, assorted malfunctions, chemical odors, and unacceptably loud noise.

The Ionic Pro Turbo from Envion (starting at $135) is less than half the cost of popular ionic air purifiers such as Sharper Image’s Ionic Comfort Quadra. With its low price and an ideal coverage range for small apartments -- up to 500 square feet -- this is an attractive option for many consumers. A slim, black tower design makes it less obtrusive and more "stylish" than bulkier models that cover a similar size area.

While reviews traditionally mention “white noise” and complain about more intrusive rattling from air purifiers with filters and fans, the technology employed by the Ionic Pro Turbo is completely silent. It relies on ionization to electrify and capture a claimed 99.9 percent of airborne pollutants greater than 1 micron in size. In customer reviews on the Walmart website, the Ionic Pro Turbo garners an average of 4.2 stars out of 5 and is frequently recommended for use in bedrooms and other areas where quiet is desired. Several reviewers express amazement at the amount of gunk the purifier collects on its blades, and many credit the machine with alleviating allergy symptoms and breathing difficulties (one used it while recuperating from lung surgery).

Because it doesn't use filters, the Ionic Pro Turbo doesn’t incur the ongoing maintenance costs associated with regular replacement. Even when holding up this model against similar ionic air purifiers, many reviewers point to the front-loading collection blade, which doesn’t require a lengthy and intricate process to remove accumulated dirt and debris from its blades. The Ionic Pro Turbo also displays an alert and automatically shuts down when it requires deep cleaning.

Attractive, affordable, easy to clean, and easy on the ears -- it sounds almost too good to be true. And, indeed, there may be more than a few catches here. Ionic technology is not without its foibles, as discussed at length in our air purifier buying guide. Although ionic air purifiers adhere to government safety standards, they are known to emit low levels of ozone, a potential health risk. There are also questions about their effectiveness at removing significant amounts of pollutants from the air, as a great deal of the residue not captured by the blades tends to settle on walls and furniture, creating stains. For this model in particular, there are enough reports on Amazon and elsewhere of faulty models that broke down soon after initial use to give us pause. In the final assessment, it seems that consumers get both more and less than they bargained for with the Envion Ionic Pro Turbo.

lg airfree onix 3000 250

For a fairly low price, the Airfree Onix 3000 (starting at $266) boasts coverage for areas up to 650 square feet; ease of use (just plug it in and walk away); low operating costs; and eco-friendly technology for attacking germs, mold, pollen, mildew, and other allergy offenders lurking in the air.

Airfree uses a patented Thermodynamic Sterilizing System said to remove 99.99 percent of microorganisms from the air. Essentially, air is drawn into the unit by convection, then subjected to 400-degree heat, which immediately incinerates any microorganisms present. The cleansed air is cooled and sent back out into the room. The process is pretty safe and simple, but not without its flaws.

An expert review on the retail site Allergy Buyers Club notes one big drawback of the purification process: Because it targets organic pollutants and uses no fan or filters, it doesn't combat chemical pollutants or odors caused by these sorts of substances. Also, there’s no “turbo” switch here. It takes a recommended seven to 10 days of continuous usage, if not a month, to get optimal results out of this air purifier. Good thing it's silent and relatively small, with a pod-like design that helps it blend into the background. A blue “nightlight” on top keeps users from tripping over it in the dark.

Perhaps not surprisingly, given the novelty of Airfree's TSS technology, user reviews for the Airfree Onix 3000 are more than a little mixed. Many negative reviews onAmazon come from buyers who insist they can't even tell if the air purifier is working. And it does seem as if more than a few of the reviewed units were duds. On the other hand, positive user reviews on Amazon are effusive, and the Airfree Onix 3000 has earned an average of 4.6 out 5 stars from nearly 60 Allergy Buyers Club customers. Some reviewers say they’ve seen dramatic improvements in their allergy symptoms and breathing overall.

lg germ guardian ac4020 3 in 1 250

Although there are precious few Germ Guardian AC4020 reviews online, the fact that parent company Guardian Technologies has a difficult time keeping the model in stock suggests sales are high. And there are a lot of reasons to believe this little air purifier would be coveted by consumers.

First, at only a little more than 7 inches high, the AC4020 (starting at $55) is an ideal size to be placed on a desk or bedside table. There’s also a lot of potential air-cleansing power packed into this small-room model, which covers areas up to 93 square feet. The AC4020 is armed with a combined HEPA-charcoal filter that attacks odors as well as 99.97 percent of particles larger than 0.3 microns in size. This "3-in-1" model also employs the latest in UV technology to further sanitize the air and kill germs, viruses, and bacteria. Additional features include three fan settings, a filter-change indicator, and an aesthetically pleasing design. Unlike many other air purifiers, the Germ Guardian AC4020 is meant to be proudly displayed, not stashed in a corner.

Of the few reviews on Amazon, those from customers unhappy with their purchases cite the fact that the AC4020 is a lot noisier than they expected given its diminutive size. In an extended 4-star review, however, one buyer insists that the sound issue is pretty much the only thing that can be criticized about this model, which in all other ways is well worth the relatively small amount of money spent. (Use it on the lowest setting to minimize noise.) The design allows users to save on filter replacement costs, as it requires only a single filter (selling for about $15) to be changed at six-month intervals, rather than separate HEPA and charcoal filters. Taking all that into account, this little black box seems like a bargain.

Whirlpool Whispure WP500

A previous model, the Whirlpool AP51030K, earned plaudits from users and experts alike for its features and performance. It scored points with testing sites for removing common irritants like dust, pollen, and smoke at both high and low speeds, as well as quiet operation. The new Whispure WP500P is said to be quieter still and is Energy Star certified. Based on the few available user reviews, we expect that it will at least meet the standards set by the older model, including removal of 99.97 percent of particulates as small as 0.3 microns, thanks to the HEPA filter.

  • Makes a noticeable difference in air quality almost immediately, reviewers say.

  • Air is refreshed 4.8 times an hour in rooms up to a very spacious 490 square feet.

  • HEPA filter and active carbon pre-filter for multi-level cleaning.

  • Indicator light to signal when the filters need replacing.

  • Electronic controls, including a timer and 8-hour sleep mode.

  • 4 fan speeds; "turbo" setting.

  • Engineered to run quietly; Whispure models are known for hitting less than 50 dB on max speed.

  • Energy Star certified.

  • 5-year warranty on the motor and 30-day money-back guarantee that it will prove quieter than comparable models.

  • Only a handful of consumer reviews for this particular model; we relied on reviews of a previous version in making this pick.

  • Some disappointment with the build quality of that predecessor, and the 1-year standard warranty is short.

Honeywell HPA250B Bluetooth

The big lure of the Honeywell HPA250 is its smart capabilities. Many users like the convenience of the auto features and the ability to create an on/off schedule, all for a relatively modest price. Some contend that the app isn't quite ready for prime time, however. As far as air purification goes, the consensus opinion is that this model does a fine job, and its large coverage area is appreciated. For those skeptical of the smart technology, Honeywell offers non-Bluetooth models with almost identical specs for rooms of different sizes (HPA100, HPA200, and HPA300) that are highly regarded by testing sites.

  • User-friendly and effective against odors, reviewers write, with a noticeable difference in the amount of dust and the breathability of the air.

  • Can be operated remotely with a smartphone or tablet via Bluetooth.

  • Auto settings on the app can trigger operation based on specified levels of allergens in the outside air.

  • Multi-level filtration: activated carbon pre-filter and true HEPA filter.

  • Sensor for auto-on to clear out volatile organic compounds (VOCs).

  • 4 fan speeds/"purification levels."

  • Air is cleaned up to 5 times an hour in spaces up to 310 square feet.

  • Customizable on/off schedule; programmable timer for 1 to 18 hours.

  • Indicator lights for each filter; dimmer for all LED lights.

  • Energy Star certified.

  • 5-year warranty.

  • Some users aren't thrilled with the app, citing a limited proximity range, problems syncing, and functions not working.

  • Some grumbling in reviews about excessive noise at higher speeds and a few doubts concerning overall effectiveness.

GermGuardian AC5250PT

Engineered to meet the needs of pet-filled households, the GermGuardian 3-in-1 Pet Pure suits pet-free homes, as well. Reviews indicate that it helps people who struggle with allergies or snoring, work in rooms without windows, or are plagued by the smell of a neighbor's secondhand smoke -- all while tackling the irritants unleashed by the animal kingdom. Although this model is engineered for small to midsize rooms up to 193 square feet, some users tell of good results in larger spaces.

  • Rids the air of irritating evidence of pets (both four-footed and flying), including dander, hair, and odors, reviewers say, as well as common airborne irritants.

  • Sleek, tower-like profile.

  • Multi-level filtration: pre-filter with activated charcoal layer and true HEPA filter with special anti-microbial filter treatment ("Pet Pure") to protect against mold and bacteria; UV-C light.

  • 5 speeds, including sleep mode; very quiet on lower speeds, users say.

  • Digital display; filter change indicator; timer for up to 8 hours (at 1-hour intervals).

  • Energy Star.

  • 5-year warranty.

  • Blue UV light is bothersome at night, according to some users.

  • Scattered reports about limited longevity and various malfunctions.

Rabbit Air BioGS 2.0 SPA-550A

The feature-rich Rabbit Air BioGS 2.0 helps many users breathe easier and sleep better, reviews indicate, regardless whether the pollutants come from industrial emissions, in-home construction, or normal environmental conditions. Many keep it going at all times, counting on the air-quality sensors to signal the fan to increase or decrease speed as needed. With award-winning design and incredibly quiet performance, Rabbit Air products command a premium, but conveniences like the remote control, long-life filters, and energy efficiency help soften the blow of the hefty upfront cost, as does the large coverage area and customer service that several users call simply outstanding.

  • Extremely quiet operation (22.8 dB on low).

  • Reviewers praise this model's overall air-cleaning ability.

  • Powerful enough to clear a 550-square-foot room or even a small studio apartment.

  • Multi-stage filtration: pre-filter, charcoal-based activated carbon filter, true HEPA filter, and optional ionizer; filter-life indicator.

  • Pre-filter is permanent and can be washed; HEPA and carbon filters are designed to last up to 3 years.

  • 5 speeds; auto adjusts to particle and odor irritants.

  • Electronic controls with automatic dimming, air-quality indicator lights, and remote.

  • Energy Star certified.

  • 5-year warranty; 24/7 customer service.

  • Some skepticism about effectiveness, notably when challenged by odors, secondhand smoke, and pet dander.

  • Some pushback regarding the relatively high price tag.

Holmes HAP424-U

Unlike some of the competition, the Holmes HAP424-U HEPA-Type Tower seems to polarize reviewers. More than one-third of consumers reviewing this model on Amazon are critical, while the rest of the reviews on Amazon and other retail sites give it a fairly enthusiastic thumbs-up. Despite that support, a large number of complaints cite total product failure soon after purchase. For consumers who want a no-frills, small-room air purifier, there are products in the same price range that aren't quite so hit or miss.

  • Does an adequate job on dust, pet hair, low-level allergens, and other airborne particulates, some reviews say.

  • Covers a fairly large area (up to 180 square feet) for the price.

  • Washable pre-filter treated with baking soda, HEPA-type filter for multi-level cleaning, and optional ionizer; can also use a "true" HEPA filter or any proprietary Holmes filter.

  • 3 speeds.

  • Filter-change indicator light.

  • 3-year warranty.

  • Large compared with many newer, tower-style models.

  • Numerous reports concerning strange noises, burning smells, and product failure straight out of the box or within days or weeks of purchase.

  • Runs very loudly and can get louder over time, according to users; one review on Amazon refers to it as "the old jalopy."

  • Although the ionizer can be turned off, it remains a controversial feature.

Buying Guide

Choosing an Air Purifier

Government data show that Americans spend nearly 90 percent of their time indoors, where the air quality is generally far worse than outside. A portable air purifier can make a dramatic difference for those plagued by asthma and allergies, pet dander and odors, fumes from tobacco smoke, or other irritants. put budget air purifiers through the filter of expert and consumer reviews to identify the best small-room air purifiers under $100 and the best models for large spaces costing less than $250. All our top picks handily help rid the air of contaminants on the cheap, making the atmosphere in your home feel fresher and more breathable.

Do Air Purifiers Really Work?

Medical experts warn that not even the very best air purifier can make any health claims, and the EPA bluntly advises that air cleaners be only part of an air treatment plan that includes controlling the source of pollutants and improving ventilation. Still, reviewers generally agree that high-performing air purifiers are worth the investment. Many consumers with allergies, respiratory problems, sensitivity to odors, and pets report an air purifier offers welcome relief in the form of improved comfort and health.

Pricey vs. Cheap Air Purifiers

The market for air purifiers is growing, with new brands and technologies emerging at a steady clip. High-end names such as IQAir, Blueair, Austin, and Alen sit well outside the budget zone with air cleaners that often start at $500 or so. In general, pricey air purifiers do a better job scrubbing the air and pushing it back out, run more quietly and efficiently, and feature more advanced filter systems than cheaper models. Some hit medical-grade air-quality standards. They often boast conveniences such as remote and smart controls and come with longer warranties.

Still, the inexpensive air purifiers highlighted on our list can hold their own. Bearing the labels of trusted household appliance brands such as Whirlpool and Hamilton Beach, along with specialty brands like Holmes, Winix, and GermGuardian, they may be short on bells and whistles, but they win endorsements from users and experts for effective and reliable performance at a value price.

Air Purifier Types

The first step in choosing an air purifier is to identify the air quality issue(s) you want to address, such as dust, pollen, chemical vapors, and so on. Some cheap air purifiers focus more on particulates than on odors or gases, and vice versa. The Environmental Protection Agency dedicates an entire section of its website to the topic of indoor air quality and the performance characteristics of different types of air cleaners.

Models that clean the air with a physical filter are the most common and arguably the most effective, especially when outfitted with a high efficiency particulate air filter. In this setup, air is pulled in by a fan and passes through a filter that traps airborne irritants. The cleaned air is circulated back into the room. HEPA filters come in several grades, or classifications, with a "true" HEPA filter capable of trapping 99.97 percent of airborne particles -- think dust, pollen, mold spores, pet dander -- as small as 0.3 microns (the average human hair is 50 microns across).

Several of our top picks boast a true HEPA filter, and anyone who suffers from severe allergies or asthma should opt for an air cleaner with the highest-grade HEPA filter. Others on our list use "HEPA-grade" filters that capture 99 percent of invisible airborne particles. Reviewers hold that some of these models are absolutely viable choices for mild or seasonal allergies.

The best air purifiers rely on multi-level filtration. Typically this involves a pre-filter that traps larger particles, like pet hair and dander, and an activated carbon filter that helps absorb odors, smoke, and volatile organic compounds emitted by draperies, carpeting, upholstery, household cleaning agents, paints, varnishes, waxes, and certain building materials, among other substances. In some models, the pre-filter and carbon filter form one unit; in others they are separate.

The number of times air flows through the filter each hour is referred to as "air changes per hour, or ACH. Many experts recommend a minimum of four, although this specification is not often reported by the manufacturer.

UV Air Purifiers

Some models, including several of our picks, also incorporate an ultraviolet light (UV-C) that's meant to destroy bacterial microorganisms as the final level of filtration. Experts note, however, that the amount of time required to do the deed is longer than the amount of time the particles are exposed to the light, thus minimizing the technology's effectiveness. Reviewers who keep an air purifier in their bedrooms often gripe that the light on some of these models is too bright for nighttime use. It can be switched on or off at the user's discretion.

Ozone Air Purifiers

The most controversial air purifiers intentionally convert air molecules into ozone to tackle odors. The EPA warns that ozone can damage the lungs and, at the very least, exacerbate respiratory problems. Consequently, many experts recommend against ozone-generating air purifiers.

Ionic Air Purifiers

Ionic air purifiers also produce small amounts of ozone, but supposedly at levels that do not exceed current safety standards. Instead of using a filter, ionic air purifiers catch contaminants on electrically charged plates/blades or cells. They send out negatively charged ions that attach to airborne particulates, which are then pulled down out of the air and lured back to a positively charged collector plate. Reports dating back to at least 2003 have questioned the efficacy of air ionizers. And yet, these types of purifiers remain popular with some consumers, at least in part because they have no fan, so they're nearly silent. But the absence of a fan also means the machine catches only contaminants that happen to drift within close range. Experts note that often the particles on the charged plates can loosen and be recirculated, and some wind up settling on other surfaces.

Our inclination is to avoid models outfitted with ionic technology unless they include other means of removing airborne irritants and offer the option of shutting it off. Several of our picks include an ionizer as an optional step in the air cleaning process.

The Winix line of air cleaners uses a proprietary PlasmaWave as the final stage in the filtering process. This technology emits both positively and negatively charged ions to combine with water vapors in the air to create oxidizers that neutralize germs, odors, vapors, and gases without emitting any ozone. Also, the charge on these plasma ions is weaker, so they dissipate more quickly, leaving less potentially harmful particles floating about in the air. The PlasmaWave function can be turned on or off.

Large vs. Small Room Air Purifiers

The next step in choosing an air cleaner is determining where you will place it, as the room's square footage affects both size and price. Small-room models intended for less than 200 square feet are always cheaper than large-room air purifiers meant for 350 square feet and up, regardless of features or performance. But a model that's too small for the space won't filter and recirculate the air into the room often enough. Many rooms straddle the line between small and large, so err on the large side when deciding on the best model for your space.

Features Comparison

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Review Score:
Product Title
Coverage Area
Filtration Technology
Fan Speeds
Product Title
Coverage Area
Filtration Technology
Fan Speeds

GermGuardian AC4100

< 100 sq. ft.
HEPA, carbon, optional UV-C light
66 dust 76 pollen 50 smoke
1 year

GermGuardian AC4825

155 sq. ft.
HEPA, carbon, optional UV-C light
118 dust 125 pollen 104 smoke
3 years

Winix 5300-2

Portable (freestanding)
360 sq. ft.
HEPA, carbon, optional PlasmaWave oxidation
4 (with auto adjust and sleep mode)
243 dust 246 pollen 232 smoke
2 years

Coway AP-1512HH

Portable (freestanding)
326 sq. ft.
HEPA, washable pre-filter, carbon, optional ionizer
3 (with auto adjust and eco mode)
246 dust 240 pollen 233 smoke
3 years

Holmes HAP242-NUC-1

109 sq. ft.
HEPA-type, washable pre-filter, carbon, ionizer
70 smoke
3 years

Hamilton Beach True Air...

160 sq. ft.
HEPA-grade permanent
Not specified
1 year

Whirlpool Whispure WP500

Portable (freestanding)
490 sq. ft.
HEPA, carbon
4 (with sleep mode)
315 cfm
1 year; 5 years motor; 30-day ‘quiet guarantee’

Honeywell HPA250B Bluetooth

Portable (freestanding)
310 sq. ft.
HEPA, carbon
4 (with app-control and auto-operation)
190 dust 180 pollen 200 smoke
5 years

GermGuardian AC5250PT

193 sq. ft.
HEPA with antimicrobial “PetPure” treatment, carbon, optional UV-C light
5 (with sleep mode)
123 dust 128 pollen 116 smoke
5 years

Holmes HAP424-U

180 sq. ft.
HEPA-type, pre-filter with baking soda, optional ionizer
116 smoke
3 years